Substituent and temperature controlled tautomerism: Multinuclear magnetic resonance, X-ray, and theoretical studies on 2-phenacylquinolines

Proton-transfer equilibria in chloroform solution of twelve 2-phenacylquinolines were studied by 1H, 13C and 15N NMR spectroscopies. The (Z)-enaminone form stabilized by an intramolecular hydrogen bond was found to prevail in all cases. Electron-donating substituents in the phenacyl part of the molecule lead to an increase of the ketimine form (to 33% for p-NMe2). Variable temperature 1H NMR measurements show that higher temperatures have the same effect. The negative logarithm values of the equilibrium constant, pKT, were found to be linearly dependent on Hammett σ substituent constants. The pKTvs. temperature correlation also has a linear character. In general, strong electron-withdrawing…

Interaction of aminomethylated resorcinarenes with rhodamine B

The interaction of aminomethylated resorcinarenes with a red xanthene dye, rhodamine B, was investigated in chloroform, methanol and chloroform–methanol solutions using UV-vis, NMR and fluorescence spectroscopy. Aminomethylated resorcinarenes 1 and 2 shift the rhodamine B equilibrium from the zwitterion to the lactone form unlike reference compounds 3 and 4, which do not contain tertiary amino groups at the upper rim, giving an example of how supramolecular hosts can influence the equilibrium of rhodamine B isomers.

Effect of a Rigid Sulfonamide Bond on Molecular Folding: A Case Study

A disulfonamide compound with bulky aromatic side chains was prepared, and its properties as a potential building block for foldamers were evaluated. Two different solvate crystal forms of the compound were identified and compared to the structures of an analogous oligoamide and related disulfonamides. The disulfonamide is unfolded in one of the solvates, whereas in the other one, a loosely folded conformer stabilized by an intramolecular hydrogen bond is found. Density functional calculations indicated that the loosely folded conformer is slightly more stable than its unfolded isomer. The calculations also identified a third, more tightly folded and more extensively hydrogen bonded, confor…

Synthesis and structure of mono-bridged resorcinarene host: a ditopic receptor for ammonium guests.

The synthesis and structural properties of tetramethoxy resorcinarene mono-crown-5 (1) are described. The binding characteristics of 1 toward acetylcholine and tetramethylammonium salts were investigated by 1H NMR titration. It was observed that the cavity of 1 provides a better fit to acetylcholine compared to the smaller tetramethylammonium cation, as acetylcholine is able to interact with both the crown ether moiety and the free hydroxyl groups of receptor 1 simultaneously.

Melamine induced conformational change of ethyl resorcinarene in solid state

When ethyl resorcinarene (1) and melamine (2) are co-crystallised, all intramolecular hydrogen bonds keeping the resorcinarene in crown conformation are broken causing an unexpected conformational change to boat, and a highly ordered hydrogen bonded network is formed.

Aromatic Bridged Bis-phenol A Derived Cyclophanes. Synthesis, Molecular Structure and Binding Properties Toward Quats

Three novel polyoxyethylene bridged bis phenol A derived cyclophanes, {\rm 2 -- 4,} with additional aromatic units in the bridge to increase the number of cation–π interactions with guest cations, were synthesized and characterized by means of X-ray crystal structure determinations. The binding properties of these receptors toward tetramethylammonium (TMA), N-methylpyridinium (NMP), acetylcholine (ACh) and N-methylquinolinium (NMQ) salts were evaluated by means of 1H NMR spectroscopy and compared with those of the previously reported receptor 1.

Structural study of ethyl 3-arylcarbamoyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2-carboxylates: conformation and transmission of substituent effects across the diazabicycloheptene ring

Nine new ethyl 3-arylcarbamoyl-2,3-diazabicyclo[2.2.1]hept-5-ene-2-carboxylates were prepared by a [4 + 2] cycloaddition and their FTIR, 1H, 13C and 15N NMR spectra were measured and assigned. Single crystals were grown for five compounds and their X-ray data were obtained. The electronic structure and the conformations were calculated by the semi-empirical AM1 method. Using correlations between the spectral, empirical and theoretical structural data, the transmission of substituent effects and the preferential conformation connected with the consecutive double nitrogen inversion and regarding the mutual orientation of NH and CO bonds were investigated. The results are compared with those f…

The Structural Diversity of Benzofuran Resorcinarene Leads to Enhanced Fluorescence

An unexpected and previously unknown resorcinarene mono-crown with a fused benzofuran moiety in its macrocyclic core was obtained as a byproduct from a bridging reaction of tetramethoxy resorcinarene with tetraethylene glycol ditosylate. The formation of the fused benzofuran moiety in the resorcinarene macrocycle resulted in a unique rigid and puckered boat conformation, as shown by XRD studies in the solid state. Modification of the macrocycle was also observed to affect the photophysical properties in solution by enhancing the fluorescence brightness compared with a conventional resorcinarene macrocycle. The fluorescent properties enabled unique detection of structural features, that is, …

NMR spectral and X-ray structural investigation of 1,3-bis(2-quinolyl)-2-(p-chlorophenyl)-2-propanol

Abstract 1,3-Bis(2-quinolyl)-2-(p-chlorophenyl)-2-propanol (BQCP) has been prepared and characterised by 1H, 13C, 15N NMR spectral and X-ray structural parameters. The methylene protons of BQCP are diastereotopic in solution (CDCl3) as revealed by 1H NMR. In crystalline state there exists an intramolecular hydrogen bond O–H⋯N with one of two nitrogen atoms in BQCP. Variable temperature 1H NMR and PFG 1H, 15N HMBC runs show that in solution BQCP shows C2v-symmetry (both CH2-2-quinolyl fragments are equivalent) in NMR-time scale due to a fast exchange of the hydrogen bond from one nitrogen to the other even at 223 K.

Resorcinarene Podand with Amine-Functionalized Side Arms – Synthesis, Structure, and Binding Properties of a Neutral Anion Receptor

The synthesis and structure of a neutral resorcinarene host bearing four amine-functionalized side arms is described. The anion binding properties were investigated in solution by 1H NMR spectroscopic titration and diffusion experiments and in the gas phase by mass spectrometric studies. It was observed that in solution 1:2 (host/guest) complexes were formed between the resorcinarene host and the basic fluoride and acetate anions, whereas in the gas phase 1:1 complexes with other anions (Cl–, HCOO–, NO3–, and BF4–) were detected additionally. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Crystal Engineering Studies of the Complexes of Ethyl Resorcinarene with Aromatic Nitrogen Heterocycles

Five X-ray structures of complexes of ethyl resorcinarene with aromatic nitrogen heterocycles (imidazole, 1,2,4-triazole, pyridine, pyrazine, 2-pyridylmethanol and quinoline) show that ethyl resorcinarene spontaneously forms molecular inclusion complexes with five- and six-membered aromatic nitrogen heterocycles via π π and CH π interactions. However, with 10-membered quinoline, no molecular inclusion complex is formed. Instead, quinoline manifests crystal lattice inclusion.

Influence of lower rim C-methyl group on crystal forms and metal complexation of resorcinarene bis-crown-5

C-methyl resorcinarene bis-crown-5 (1) with pendant methyl groups at the lower rim was prepared and crystallized in various solvent mixtures with and without selected metal salts. The crystal structures of two polymorphic forms of unsolvated 1 (1-I and 1-II), three solvates (acetonitrile, chloroform and dichloromethane-methanol), and three metal complexes with silver and cesium salts were obtained. The lower rim methyl groups and the block shape of the host promote crystal packing in brick-wall type assemblies, in which the binding cavities are efficiently filled by the crown bridges. Thus, solvents are found in the interstitial space or coordinated to the crown bridges on top of the cavity…

1H, 13C NMR spectral and single crystal structural studies of toxaphene congeners. Quantum chemical calculations for preferred conformers of 2,5-endo,6-exo,8,9,9,10,10-octachloro-2-bornene and their DFT/GIAO 13C chemical shifts

Abstract The 1H and 13C NMR chemical shifts for six toxaphene congeners: 2-exo,3-endo,6-exo,8,9,10-hexachloro- (1), 2-exo,3-endo,5-exo,9,9,10,10-heptachloro- (2), 2-exo,3-endo,6-exo,8,9,10,10-heptachloro- (3), 2-exo,3-endo,5-exo,6-endo,8,9,10-heptachloro- (4), 2-exo,3-endo,5-exo,6-endo,8,9,9,10-octachlorobornane (5) and 2,5-endo,6-exo,8,9,9,10,10-octachloro-2-bornene (6) are reported. Their chemical shift assignments have been obtained by means of Pulsed Field Gradient (PFG) Double Quantum Filtered (DQF) 1H,1H correlation spectroscopy (COSY), PFG 1H,13C Heteronuclear Multiple Quantum Coherence (HMQC) and PFG 1H,13C Heteronuclear Multiple Bond Correlation (HMBC) experiments. A single crystal…

Ion Pair Recognition of Quaternary Ammonium and Iminium Salts by Uranyl-Salophen Compounds in Solution and in the Solid State

Efficient ditopic receptors for quaternary ammonium and iminium salts have been obtained upon functionalization of the uranyl-salophen unit with conformationally flexible side arms bearing phenyl or beta-naphthyl substituents. Binding affinities in chloroform solution have been measured for a large number of quaternary salts comprising tetramethylammonium (TMA), tetrabutylammonium (TBA), acetylcholine (ACh), N-methylpyridinium (NMP), and N-methylisoquinolinium (NmiQ) cations. Recognition of the anion partner is ensured by coordination to the hard Lewis acidic uranyl center, whereas cation-pi/CH-pi interactions of the quaternary ions are established with the aromatic pendants. The role of th…

Correlating Solution‐ and Solid‐State Structures of Conformationally Flexible Resorcinarenes: Significance of a Sulfonyl Group in Intramolecular Self‐Inclusion

Abstract The synthesis of tetramethoxyresorcinarene podands bearing p‐toluene arms connected by ‐SO3‐ (1) and ‐CH2O‐ (2) linkers is presented herein. In the solid state, the resorcinarene podand 1 forms an intramolecular self‐inclusion complex with the pendant p‐toluene group of a podand arm, whereas the resorcinarene podand 2 does not show self‐inclusion. The conformations of the flexible resorcinarene podands in solution were investigated by variable‐temperature experiments using 1D and 2D NMR spectroscopic techniques as well as by computational methods, including a conformational search and subsequent DFT optimisation of representative structures. The 1H NMR spectra of 1 and 2 at room te…

Structural analysis of two foldamer-type oligoamides – the effect of hydrogen bonding on solvate formation, crystal structures and molecular conformation

Author's Final draft The crystal structures and molecular conformations of two foldamer-type oligoamides were analyzed. One polymorphic form and seven solvates were found for N¹,N³-bis(2-benzamidophenyl)benzene-1,3-dicarboxamide (the benzene variant), and two polymorphic forms and six solvates for N²,N⁶-bis(2-benzamidophenyl)pyridine-2,6-dicarboxamide (the pyridine variant). Three crystal structures of the benzene variant and seven structures of the pyridine variant were solved using single crystal X-ray diffraction. The crystal structures showed that the different modes of intramolecular hydrogen bonding strongly affect the conformation and folding of the molecules, which is most evidently…

Self-assembling resorcinarene capsules: solid and gas phase studies on encapsulation of small alkyl ammonium cations

The self-assembling process of unsubstituted resorcinarenes (1, 2 and 3) to dimeric capsules encapsulating small tetra-alkyl ammonium cations 4–7 has been studied in solid and gaseous states by X-ray crystallographic and mass spectrometric methods. Hydrogen bonding and cation-π interaction as well as the proper encapsulation in the empty cavity of the capsule appear to be the most important interactions in the capsule formation process. Competitive mass spectrometric studies clearly indicated preference of the tetramethyl ammonium cation (4) over tetraethyl ammonium cation (6) and especially tetrabutyl ammonium cation (7). The crystal structures of altogether eight dimeric capsules of resor…

Comparison of the polymorphs and solvates of two analogous fungicides—a case study of the applicability of a supramolecular synthon approach in crystal engineering

The polymorphism and solvate formation of thiophanate-ethyl (TE), a fungicidal active, were investigated by solvent crystallization and compared to a close analogue, thiophanate-methyl (TM). Four polymorphs and seven solvates of TE were found and structurally compared with the previously found two polymorphs and fourteen solvates of TM by analyzing the hydrogen bonding patterns and using fingerprint plots, packing coefficients and lattice energies. TE and TM have the same functional groups that can build identical supramolecular synthons. Despite the strong similarities, the polymorphs and solvates of the two actives show significant differences in hydrogen bonding and packing. The results …

Model studies on a diastereoselective synthesis of the C(33)–C(37) fragment of Amphotericin B

Abstract A new, short and highly diastereoselective synthetic route aiming at the C(33)–C(37) fragment of Amphotericin B has been developed. Studies with a model aldehyde (benzaldehyde) have given very promising results: the desired stereochemistry of all four stereocenters of the target molecule has been achieved with high diastereoselection. The stereochemistry of three key intermediates and the target segment has been confirmed by X-ray crystallography.

Tuning protein adsorption on graphene surfaces via laser-induced oxidation

An approach for controlled protein immobilization on laser-induced two-photon (2P) oxidation patterned graphene oxide (GO) surfaces is described. Selected proteins, horseradish peroxidase (HRP) and biotinylated bovine serum albumin (b-BSA) were successfully immobilized on oxidized graphene surfaces, via non-covalent interactions, by immersion of graphene-coated microchips in the protein solution. The effects of laser pulse energy, irradiation time, protein concentration and duration of incubation on the topography of immobilized proteins and consequent defects upon the lattice of graphene were systemically studied by atomic force microscopy (AFM) and Raman spectroscopy. AFM and fluorescence…

N-methyl-1,2-dihydro-2-benzoylmethylenequinolines: configurational dissimilarity with unmethylated congeners

Abstract Twelve 1-methyl-1,2-dihydro-2-benzoylmethylenequinolines have been synthesized and their structures elucidated by 1 H, 13 C and 15 N NMR, UV–Vis and X-ray methods. The results unambiguously show that these compounds and the corresponding 1,2-dihydro-2-benzoylmethylenequinolines both in crystalline and in solution state are the Z and E isomers, respectively. Comparison of the X-ray structures reveal that ( Z )-1,2-dihydro-2-benzoyl-methylenequinolines are less twisted as compared to their 1-methyl derivatives. This difference is caused by formation of the quasi-aromatic six-membered ring stabilized by an intramolecular hydrogen bond in unmethylated congeners, prevented by N -methyla…

Nanoscale probing of the supramolecular assembly in a two‐component gel by near‐field infrared spectroscopy

The design of soft biomaterials requires a deep understanding of molecular self-assembly. We introduce here a nanoscale infrared (IR) spectroscopy study of a two-component supramolecular gel to assess the system´s heterogeneity and supramolecular assembly. In contrast to far-field IR spectroscopy, near-field IR spectroscopy revealed differences in the secondary structures of the gelator molecules and non-covalent interactions at three distinct nano-locations of the gel network. A β-sheet arrangement is dominant in single and parallel fibres with a small proportion of an α-helix present, while the molecular assembly derives from strong hydrogen bonding. However, at the crossing point of two …

Polyether-bridged cyclophanes incorporating bisphenol A units as neutral receptors for quats: synthesis, molecular structure and binding properties

Two novel neutral polyoxyethylene bridged cyclophanes (2a and 2b) incorporating bisphenol A units were synthesized and characterized by means of x-ray crystal structure determination. The binding properties of 2a and 2b toward tetramethylammonium, N-methylpyridinium, and acetylcholine cations were evaluated by means of 1H NMR spectroscopy. Consistent with indications provided by the molecular structure, the cavity in the basket-like cyclophanes is large enough to accommodate the given guest cations conveniently. Circumstantial evidence was obtained that 1,1,2,2-tetrachloroethane is too large to enter the cavity of the smaller cyclophane 2a, but can be included in the cavity of the larger cy…

Nondestructive Size Determination of Thiol-Stabilized Gold Nanoclusters in Solution by Diffusion Ordered NMR Spectroscopy

Diffusion ordered NMR spectroscopy (DOSY) was used as an analytical tool to estimate the size of thiol-stabilized gold nanoclusters in solution, namely, phenylethanethiol (PET) stabilized Au25(PET)18, Au38(PET)24, and Au144(PET)60. This was achieved by determining the diffusion coefficient and hydrodynamic radius from solution samples that were confirmed to be monodispersed by electrospray ionization mass spectrometry. The average cluster diameters obtained by this technique were estimated to be 1.7, 2.2, and 3.1 nm for the Au25(PET)18, Au38(PET)24, and Au144(PET)60 nanoclusters, respectively, which were shown to agree well with the average diameters of the corresponding single crystal or t…

A perspective to resorcinarene crowns

In this report, we have summarized different synthesis methods of the resorcinarene crowns, discussed their structural and complexation properties together with the possible application aspects. peerReviewed

Predominance of 2-arylhydrazones of 1,3-diphenylpropane-1,2,3-trione over its proton-transfer products

2-Phenylhydrazones of 1,3-diphenyl-1,2,3-trione are the dominant tautomeric form detected in chloroform solution by 15N NMR chemical shifts. The substituent in the phenylhydrazone moiety does not affect this tautomeric preference. The substituent effect is transmitted effectively only to the hydrazone nitrogen and hydrogen atoms. Ab initio calculations show that the ketohydrazone tautomer is really very much favoured over its proton-transfer products in chloroform solution. The same tautomer was also detected in the crystal state by X-ray crystallography. Copyright © 2001 John Wiley & Sons, Ltd.

Conformational properties and folding analysis of a series of seven oligoamide foldamers

33 crystal structures (11 unsolvated and 22 solvates) of a series of seven oligoamide foldamers were analysed. The crystal structures revealed that despite the structural and environmental differences the series of foldamers prefer only two general conformations, a protohelical @-conformation and a sigmoidal S-conformation. Both conformations also have preferred crystal packing motifs and solvate forming tendencies. Hydrogen bonding was found to be the most decisive factor in conformational preference, but steric properties, the type of the peripheral substituents, as well as solvent and aromatic interactions were also found to have an effect on the conformational details and crystal form. …

Diastereoselective formation of highly functionalised α-substituted amino acid derivatives via aldol addition

Abstract Highly diastereoselective aldol additions of (2 R ,4 S )-3- tert -butyl 4-methyl 2- tert -butyloxazolidine-3,4-dicarboxylate ( 1 ) are reported. The utility of the highly substituted oxazolidines of type 1 for diastereoselective α-addition of the fully protected amino acid l -serine with achiral and chiral carbonyl compounds is demonstrated and the relative and absolute configuration of the aldol products are discussed on the basis of NOESY data and solid state structures of selected examples. The aldol products represent highly useful intermediates in the syntheses of sphingosine-related metabolites.

Resorcinarene Bis-Thiacrowns: Prospective Host Molecules for Silver Encapsulation

Mixed-donor atom tetramethoxy resorcinarene bis-thiacrown hosts, in which the crown unit contains both hard oxygen and soft sulfur donor atoms, were synthesized for soft metal cation binding. The binding properties were investigated both in solution and in the solid state by NMR spectroscopy and X-ray crystallography. It was found that the resorcinarene bis-thiacrowns were able to complex silver cations with remarkable affinity forming readily 1:2 host–guest complexes in solution. The solid state structures also revealed that the bis-thiacrowns form silver complexes in an unanticipated endo- and exo-cavity fashion within the same host molecule. Both the solution and solid state studies indi…

Complexation of Small Molecules by Open-Ended Resorcarene Hosts

[structure: see text] Sterically hindered tetraaminomethylated resorcarenes form inclusion complexes in CDCl(3) with acetonitrile and acetaldehyde, which are kinetically stable on the NMR time scale at 233 K.

Crystal Structures and Density Functional Theory Calculations of o-and p-Nitroaniline Derivatives: Combined Effect of Hydrogen Bonding and aromatic interactions on dimerization energy

The interplay of strong and weak hydrogen bonds, dipole–dipole interactions, and aromatic interactions of o- and p-nitroaniline derivatives was studied by combining crystal structure analysis and density functional theory (DFT) calculations. Crystal structures of four 2-nitroaniline derivatives, 2-((2-nitrophenyl)amino)ethyl methanesulfonate (1A), 2-((2-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (2A), N,N′-((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(2-nitroaniline) (3A), and N-(2-chloroethyl)-2-nitroaniline (4A), and crystal structures of three 4-nitroaniline derivatives, 2-((4-nitrophenyl)amino)ethyl methanesulfonate (1B), 2-((4-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (…

Self‐Assembly and Characterisation of Grid‐Type Iron( II ), Cobalt( II ) and Zinc( II ) Complexes

The reaction of the ligands 5 and 6, containing two tridentate binding units, with iron(II), cobalt(II) and zinc(II) leads to the self-assembly of supramolecular architectures of [2 × 2] grid type containing four ions in octahedral coordination sites. The grid-type structures have been assigned on the basis of the spectroscopic data in solution, and confirmed in the solid state in the case of complexes 6b and 6c by X-ray crystallography. The latter study revealed that each metal ion is situated in a distorted octahedral coordination environment comprising two N,N,O ligand donor sets. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

NMR, X-Ray and MS Investigations of Ethyl 2-Aroyl-and Ethyl 2-Arylcarbamoyl-4,5- dimethyl-1,2,3,6-tetrahydropyridazine-1- carboxylates: Flexible Multidentate Ligands

The 1H and 13C NMR spectral assignments of ethyl 2-aroyl-4,5-dimethyl-1,2,3,6-tetrahydropyridazine-1-carboxylates (1a-1h) and ethyl 2-arylcarbamoyl-4,5-dimethyl-1,2,3,6-tetrahydropyridazine-1-carboxylates (2a-2k) are given based on DQF COSY, 1H,13C HMQC and 1H,13C HMBC-measurements; the dynamics of the tetrahydropyridazine ring has been studied by 1H, 1H EXSY-technique and the structure of one congener (4′-methylphenyl-derivative, 2a) has been confirmed by X-ray structure analysis.

Reactions of Carbonyl Compounds in Basic Solutions. Part 351: The Alkaline Hydrolysis and Reactivity – Structure – Spectra Correlations of (Z)-4-(Substituted Benzylidene)-2-Phenyl-4H-Oxazol-5-Ones

The kinetics of the alkaline hydrolysis and the configuration, conformation and electronic structure were studied using IR, NMR spectroscopy, X-ray analysis and AM1 theoretical calculations for a series of (Z)-4-(substituted benzylidene)-2-phenyl-4H-oxazol-5-ones (1) and compared with analogous results reported for (E)-4-benzylidene-2-phenyl-4H-furan-5-ones (5) and related compounds.

(1Z,3Z)-1,4-Di(pyridin-2-yl)buta-1,3-diene-2,3-diol:  The Planar Highly Conjugated Symmetrical Enediol with Multiple Intramolecular Hydrogen Bonds

1H, (13)C, and (15)N NMR spectral data show that in chloroform solution (1Z,3Z)-1,4-di(pyridin-2-yl)buta-1,3-diene-2,3-diol, OO, is in ca. 9:1 equilibrium with (3Z)-3-hydroxy-1,4-di(pyridin-2-yl)but-3-en-2-one, OK, while no 1,4-di(pyridin-2-yl)-2,3-butanedione, KK, was detected. The species present in the tautomeric mixture were identified by comparing their experimental chemical shifts with those known for similar compounds as well as with the theoretically calculated (GIAO-HF/DFT) values. Ab initio calculations show that OK and especially the highly conjugated OO forms are preferred in the tautomeric mixtures both in vacuo and in chloroform solution. Comparison of experimental (Arrhenius)…

Recognition of alkali metal halide contact ion pairs by uranyl-salophen receptors bearing aromatic sidearms. The role of cation-pi interactions.

Hard anions have long been known to bind strongly to the uranium of uranyl-salophen complexes. Upon functionalization of the salophen framework with one or two benzyloxy substituents, efficient ditopic receptors for alkali metal ions are obtained. The solid-state structures of complexes formed by the two-armed receptor 1 with CsF and with the chlorides of K+, Rb+, and Cs+ reported here reveal the existence of dimeric supramolecular assemblies in which two receptor units assemble into capsules fully enclosing (MX)2 ion quartets. In addition to the strong coordinative binding of the anion to the uranyl center and to electrostatic cation-anion interactions, stabilizing interactions arise from …

The Missing Member of the Partially O-Alkylated Resorcinarene Family: Synthesis and Conformation of Methyl Tetramethoxy Resorcinarene

An improved Lewis acid catalyzed synthesis method for methyl tetramethoxy resorcinarene is described, which produced the missing lower rim methyl derivative of this partially O-alkylated resorcinarene family. Structural characterization by means of variable temperature NMR experiments and single crystal X-ray diffraction studies furthermore revealed that the resorcinarene core adopts different conformations in the solid state and in solution. peerReviewed

The complexation of tetraphenylborate with organic N-heteroaromatic cations

Complexation studies of eleven N-heteroaromatic cations with tetraphenylborate are reported. Tetraphenylborate forms complexes with five cations and reacts to form Lewis-base boranes with six cations. The complexes and the displacement reaction products were characterised by 1H NMR spectroscopy, elemental analysis and crystallographic methods. In the complexes C–H⋯π or N–H⋯π hydrogen bonds are the principal intermolecular interactions. The stability constants for the complexes are determined by 1H NMR titration in acetonitrile–methanol (1 ∶ 1) solution. Crystal structures of four of the complexes and three of the Lewis-base triphenylborane products are reported.

Solvent driven formation of silver embedded resorcinarene nanorods

Silver complexes of resorcinarene bis-crown-5 were observed to arrange into nanorods of 2.4 nm in diameter. The left- and right-handed isomers of the inherently chiral resorcinarene host are separated into their own entity in the self-assembly process with the periphery of the nanorods consisting of silver cations included in the cavity.

Crystal Structures and Density Functional Theory Calculations of o-and p-Nitroaniline Derivatives: Combined Effect of Hydrogen Bonding and aromatic interactions on dimerization energy

The interplay of strong and weak hydrogen bonds, dipole–dipole interactions, and aromatic interactions of o- and p-nitroaniline derivatives was studied by combining crystal structure analysis and density functional theory (DFT) calculations. Crystal structures of four 2-nitroaniline derivatives, 2-((2-nitrophenyl)amino)ethyl methanesulfonate (1A), 2-((2-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (2A), N,N′-((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(2-nitroaniline) (3A), and N-(2-chloroethyl)-2-nitroaniline (4A), and crystal structures of three 4-nitroaniline derivatives, 2-((4-nitrophenyl)amino)ethyl methanesulfonate (1B), 2-((4-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (…

Corrigendum to “Comparison of epimeric methyl lithocholate and methyl iso-lithocholate molecules: Single crystal X-ray structure of methyl lithocholate, ab initio HF/6-31G* optimized structures and experimental and calculated DFT/B3LYP 13C NMR chemical shifts” [J. Molstruc. 649 (2003) 207–218]

Solid state halogen bonded networks vs. dynamic assemblies in solution: explaining N⋯X interactions of multivalent building blocks

Tetrapyridine functionalized resorcinarene macrocycles were used as multivalent building blocks for the construction of halogen bonded networks with aryl halide linkers. In the solid state, resorcinarene macrocycles and aryl halide linker molecules assembled into interpenetrated, multidimensional halogen bonded networks with porous structure caused by the 3D block scaffold of the resorcinarenes. 19F NMR spectroscopy proved halogen bond formation also in solution, as either upfield or downfield shifts were observed depending on the bivalent or monovalent halogen bond binding mode. The binding mode in solution was explained by density functional theory computations. peerReviewed

Ethyl Pyrogallarene and Pyrogallarene: Synthesis, Structural Analysis and Derivatization

In the acid-catalyzed synthesis of ethyl pyrogall[4]arene, a novel hexamer, ethyl pyrogall[6] arene, is obtained as a readily isolable minor product. Pyrogall[6]arene can be isolated from the reaction mixture in three different ways yielding the hexamer in different forms and stabilities. Crystallization from DMSO and then recrystallization from acetone gives a stable crystalline solid, recrystallization directly from acetone yields an unstable white powder, while direct recrystallization from THF gives a stable white powder. Both pyrogall[4]arene and pyrogall[6]arene crystallize readily with DMSO filling the voids in the crystal lattice. Co-crystallization studies of the hexamer isolated b…

Twisting of the resorcinarene core due to solvent effects upon crystallization

The effect of the crystallization conditions on the conformation of the tetramethoxy resorcinarene skeleton was investigated in acetone solutions, to which was added a second component (less favorable solvent or salt) to promote crystallization. The resorcinarene core was found to adopt three different conformations: crown (I), a pinched crown (II) and a twisted pinched crown (III). In addition, the flexibility of the resorcinarene core was compared with a tetramethoxy resorcinarene derivative, resorcinarene bis-crown, which is in a fixed boat conformation.

ChemInform Abstract: Calixcrowns : Synthesis and Properties

The synthesis and properties of calix[n]crowns (n = 4–8), calix[n]biscrowns and their related compounds, resorcinarene crowns, have been discussed and reviewed. These macrocycles exhibit remarkable ionophoric properties toward alkali and alkaline earth metal cations, as well as, to tertiary amines. The selectivity and efficiency of calixcrowns in binding cations have been attributed to their structural features, which include substituent effects and size of the crown ether moiety and, conformation of the parent calixarene.

Ammonium ion mediated resorcarene capsules: ESI-FTICRMS study on gas-phase structure and ammonium ion affinity of tetraethyl resorcarene and its per-methylated derivative

AbstractThe ammonium ion binding affinities of tetraethyl resorcarene (1) and its per-methylated derivative (2) were studied by electrospray ionization Fourier transform ion cyclotron resonance (ESI-FTICR) mass spectrometry. Ten different ammonium ions were tested as guests for the resorcarenes. A strong tendency for complex formation was observed with all ammonium ions of size and charge distribution suitable for noncovalent interactions with the cavities of the resorcarene hosts 1 and 2. Although differences in ammonium ion affinities were observed between 1 and 2 due to the dissimilar conformations, the overall tendency was that increase in the degree of substitution and the length of ca…

Synthesis and Characterization of theO-Alkylation Products of Resorcinarene

O-Substitution reactions of tetramethoxyresorcinarene with alkyl halides produced a variety of partially O-alkylated resorcinarene derivatives with terminal alkyne functionality. The degree of alkylation was affected by the reactivity of the alkylating halide used. NMR spectroscopy proved to be an ideal tool for analyzing the complex reaction mixtures and the isolated products based on the symmetry and degree of alkylation of the resorcinarene derivatives. Single-crystal X-ray diffraction studies furthermore showed diversity in the self-assembly of the various O-alkylation products that was greatly affected by the degree of alkylation, as well as the nature of the alkyne moiety.

Covalently linked multi-calixarenes

Abstract ipso-Nitration of t-butyl calix[4]arene tetraethers and subsequent hydrogenation provides an easy access to monoamino calix[4]arenes. Reaction with di- and triacid chlorides leads to various double- and triple-calix[4]arenes. With tetraacid chlorides derived from calix[4]arenes in the cone- or 1,3-alternate-conformations penta-calix[4]arenes are available as molecularly uniform species, which may be regarded as the first generation of calix[4]arene based dendrimers. The structure of the mononitro tetraester derivative, which may serve as a general building block has been confirmed by single crystal X-ray analysis.

Encapsulation of diquats by resorcinarenes: a novel staggered anion–solvent mediated hydrogen bonded capsule

Crystallisation studies of ethyl resorcinarene with diquats 2b and 3a (1,4-dimethyl-1,4-diazoniabicyclo[2.2.2]octane dibromide and 1,4-diazoniabicyclo[2.2.2]octane dichloride, respectively) resulted in hydrogen bonded molecular capsules in which the cations are encapsulated in between the cavities of two resorcinarene molecules and anions are located in the middle of the lower rim ethyl chains.

Derivatisation of Pyrogallarenes

Derivatisation of upper-rim hydroxy groups of pyrogallarenes produced completely acylated and tosylated pyrogallarene derivatives. Mesitylation of pyrogallarene, however, resulted in a regioselective derivatisation of hydroxy groups, i.e. eight OH groups out of 12 were mesitylated. Crystal structures of the synthesised pyrogallarene derivatives indicate that completely substituted pyrogallarenes exist in a distorted crown conformation despite of the lack of stabilising intramolecular hydrogen bonds. In contrast, the partially substituted pyrogallarene adopts a boat conformation and has an open cavity for the inclusion of small guest molecules. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinh…

Solvent Exchange in Thermally Stable Resorcinarene Nanotubes

The assembly of C-methyl resorcinarene into a tubular supramolecular solid-state structure, its thermal stability, and its hosting properties are reported. Careful control of the crystallisation conditions of C-methyl resorcinarene and 1,4-dimethyl-1,4-diazoniabicyclo[2.2.2]octane (1,4-dimethyl DABCO) dibromide leads to a formation of two crystallographically different, but structurally very similar, solid-state nanotube structures. These structures undergo a remarkable variety of supramolecular interactions, which lead to the formation of 0.5 nm diameter nonpolar tubes through the crystal lattice. The formation of these tubes is templated by suitably sized small alcohols, namely, n-propano…

Polyhydroxylated indolizidine alkaloids-synthesis of dideoxycastanospermine

The key transformation developed in this work is the anti-Kishi selective dihydroxylation, which proceeds by way of intramolecular participation of the nitrogen protecting group to furnish the desired stereochemistry required for castanospermine like structures. In this paper, we completed a first syn-thesis of a novel dideoxycastanospermine 6. Peer reviewed

Oligoamide Foldamers as Helical Chloride Receptors-the Influence of Electron-Withdrawing Substituents on Anion-Binding Interactions.

The anion-binding properties of three closely related oligoamide foldamers were studied using NMR spectroscopy, isothermal titration calorimetry and mass spectrometry, as well as DFT calculations. The 1 H NMR spectra of the foldamers in [D6 ]acetone solution revealed partial preorganization by intramolecular hydrogen bonding, which creates a suitable cavity for anion binding. The limited size of the cavity, however, enabled efficient binding by the inner amide protons only for the chloride anion resulting in the formation of a thermodynamically stable 1:1 complex. All 1:1 chloride complexes displayed a significant favourable contribution of the entropy term. Most likely, this is due to the …

Noncovalentπ⋅⋅⋅π-Stacked Exo-Functional Nanotubes: Subtle Control of Resorcinarene Self-Assembly

Resorcinarene bis-crown silver complexes and their application as antibacterial Langmuir-Blodgett films

Silver complexes of a cation binding supramolecular host, resorcinarene bis-crown (CNBC5) with propyl, nonyl, decyl and undecyl alkyl chains were investigated by NMR titration, picrate extraction and single crystal X-ray diffraction. Binding studies showed that both 1 : 1 and 1 : 2 (host-Ag(+)) complexes are present in solution with only a slight effect of the lower rim alkyl chain length on the binding constants (log K 4.0-4.2 for 1 : 2 complexes). Solid state complexes of the resorcinarene bis-crowns bearing either C(3) or C(11) chains were obtained. Single crystal X-ray analyses showed that both derivatives bind silver ions by metal-arene and Ag···O coordination from the crown ether brid…

Cation binding resorcinarene bis-crowns: the effect of lower rim alkyl chain length on crystal packing and solid lipid nanoparticles

A group of seven resorcinarene bis-crown ethers (CNBC5) with two polyether bridges at the upper rim and either propyl, butyl, pentyl, heptyl, nonyl, decyl or undecyl groups at the lower rim were synthesized and their binding properties with Cs+ were investigated by NMR titration. The bis-crowns form 1:2 complexes with Cs+ with binding constants of logK 4–5. Crystal structures of bis-crowns and their Cs+ and K+ complexes were studied and different packing motifs were found depending on the alkyl chain length. Short ethyl, propyl and butyl alkyl chains gave a layer or pillar packing where the polar and non-polar regions cannot be distinguished, whereas longer pentyl and decyl chains formed bi…

Synthesis, characterization, and complexation of tetraarylborates with aromatic cations and their use in chemical sensors.

Five aromatic borate anions, namely tetrakis(4-phenoxyphenyl)borate (1), tetrakis(biphenyl)borate (2), tetrakis(2-naphthyl)borate (3), tetrakis(4-phenylphenol)borate (4), and tetrakis(4-phenoxy)borate (5), have been prepared and tested as ion-recognition sites in chemical sensors for certain aromatic cations and metal ions. To gain further insight into the complexation of the cations, some complexes have been prepared and structurally characterized. The complexation behavior of 1 and 2 towards N-methylpyridinium (6), 1-ethyl-4-(methoxycarbonyl)pyridinium (7), tropylium (8), imidazolium (9), and 1-methylimidazolium (10) cations has been studied, and the stability constants of the complexes o…

Supramolecular chirality and symmetry breaking of fluoride complexes of achiral foldamers

Aromatic oligoamide foldamers containing a central pyridine-2,6-dicarbonyl motif are partially preorganized to favor the binding of fluoride anions. In the solid state, the foldamer-fluoride complexes form achiral, polar and chiral crystal structures depending on the chemical structure of the foldamer. One of the six foldamers studied here, a C2v symmetrical foldamer (1), formed repeatedly chiral crystal structures when crystallized with tetra-butylammonium fluoride, showing supramolecular bulk chirality and symmetry breaking in crystallization.

Polymorphism and versatile solvate formation of thiophanate-methyl

The polymorphism of a fungicide, thiophanate-methyl (TM), was investigated with conventional solvent screening methods. Two polymorphs, the thermodynamically most stable form I and the less stable form II, were found. TM was also found to crystallize as a plethora of different solvates which produced mostly form II upon desolvation. The structures of form I and form II and the fourteen discovered solvates were solved by single crystal X-ray diffraction. The most stable forms were further characterized by powder diffraction, thermoanalytical (TG/DTA, DSC and thermomicroscopy) and spectroscopic (IR, Raman, ¹³C CP/MAS NMR) methods. peerReviewed

Inverted molecular cups: 1-D and 2-D Ag(I) coordination polymers from resorcinarene bis-thiacrowns

Resorcinarene bis-thiacrown hosts 1–3 were prepared and crystallized with silver trifluoroacetate yielding one and two dimensional Ag coordination polymers. The complexation of silver in exo-cavity fashion folds the thiacrown bridges inwards transforming the resorcinarene hosts into inverted molecular cups. The silver cations were coordinated to the resorcinarene ligands and trifluoroacetate anions, which act as monodentate or bidendate bridging ligands between the metal ions. Argentophilic Ag···Ag (2.93–3.38 Å) interactions supported by two bridging carboxylate anions were found in two of the structures, whereas longer Ag···Ag distances were observed if only one anion connected the silver …

Structural characterization of β-2′-pyridylaminocrotonoyl-2-pyridylamide by ESI-MS, NMR, single crystal X-ray analysis and ab initio methods

Abstract In contradiction with earlier reports 1H, 13C and 15N NMR spectra show that β-2′-pyridylaminocrotonoyl-2-pyridylamide is the only form present in chloroform solution. According to the X-ray data the same tautomer exists also in the crystal state. The studied amide has a dimeric form where the monomer molecules are held together by two intermolecular hydrogen bonds. The NMR spectral data show that there is also an intramolecular hydrogen bond in each monomer subunit. The dilution experiments and variable-temperature 1H NMR runs show that β-2′-pyridylaminocrotonoyl-2-pyridylamide tends to form the dimers also in chloroform solution at higher concentrations. The ESI-TOF MS measurement…

Synthesis and characterization of new aromatic tweezers and complex formation with tropylium ion in 1,2-dichloroethane

A series of benzene and pyridine tweezers bearing phenyl, naphthyl and anthryl receptor units was prepared and characterized. The x-ray crystal structure of the 1,3-bis(9-methanolanthracene)methylbenzene ligand (5) is reported. UV–visible and NMR spectroscopy were used to investigate the host–guest chemistry of the new ligands in complexation with tropylium tetrafluoroborate as a model aromatic cationic guest in 1,2-dichloroethane. The appearance of coloured charge-transfer absorption bands demonstrates the complex formation with a tropylium ion. The enlargement of aryl receptor size from phenyl and naphthyl to anthryl increases the stability of complexes. Electron donor–acceptor interactio…

A new potential toxaphene congener: synthesis, GC/EI-MS study, crystal structure, NMR analysis, and ab initio calculations of 3-endo,5-endo-dichloro-7,7-bis-chloromethyl-4-dichloromethyl-tricyclo[2.2.1.02,6]heptane

Abstract A new potential toxaphene congener 3- endo ,5- endo -dichloro-7,7-bis-chloromethyl-4-dichloromethyl-tricyclo[2.2.1.0 2,6 ]heptane 2 has been isolated from reaction mixture obtained by the chlorination of 2- exo ,10,10-trichlorobornane 1 . The X-ray structural analysis of 2 revealed an unusual tricyclic structure, where the two chlorine atoms occupying endo -positions are in close spatial proximity with each other and near to the neighbouring CHCl 2 group. Further, it revealed that the symmetry of the molecule is distorted. The 1 H and 13 C NMR spectra of 2 have been assigned by means of 1 H, 1 H d ouble- q uantum f iltered co rrelation s pectroscop y (DQF COSY), PFG 1 H, 13 C HMQC …

Comparative NMR and IR spectral, X-ray structural and theoretical studies of eight 6-arylidenedibenzo[b,e]thiepin-11-one-5,5-dioxides

Abstract Eight 6-arylidenedibenzo[b,e]thiepin-11-one-5,5-dioxides are characterized by NMR and IR spectroscopy. Single crystal X-ray structures for three congeners are reported. In addition, the transmission of substituent effects in conjugated double bond system of 6-arylidenedibenzo[b,e]thiepin-11-one-5,5-dioxide framework has been evaluated by calculating the correlations between selected 13C NMR chemical shifts and IR stretching wave numbers and Hammett constants of the substituents locating in the phenyl ring of the arylidene moiety.

The Effect of Halogen Bonding on the Packing of Bromine Substituted Pyridine and Benzyl Functionalized Resorcinarene Tetrapodands in the Solid State

The synthesis and characterization of new bromine-substituted pyridine and benzyl functionalized tetramethoxy resorcinarene tetrapodands are described and their solid-state structural properties and interactions were studied by single crystal X-ray crystallography. Three different crystal structures were obtained for the pyridine derivative and one for the benzyl derivative, which revealed that the interactions of the bromine substituent have an explicit effect on the crystal packing of the resorcinarene molecules. One of the structures obtained had very interesting halogen–halogen interactions with the same geometry as is generally found for compounds used in nonlinear optical studies. pee…

Complexation of planar, organic, five-membered cations with crown ethers

Complexation of six aromatic, nitrogen-containing cations with various crown ethers has been studied using 1H NMR, mass spectrometric and crystallographic methods. Hydrogen bonding appears to be the most important interaction in complexation, but minor effects such as π-stacking or cation–π interactions have also been observed. The stability constants of five different imidazolium perchlorate ·crown ether complexes and five other similar cation·DB18C6 complexes were determined by 1H NMR titration in acetonitrile solution. The stability of these complexes in solution and in the gas phase is discussed. The crystal structures of seven complexes were determined in order to study complexation in…

Regioselective acylation of aminoresorcinarenes

Abstract The acid catalyzed hydrolytic cleavage of the oxazine rings in the readily available tetraoxazine derivatives of resorcinarenes results in tetraaminoresorcinarenes. A similar process applied to C2-symmetrical bisoxazine resorcinarene tetratosylates affords C2v-symmetrical resorcinarenediamines. The mild acylation of these resorcinareneamines with BOC-anhydride or para-nitrophenyl ester proceeds selectively at the nitrogen atoms without affecting the hydroxyl groups. Most of the resulting resorcinareneamides are thus obtained in preparative yields and can be easily purified by simple crystallizations. In the crystalline state the compounds obtained are found to bind chloride anions …

Syntheses with organoboranes. Part 14: Enolization–aldolization of conjugated cyclohexenones via dienolborinates

Abstract Enolization of cyclohex-2-enone ( 1 ), 3-methyl- ( 2 ), 3,5-dimethyl- ( 3 ), 3,5,5-trimethyl- ( 4 ), and 3,4,5,5-tetramethylcyclohex-2-enone ( 5 ) with chlorodicyclohexylborane proceeds by deprotonation at the 6-position. Aldolization of the dienolborinates with benzaldehyde, and acetaldehyde, provides the corresponding anti aldols with 87–95% selectivity. Ketones 4 and 5 undergo competitive deprotonation at the 3-methyl group and aldolization at the 2-position. In contrast, lithium dienolates derived from 4 and 5 gave syn aldols with 95% selectivity.

Conformational polymorphism and amphiphilic properties of resorcinarene octapodands

o-Nitroaniline functionalized resorcinarene octapodands 1-5 with pendant methyl, ethyl, pentyl, nonyl or 1-decenyl groups, respectively, were synthesized and their structural properties investigated using X-ray crystallography and NMR spectroscopy. The upper rim of each podand is identical containing flexible side arms, in which rotation around the -OCH(2)CH(2)N- linkers create excellent possibilities for polymorphism. Two conformational polymorphs of acetone solvate of 2 were identified containing different side arm orientation and crystal packing. Compound 1 crystallized from acetone and nitromethane yielding two pseudopolymorphs with different packing motifs. The longer alkyl chains of 3…

Co-crystals of an agrochemical active – A pyridine-amine synthon for a thioamide group

Five novel co-crystals of thiophanate-ethyl (TE), an agrochemical active, with di(2-pyridyl)ketone (1), 2-benzoylpyridine (2), 3-benzoylpyridine (3), 4-phenylpyridine (4) and biphenyl (5) were found and crystal structures of four of them (TE1–TE3, TE5) solved by single crystal X-ray diffraction. Three of the co-crystals (TE1–TE3) form by way of a reliable pyridine-amine hydrogen bond synthon and one (TE5) because of close packing effects. The fifth co-crystal was identified by X-ray powder diffraction. The work demonstrates the usage of a reliable supramolecular synthon for crystal engineering, while concurrently reminds that the close packing of even very similar molecules cannot be fully …

Oligoamide Foldamers as Helical Chloride Receptors : the Influence of Electron-Withdrawing Substituents on Anion-Binding Interactions

The anion‐binding properties of three closely related oligoamide foldamers were studied using NMR spectroscopy, isothermal titration calorimetry and mass spectrometry, as well as DFT calculations. The 1H NMR spectra of the foldamers in [D6]acetone solution revealed partial preorganization by intramolecular hydrogen bonding, which creates a suitable cavity for anion binding. The limited size of the cavity, however, enabled efficient binding by the inner amide protons only for the chloride anion resulting in the formation of a thermodynamically stable 1:1 complex. All 1:1 chloride complexes displayed a significant favourable contribution of the entropy term. Most likely, this is due to the re…

Comparison of epimeric methyl lithocholate and methyl iso-lithocholate molecules: single crystal X-ray structure of methyl lithocholate, ab initio HF/6-31G* optimized structures and experimental and calculated DFT/B3LYP 13C NMR chemical shifts

Abstract 13 C NMR chemical shifts have been measured and assigned for epimeric methyl 3α/β-hydroxy-5β-cholan-24-oates (methyl lithocholate [3α-OH epimer] and methyl iso-lithocholate [3β-OH epimer]). Their molecular dynamics simulations suggest that for both epimers there exists two predominant gas phase conformations, which have been further forwarded for ab initio/HF optimizations and DFT/GIAO based 13 C NMR chemical shift calculations. Excellent linear relationships have been observed between experimental and calculated 13 C NMR chemical shifts for both epimers. For methyl lithocholate (MeLC), the other minimum energy conformation equates very well with the single crystal X-ray structure …

Tuning protein adsorption on graphene surfaces via laser-induced oxidation

An approach for controlled protein immobilization on laser-induced two-photon (2P) oxidation patterned graphene oxide (GO) surfaces is described. Selected proteins, horseradish peroxidase (HRP) and biotinylated bovine serum albumin (b-BSA) were successfully immobilized on oxidized graphene surfaces, via non-covalent interactions, by immersion of graphene-coated microchips in the protein solution. The effects of laser pulse energy, irradiation time, protein concentration and duration of incubation on the topography of immobilized proteins and consequent defects upon the lattice of graphene were systemically studied by atomic force microscopy (AFM) and Raman spectroscopy. AFM and fluorescence…

Packing incentives and a reliable N–H⋯N–pyridine synthon in co-crystallization of bipyridines with two agrochemical actives

The co-crystallization of agrochemical actives thiophanate-methyl and thiophanate-ethyl with 2,2′-bipyridine, 4,4′-bipyridine and 1,2-bis(4-pyridyl)ethane was investigated with conventional crystallization, the slurry method and liquid-assisted grinding. Co-crystals of both thiophanates with all bipyridines were found and the structures solved with single crystal X-ray diffraction. Whereas the 2,2′-bipyridine co-crystals seem to form because of a combination of weak interactions, and in the case of the thiophanate-methyl, partly because of close packing incentives, the 4,4′-bipyridine and 1,2-bis(4-pyridyl)ethane co-crystals form mainly because of a favourable N–H···N–pyridine hydrogen bond…

Folding Patterns in a Family of Oligoamide Foldamers

A series of small, unsymmetrical pyridine-2,6-dicarboxylamide oligoamide foldamers with varying lengths and substituents at the end groups were synthetized to study their conformational properties and folding patterns. The @-type folding pattern resembled the oxyanion-hole motifs of enzymes, but several alternative folding patterns could also be characterized. Computational studies revealed several alternative conformers of nearly equal stability. These folding patterns differed from each other in their intramolecular hydrogen-bonding patterns and aryl-aryl interactions. In the solid state, the foldamers adopted either the globular @-type fold or the more extended S-type conformers, which w…

Solid lipid nanoparticles from amphiphilic calixpyrroles

Abstract Hypothesis Macrocyclic amphiphiles form interesting self-assembling structures, including solid lipid nanoparticles, which have potential applications in drug encapsulation. Aryl-extended calixpyrroles, which act as anion binding hosts, are expected to form solid lipid nanoparticles, even though the alkyl chains have unusual perpendicular geometry with respect to the hydrophilic head group. The preparation conditions and the alkyl chain length should affect the size and stability of the particles. Experiments Solid lipid nanoparticles of two aryl-extended calixpyrroles with resorcinol walls and either meso-dodecyl or meso-methyl alkyl chains were compared. Ethanolic solutions of th…

An Extraction-Based Assay for Neutral Anionophores: The Measurement of High Binding Constants to Steroidal Receptors in a Nonpolar Solvent

The extraction-based proto- col for measuring binding constants, developed by Cram and co-workers, has been extended for use with anionic substrates. The method is especially useful for high-affinity receptors, allow- ing very high binding constants to be measured in nonpolar solvents. Distri- bution constants Kd between chloroform and water have been obtained for tet- raethylammonium chloride and bro- mide, thus calibrating the method for these two substrates. Application to steroidal podands 5 ± 9 has confirmed the ability of electron-withdrawing groups to enhance hydrogen-bond do- nor capabilities. Binding constants of 3 10 71 have been measured for the most powerful receptor 7. An X-ray…

The Effect of Halogen Bonding on the Packing of Bromine Substituted Pyridine and Benzyl Functionalized Resorcinarene Tetrapodands in the Solid State

The synthesis and characterization of new bromine-substituted pyridine and benzyl functionalized tetramethoxy resorcinarene tetrapodands are described and their solid-state structural properties and interactions were studied by single crystal X-ray crystallography. Three different crystal structures were obtained for the pyridine derivative and one for the benzyl derivative, which revealed that the interactions of the bromine substituent have an explicit effect on the crystal packing of the resorcinarene molecules. One of the structures obtained had very interesting halogen–halogen interactions with the same geometry as is generally found for compounds used in nonlinear optical studies.

Pyrogallarenes as alkali metal receptors: the role of cation-pi interactions in complexation.

Crystallization studies of C-methyl pyrogallarene with potassium, rubidium and caesium bromides or chlorides resulted in a hydrogen bonded molecular cage in which the alkali metal cations are eta6 coordinated to aromatic rings via strong cation-pi interactions.

Novel Tetramethoxy Resorcinarene Bis-Crown Ethers

The synthesis and characterization of new tetramethoxy resorcinarene bis-crown ethers BC4 and BC5 are described. The complexation properties of the compounds toward alkali metal cations were studied by 1H NMR spectroscopy and X-ray crystallography, which revealed that BC5 can accommodate two cations simultaneously inside the crown pockets formed by the crown ether bridges and the resorcinarene skeleton. [reaction: see text].

C-Methyl resorcin[4]arene packing motifs with alkyl ammonium salts: From molecular capsules to channels and tubes

A variety of packing motifs of C-methyl resorcinarene were obtained when complexed with small alkyl ammonium salts of different size and shape. Using bromide and chloride salts of the small quaternary alkyl ammonium cations, tetramethyl ammonium and dimethyldiethyl ammonium, leads to a grid-like packing of solvent mediated dimeric capsules while the use of salts of larger diquaternary cations bearing a 1,4-diazabicyclo[2.2.2]octane (DABCO) scaffold produces solvent/anion mediated chains and channels or tubular structures. The connecting interactions between resorcinarenes in each structure are hydrogen bonding and/or π⋯π interactions.

Characterization and synthesis of O- and N-tosylated N,N-bis(2-aminophenyl)isophthalamide based ligands

Abstract A synthetic strategy for the preparation of O - and N- tosylated N , N -bis(2-aminophenyl)isophthalamide based ligands is described. It was observed that selectivity in O - and N -tosylation could be achieved by performing the reaction at low temperatures in the presence of an appropriate base. The obtained O - and N -tosylated products were characterized by means of NMR and mass spectroscopy, and X-ray crystallography.

Selenium Imides:  77Se NMR Investigations of the SeCl2−tBuNH2 Reaction and X-ray Structures of Se3(NtBu)3, tBuNSe(μ-NtBu)2SO2, and tBuNSe(μ-NtBu)2SeO

The reaction of SeCl2 with tert-butylamine in various molar ratios in THF at −78 °C has been investigated by 77Se NMR spectroscopy. In addition to the known Se−N heterocycles Se6(NtBu)2 (1) and Se9(NtBu)6 (2), the acyclic imidoselenium(II) dichlorides ClSe[N(tBu)Se]nCl (4, n = 1; 5, n = 2) and two new cyclic selenium imides [Se3(NtBu)2]n (3, n = 1 or 2) and Se3(NtBu)3 (6) have been isolated and identified. An X-ray analysis shows that 6 is a six-membered ring in a chair conformation with |d(Se−N)| = 1.833 A. Crystal data:  6, trigonal, P3c1, a = 9.8660(3) A, c = 20.8427(7) A, V = 1757.0(1) A3, Z = 6. The 1H, 13C, and 77Se NMR data for 1−6 are reported, and some reassignments of earlier lite…

Complexation of C-methyl pyrogallarene with small quaternary and tertiary alkyl ammonium cations

Complexation properties of pyrogallarene 1 towards small quaternary and tertiary alkyl ammonium cations were studied in gas phase, solution and in solid state. In gas phase both dimeric capsules and monomeric 1 : 1 complexes of all cations 2a+–d+ are detected but only in the case of 2a+ is the abundance of the capsule form higher than the monomeric 1 : 1 complex. A similar trend is observed in NMR experiments, which reveal a favourable dimeric complex for 2a+ and a weaker dimeric complex for 2b+ but only monomeric complexes for 2c+ and 2d+. Also in solid state, 2a+ and 2b+ form capsules when crystallized from MeOH while 2c+ and 2d+ form dimeric 1 : 1 complexes. As a reference, hetero-confor…

ChemInform Abstract: A Perspective to Resorcinarene Crowns

Diversity at the nanoscale : laser-oxidation of single-layer graphene affects Fmoc-phenylalanine surface-mediated self-assembly

We report the effects of a laser-oxidized single layer graphene (SLG) surface on the self-assembly of amphiphilic gelator N-fluorenylmethoxycarbonyl-L-phenylalanine (Fmoc-Phe) towards an gel–SLG interface. Laser oxidation modulates the levels of hydrophobicity/hydrophilicity on the SLG surface. Atomic force, scanning electron, helium ion and scattering scanning nearfield optical microscopies (AFM, SEM, HIM, s-SNOM) were employed to assess the effects of surface properties on the secondary and tertiary organization of the formed Fmoc-Phe fibres at the SLG–gel interface. S-SNOM shows sheet-like secondary structures on both hydrophobic/hydrophilic areas of SLG and helical or disordered structu…

Exploring the 2,2′-Diamino-5,5′-bipyrimidine Hydrogen-Bonding Motif: A Modular Approach to Alkoxy-Functionalized Hydrogen-Bonded Networks

The programmed self-association of 2,2’-diamino-4,4’-dialkoxy-5,5’-bipyrimidines allows for the de novo construction of alkoxy-functionalized H-bonded ribbons and sheets as evidenced by X-ray crystallographic analysis. The data provide insight into the interplay of the different structural and interactional features of the molecular components to the generation of the supramolecular assembly. Hydrophobicity of the didodecyl side chains of 4c leads to the dominance of the H-bonding factor, resulting in the formation of a fully interconnected array. These results define the utility of the of 2,2’-diamino-4,4’-dialkoxy-5,5’-bipyrimidines as a potential scaffold for the attachment of electro- o…

Alkali metal complexation properties of resorcinarene bis-crown ethers: effect of the crown ether functionality and preorganization on complexation

Abstract The synthesis and characterization of tetramethoxy resorcinarene tribenzo-bis-crown ethers, m - and p -TBBC6 , are described. The effect of the added aromatic functionality in the crown ether bridge on the alkali metal complexation properties was investigated and compared to the properties of tetramethoxy resorcinarene bis-crown-5 ( BC5 ) by means of 1 H NMR spectroscopy and X-ray crystallography. It was found that BC5 and m -TBBC6 were capable of binding alkali metal cations (K + , Rb + , and Cs + ), with the highest affinity toward Cs + cation, while no binding was observed in the case of p -TBBC6 , which confirms the significance of the complementarity and preorganization for co…

Inverted molecular cups: 1-D and 2-D Ag(I) coordination polymers from resorcinarene bis-thiacrowns

Resorcinarene bis-thiacrown hosts 1–3 were prepared and crystallized with silver trifluoroacetate yielding one and two dimensional Ag coordination polymers. The complexation of silver in exo-cavity fashion folds the thiacrown bridges inwards transforming the resorcinarene hosts into inverted molecular cups. The silver cations were coordinated to the resorcinarene ligands and trifluoroacetate anions, which act as monodentate or bidendate bridging ligands between the metal ions. Argentophilic Ag⋯Ag (2.93–3.38 A) interactions supported by two bridging carboxylate anions were found in two of the structures, whereas longer Ag⋯Ag distances were observed if only one anion connected the silver cati…

Non-Centrosymmetric Tetrameric Assemblies of Tetramethylammonium Halides with Uranyl Salophen Complexes in the Solid State

Ditopic salophen-UO(2) receptors 1-4 and 7 co-crystallize with tetramethylammonium (TMA) chloride and fluoride salts producing good quality crystals amenable for X-ray diffraction characterization. The arrangement of the receptor and salt units in the crystal lattice is such that tetrameric ball-shaped assemblies are formed, where an inner cluster of four TMA cations are surrounded by an outer shell of four UO(2)-bound anions. These elaborate architectures, which occur in all cases, regardless of a certain degree of structural modification on the receptors, lead to lattices that belong to non-centrosymmetric (NCS) space groups. Interestingly, the tetragonal symmetry of the tetrameric ball-s…

Substituent and temperature controlled tautomerism of 2-phenacylpyridine: the hydrogen bond as a configurational lock of (Z )-2-(2-hydroxy-2-phenylvinyl)pyridine

2-Phenacylpyridines substituted in the benzene ring are in equilibrium with (Z)-2-(2-hydroxy-2-phenylvinyl)pyridines when dissolved in chloroform. The substituent affects significantly the tautomeric equilibrium [the amount of the enolimine form stabilized by the intramolecular hydrogen bond is 1 and 92% for R = p-N(CH2)4 and p-NO2, respectively]. The negative logarithm of the tautomeric equilibrium constant, KT, is linearly dependent on the Hammett σ substituent constants. The dependence of KTvs. temperature is exponential in character: the more electron-withdrawing is the substituent, the more distinct is the influence of temperature. Unexpectedly, the tautomer present in the crystalline …

ChemInform Abstract: Exploring the 2,2′-Diamino-5,5′-bipyrimidine Hydrogen-Bonding Motif: A Modular Approach to Alkoxy-Functionalized Hydrogen-Bonded Networks.

The programmed self-association of 2,2’-diamino-4,4’-dialkoxy-5,5’-bipyrimidines allows for the de novo construction of alkoxy-functionalized H-bonded ribbons and sheets as evidenced by X-ray crystallographic analysis. The data provide insight into the interplay of the different structural and interactional features of the molecular components to the generation of the supramolecular assembly. Hydrophobicity of the didodecyl side chains of 4c leads to the dominance of the H-bonding factor, resulting in the formation of a fully interconnected array. These results define the utility of the of 2,2’-diamino-4,4’-dialkoxy-5,5’-bipyrimidines as a potential scaffold for the attachment of electro- o…

Specific recognition of fluoride anion using a metallamacrocycle incorporating a uranyl-salen unit

The design and synthesis of a novel fluoride receptor that uses a salen-complexed Lewis acidic uranyl center as the sole binding site is reported here. This receptor binds fluoride anions in DMSO with a high affinity constant (K > 106 M-1) and exhibits a negligible affinity (K < 10 M-1) towards otherwise effective competitors, such as acetate, phosphate and cyanide anions.

Weak interactions between resorcinarenes and diquaternary alkyl ammonium cations

The interactions of resorcin[4]arenes 1 with alkyl ammonium cations bearing a 1,4-diazabicyclo[2.2.2]octane (DABCO) scaffold (32+, 42+ and 52+) were analyzed in the solid state by X-ray crystallography, in solution by 1H NMR spectroscopy, and in the gas phase by ESI-TOF mass spectrometry. The results are complemented with AM1 calculations and compared to previous reports on complexation studies of resorcinarenes with quaternary alkyl ammonium cations. The NMR titration results indicate that there are hardly any differences in the binding of the quaternary tetramethyl ammonium cation 2+ and the diquaternary N,N’-dimethyl DABCO dication 42+. The large N,N’-dibenzyl DABCO dication 52+ has two …

Chlorodicyclopentadienyloxoniobium(V) complexes revisited: The origin of the asymmetry in the 1H- and 13C-NMR spectra, X-ray crystal structures and ab initio/HF and DFT/B3LYP calculations

Abstract 1H- and 13C-NMR spectra of chlorodicyclopentadienyloxoniobium(V) complex I and its four 1,1′-dialkyl substituted derivatives II–V have been recorded and assigned based on DQF 1H,1H-COSY and PFG 1H,13C-HMQC and HMBC experiments. Non-equivalences of all cyclopentadienyl protons and carbons in II–V (as reflected by their different 1H- and 13C-NMR chemical shifts) are explained by synchronous and out-of-phase rotations of the substituted cyclopentadienyl rings. A non-equivalence of the methyls in III (1,1′-di-isopropyl) is explained by a detailed inspection of the rotamers of the isopropyl groups. The X-ray structural data show that III and IV (1-methyl-1′-tert-butyl) crystallize in th…

Probing the Gelation Synergies and Anti-Escherichia coli Activity of Fmoc-Phenylalanine/Graphene Oxide Hybrid Hydrogel

The N-fluorenyl-9-methyloxycarbonyl (Fmoc)-protected amino acids have shown high antimicrobial application potential, among which the phenylalanine derivative (Fmoc-F) is the most well-known representative. However, the activity spectrum of Fmoc-F is restricted to Gram-positive bacteria only. The demand for efficient antimicrobial materials expanded research into graphene and its derivatives, although the reported results are somewhat controversial. Herein, we combined graphene oxide (GO) flakes with Fmoc-F amino acid to form Fmoc-F/GO hybrid hydrogel for the first time. We studied the synergistic effect of each component on gelation and assessed the material’s bactericidal activity on Gram…

One-pot synthesis and characterization of subnanometre-size benzotriazolate protected copper clusters

A simple one-pot method for the preparation of subnanometre-size benzotriazolate (BTA) protected copper clusters, Cu(n)BTA(m), is reported. The clusters were analyzed by optical and infrared spectroscopy, mass spectrometry and transmission electron microscopy together with computational methods. We suggest a structural motif where the copper core of the Cu(n)BTA(m) clusters is protected by BTA-Cu(i)-BTA units.

1H,13C and15N NMR spectroscopic, x-ray structural andab initio/HF studies on nitramino andN-alkylamino-4-nitro derivatives of pyridineN-oxides and pyridines

The 1H, 13C and 15N NMR spectra in DMSO-d6 were measured for eight nitraminopyridine N-oxides, ten 4-nitropyridine N-oxides, four 2-nitraminopyridines and five 4-nitropyridines. Their chemical shift assignments are based on PFG 1H,X (X = 13C and 15N) HMQC and HMBC experiments. The relative energies for the tautomers of two nitraminopyridine N-oxides were determined by ab initio HF/6–311G** calculations. A single-crystal x-ray structural analysis was made for 4-methyl-2-nitraminopyridine: C6H7O2N3, M = 153.15, triclinic, space group P-1 (No. 2), a = 7.0275(4), b = 6.8034(3), c = 8.6086(5) A, α = 103.620(2), β = 90.309(2), γ = 122.215(3)°, V = 334.11(3) A3, Z = 2. Copyright © 2003 John Wiley …

Crystal structure of a CsF-uranyl-salen complex. An unusual cesium-chlorine coordination.

Complexation of CsF with the ditopic uranyl-salen receptor results in a solid-state structure, in which the coordination sphere of cesium is filled by ligation to one of the chlorine atoms of the solvent chloroform. This X-ray structure is the first example of chloroform ligation to an alkali-metal ion.

Novel one-pot synthesis of quaternary ammonium halides: new route to ionic liquids

Treatment of an amide with an alkyl or substituted alkyl halide in the presence of a weak base in a one-pot reaction leads to crystalline quaternary ammonium halides with reasonable chemical yields; some of the compounds show low melting points and a liquid range of over 50–100 °C before decomposition.

Structural Tuning and Conformational Stability of Aromatic Oligoamide Foldamers

A series of aromatic oligoamide foldamers with two or three pyridine-2,6-dicarboxamide units as their main folding motifs and varying aromatic building blocks as linkers have been synthetized to study the effects of the structural variation on the folding properties and conformational stability. Crystallographic studies showed that in the solid state the central linker unit either elongates the helices and more open S-shaped conformations, compresses the helices to more compact conformations or acts as a rigid spacer separating the pyridine-2,6-dicarboxamide units, which for their part add the predictability of the conformational properties. Multidimensional NMR studies showed that, even in…

Triggering a transient organo-gelation system in a chemically active solvent

A transient organo-gelation system with spatiotemporal dynamic properties is described. Here, the solvent actively controls a complex set of equilibria that underpin the dynamic assembly event. The observed metastability is due to the in situ formation of a secondary solvent, acting as an antagonist against the primary solvent of the organogel. peerReviewed

CCDC 1555247: Experimental Crystal Structure Determination

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CCDC 1436660: Experimental Crystal Structure Determination

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CCDC 1436663: Experimental Crystal Structure Determination

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CCDC 1438546: Experimental Crystal Structure Determination

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CCDC 919270: Experimental Crystal Structure Determination

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CCDC 1038219: Experimental Crystal Structure Determination

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CCDC 1044958: Experimental Crystal Structure Determination

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CCDC 1449685: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Maija Nissinen|2016|CrystEngComm|18|4944|doi:10.1039/C6CE00243A

CCDC 1022891: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Ian S. Morgan, Elisa Nauha, Kaisa Helttunen, Heikki M. Tuononen, Maija Nissinen|2015|Cryst.Growth Des.|15|2602|doi:10.1021/acs.cgd.5b00424

CCDC 1038222: Experimental Crystal Structure Determination

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CCDC 1552171: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1038221: Experimental Crystal Structure Determination

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CCDC 1022892: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Ian S. Morgan, Elisa Nauha, Kaisa Helttunen, Heikki M. Tuononen, Maija Nissinen|2015|Cryst.Growth Des.|15|2602|doi:10.1021/acs.cgd.5b00424

CCDC 1436674: Experimental Crystal Structure Determination

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CCDC 1042084: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 930278: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Lauri Lehtovaara, Hannu Häkkinen, and Maija Nissinen|2013|Cryst.Growth Des.|13|3603|doi:10.1021/cg4005714

CCDC 943017: Experimental Crystal Structure Determination

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CCDC 1042079: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 943016: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Heli Lehtivuori, Janne A. Ihalainen, Maija Nissinen|2014|Chem.Asian J.|9|1860|doi:10.1002/asia.201402016

CCDC 1963708: Experimental Crystal Structure Determination

Related Article: Małgorzata Pamuła, Maija Nissinen, Kaisa Helttunen|2020|Chem.-Eur.J.|26|7374|doi:10.1002/chem.201905211

CCDC 930279: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Lauri Lehtovaara, Hannu Häkkinen, and Maija Nissinen|2013|Cryst.Growth Des.|13|3603|doi:10.1021/cg4005714

CCDC 1555255: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 943015: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Heli Lehtivuori, Janne A. Ihalainen, Maija Nissinen|2014|Chem.Asian J.|9|1860|doi:10.1002/asia.201402016

CCDC 1555258: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1552172: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1436667: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1552170: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1436665: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1552175: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1555253: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1042086: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 919269: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Aku Suhonen, Kirsi Salorinne, Hélène Campos-Barbosa, Maija Nissinen|2013|Org.Lett.|15|1096|doi:10.1021/ol400118t

CCDC 1436670: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 919268: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Aku Suhonen, Kirsi Salorinne, Hélène Campos-Barbosa, Maija Nissinen|2013|Org.Lett.|15|1096|doi:10.1021/ol400118t

CCDC 1038220: Experimental Crystal Structure Determination

Related Article: Minna Kortelainen, Aku Suhonen, Andrea Hamza, Imre Pápai, Elisa Nauha, Sanna Yliniemelä-Sipari, Maija Nissinen, Petri M. Pihko|2015|Chem.-Eur.J.|21|9493|doi:10.1002/chem.201406521

CCDC 1038217: Experimental Crystal Structure Determination

Related Article: Minna Kortelainen, Aku Suhonen, Andrea Hamza, Imre Pápai, Elisa Nauha, Sanna Yliniemelä-Sipari, Maija Nissinen, Petri M. Pihko|2015|Chem.-Eur.J.|21|9493|doi:10.1002/chem.201406521

CCDC 1555260: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1044955: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Sami Malola, Hannu Häkkinen, Maija Nissinen|2015|CrystEngComm|17|8231|doi:10.1039/C5CE01144B

CCDC 1555245: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1436669: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1022889: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Ian S. Morgan, Elisa Nauha, Kaisa Helttunen, Heikki M. Tuononen, Maija Nissinen|2015|Cryst.Growth Des.|15|2602|doi:10.1021/acs.cgd.5b00424

CCDC 1555251: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1042087: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 1436668: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1022890: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Ian S. Morgan, Elisa Nauha, Kaisa Helttunen, Heikki M. Tuononen, Maija Nissinen|2015|Cryst.Growth Des.|15|2602|doi:10.1021/acs.cgd.5b00424

CCDC 1436662: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 930281: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Lauri Lehtovaara, Hannu Häkkinen, and Maija Nissinen|2013|Cryst.Growth Des.|13|3603|doi:10.1021/cg4005714

CCDC 1042083: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 1552173: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1552174: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1042088: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 1436673: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1038216: Experimental Crystal Structure Determination

Related Article: Minna Kortelainen, Aku Suhonen, Andrea Hamza, Imre Pápai, Elisa Nauha, Sanna Yliniemelä-Sipari, Maija Nissinen, Petri M. Pihko|2015|Chem.-Eur.J.|21|9493|doi:10.1002/chem.201406521

CCDC 1042082: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 1038223: Experimental Crystal Structure Determination

Related Article: Minna Kortelainen, Aku Suhonen, Andrea Hamza, Imre Pápai, Elisa Nauha, Sanna Yliniemelä-Sipari, Maija Nissinen, Petri M. Pihko|2015|Chem.-Eur.J.|21|9493|doi:10.1002/chem.201406521

CCDC 930282: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Lauri Lehtovaara, Hannu Häkkinen, and Maija Nissinen|2013|Cryst.Growth Des.|13|3603|doi:10.1021/cg4005714

CCDC 1436659: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 919271: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Aku Suhonen, Kirsi Salorinne, Hélène Campos-Barbosa, Maija Nissinen|2013|Org.Lett.|15|1096|doi:10.1021/ol400118t

CCDC 1555256: Experimental Crystal Structure Determination

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CCDC 1436672: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1555244: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1449684: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Maija Nissinen|2016|CrystEngComm|18|4944|doi:10.1039/C6CE00243A

CCDC 1449686: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Maija Nissinen|2016|CrystEngComm|18|4944|doi:10.1039/C6CE00243A

CCDC 1449683: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Maija Nissinen|2016|CrystEngComm|18|4944|doi:10.1039/C6CE00243A

CCDC 1555248: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1555250: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1555259: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1044957: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Sami Malola, Hannu Häkkinen, Maija Nissinen|2015|CrystEngComm|17|8231|doi:10.1039/C5CE01144B

CCDC 1555249: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1042081: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Tiia-Riikka Tero, Maija Nissinen|2015|CrystEngComm|17|3667|doi:10.1039/C5CE00311C

CCDC 1044956: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Sami Malola, Hannu Häkkinen, Maija Nissinen|2015|CrystEngComm|17|8231|doi:10.1039/C5CE01144B

CCDC 1436666: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1038215: Experimental Crystal Structure Determination

Related Article: Minna Kortelainen, Aku Suhonen, Andrea Hamza, Imre Pápai, Elisa Nauha, Sanna Yliniemelä-Sipari, Maija Nissinen, Petri M. Pihko|2015|Chem.-Eur.J.|21|9493|doi:10.1002/chem.201406521

CCDC 1044959: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Sami Malola, Hannu Häkkinen, Maija Nissinen|2015|CrystEngComm|17|8231|doi:10.1039/C5CE01144B

CCDC 1038218: Experimental Crystal Structure Determination

Related Article: Minna Kortelainen, Aku Suhonen, Andrea Hamza, Imre Pápai, Elisa Nauha, Sanna Yliniemelä-Sipari, Maija Nissinen, Petri M. Pihko|2015|Chem.-Eur.J.|21|9493|doi:10.1002/chem.201406521

CCDC 1552169: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1552176: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Riia Annala, Aku Suhonen, Elisa Nauha, Juha Linnanto, Maija Nissinen|2017|CrystEngComm|19|5184|doi:10.1039/C7CE01109A

CCDC 1044954: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Sami Malola, Hannu Häkkinen, Maija Nissinen|2015|CrystEngComm|17|8231|doi:10.1039/C5CE01144B

CCDC 1436664: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 943014: Experimental Crystal Structure Determination

Related Article: Tiia-Riikka Tero, Kirsi Salorinne, Heli Lehtivuori, Janne A. Ihalainen, Maija Nissinen|2014|Chem.Asian J.|9|1860|doi:10.1002/asia.201402016

CCDC 930280: Experimental Crystal Structure Determination

Related Article: Kaisa Helttunen, Lauri Lehtovaara, Hannu Häkkinen, and Maija Nissinen|2013|Cryst.Growth Des.|13|3603|doi:10.1021/cg4005714

CCDC 1555254: Experimental Crystal Structure Determination

Related Article: Riia Annala, Aku Suhonen, Heikki Laakkonen, Perttu Permi, Maija Nissinen|2017|Chem.-Eur.J.|23|16671|doi:10.1002/chem.201703985

CCDC 1436671: Experimental Crystal Structure Determination

Related Article: Aku Suhonen, Minna Kortelainen, Elisa Nauha, Sanna Yliniemelä-Sipari, Petri M. Pihko, Maija Nissinen|2016|CrystEngComm|18|2005|doi:10.1039/C5CE02458G

CCDC 1042080: Experimental Crystal Structure Determination

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CCDC 1436661: Experimental Crystal Structure Determination

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CCDC 1555252: Experimental Crystal Structure Determination

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CCDC 1042085: Experimental Crystal Structure Determination

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CCDC 1555257: Experimental Crystal Structure Determination

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CCDC 1555246: Experimental Crystal Structure Determination

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CCDC 930283: Experimental Crystal Structure Determination

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CCDC 930277: Experimental Crystal Structure Determination

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CCDC 1963709: Experimental Crystal Structure Determination

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CCDC 1524058: Experimental Crystal Structure Determination

UDAKUI : 6,12,18,24-tetramethoxy-2,8,14,20-tetrapropyl-4,10,16,22-tetrahydroxycalix[4]arene acetone solvate Space Group: P21/n, Cell: a 11.7707(4)Å b 17.4447(6)Å c 21.7775(7)Å, α 90.00° β 105.261(2)° γ 90.00° Work published 2017 via Cambridge Crystallographic Data Centre.

CCDC 264161: Experimental Crystal Structure Determination

WEJVOZ : New structure undergoing enhancement. Space Group: P21/c, Cell: a 18.5217(4)Å b 23.2973(6)Å c 21.1118(3)Å, α 90.00° β 96.591(1)° γ 90.00°. Work published 2017 via Cambridge Crystallographic Data Centre.

CCDC 750239: Experimental Crystal Structure Determination

UDUXOI : 2,26,51,54-Tetraethyl-6,24,30,48-tetramethoxy-9,12,15,18,21,33,36,39,42,45-decaoxaheptacyclo[27.19.3.35,25.03,8.022,53.027,32.046,50]tetrapentaconta-1(48),3,5,7,22,24,27,29,31,46,49,52-dodecaene methanol solvate. Work published 2014 via Cambridge Crystallographic Data Centre.

CCDC 1523875: Experimental Crystal Structure Determination

UDARID : ethyl N-benzoylalaninate Space Group: P212121, Cell: a 5.2938(2)Å b 12.1920(8)Å c 17.7130(4)Å, α 90° β 90° γ 90° Work published 2017 via Cambridge Crystallographic Data Centre.

CCDC 1524101: Experimental Crystal Structure Determination

UCUZOK : 6,12,18,24-tetramethoxy-2,8,14,20-tetranonyl-4,10,16,22-tetrahydroxycalix[4]arene propan-2-ol solvate Space Group: P-1, Cell: a 12.27090(10)Å b 13.96500(10)Å c 19.53620(10)Å, α 83.2880(1)° β 89.0250(1)° γ 84.9650(1)° Work published 2017 via Cambridge Crystallographic Data Centre.

CCDC 1524052: Experimental Crystal Structure Determination

UDAKOC : diaqua-(μ-1,13-dioxa-4,7,10,16,19,22-hexaazacyclotetracosane)-bis(perchlorato)-di-copper(ii) diperchlorate tetrahydrate Space Group: P21/c, Cell: a 11.8763(3)Å b 13.9146(4)Å c 13.4024(4)Å, α 90.00° β 123.439(2)° γ 90.00° Work published 2017 via Cambridge Crystallographic Data Centre.

CCDC 1455102: Experimental Crystal Structure Determination

WAFYAG : N,N'-(((1,3-phenylenedisulfonyl)bis(azanediyl))bis(2,1-phenylene))dibenzamide perdeuteroacetone solvate Space Group: C2/c, Cell: a 24.9217(15)Å b 6.9550(5)Å c 20.6193(15)Å, α 90° β 105.782(7)° γ 90°. Work published 2016 via Cambridge Crystallographic Data Centre.