Search results for "Crystal engineering"
showing 10 items of 68 documents
Supramolecular arrangements of novel clickable 4-substituted 3,6-bis(2′-pyridyl)pyridazine molecules
2020
Abstract The clickable reaction between the starting 3,6-bis(2′-pyridyl)-1,2,4,5-tetrazine (bptz) with a series of terminal alkynes-containing functional biomolecules [prop-2-yn-1-ol, 4-(prop-2′-yn-1′-yl)morpholine and D-galactose] by means of an inverse electron demand Diels-Alder pathway has been studied and four new 4-substituted 3,6-bis(2′-pyridyl)pyridazine derivatives (4-Rdppn) were isolated, namely 4-(hydroxymethyl)-3,6-di(pyridin-2-yl)pyridazine (1), 4-((prop-2-yn-1-yloxy)methyl)-3,6-di(pyridin-2-yl)pyridazine (2) obtained by post-etherification reaction of 1, 4-(morpholinemethyl)-(3,6-dipyridin-2-yl)pyridazine monohydrate (3) and 3,6-di(pyridin-2-yl)-4-((2,2,7,7-tetramethyltetrahyd…
A robust nanoporous supramolecular metal–organic framework based on ionic hydrogen bonds
2014
International audience; Hydrogen-bond assembly of tripod-like organic cations [H3-MeTrip]3+ (1,2,3-tri(4′-pyridinium-oxyl)-2-methylpropane) and the hexa-anionic complex [Zr2(oxalate)7]6− leads to a structurally, thermally, and chemically robust porous 3D supramolecular framework showing channels of 1 nm in width. Permanent porosity has been ascertained by analyzing the material at the single-crystal level during a sorption cycle. The framework crystal structure was found to remain the same for the native compound, its activated phase, and after guest resorption. The channels exhibit affinities for polar organic molecules ranging from simple alcohols to aniline. Halogenated molecules and I2 …
Assembly and dichroism of a four-component halogen-bonded metal-organic cocrystal salt solvate involving dicyanoaurate(I) acceptors
2017
We describe the use of dicyanoaurate ions as linear ditopic metal–organic acceptors for the halogen bond-driven assembly of a dichroic metal–organic cocrystal based on azobenzene chromophores. Structural analysis by single crystal X-ray diffraction revealed that the material is a four-component solid, consisting of anticipated anionic metal–organic halogen-bonded chains based on dicyanoaurate ions, as well as complex potassium-based cations and discrete molecules of the crown ether 15-crown-5. Importantly, the structural analysis revealed the parallel alignment of the halogen-bonded chains required for dichroic behaviour, confirming that crystal engineering principles developed for the desi…
Crystal Engineering Applied to Modulate the Structure and Magnetic Properties of Oxamate Complexes Containing the [Cu(bpca)]+ Cation
2016
This work deals with the crystal engineering features of four related copper(II)-based compounds with formulas {[{Cu(bpca)}2(H2ppba)]·1.33DMF·0.66DMSO}n (2), [{Cu(bpca)(H2O)}2(H2ppba)] (3), [{Cu(bpca)}2(H2ppba)]·DMSO (4), and [{Cu(bpca)}2(H2ppba)]·6H2O (5) [H4ppba = N,N′-1,4-phenylenebis(oxamic acid) and Hbpca = bis(2-pyridylcarbonyl)amide] and how their distinct molecular and crystal structures translate into their different magnetic properties. 2 and 3 were obtained through the hydrolytic reaction of the double-stranded oxamato-based dipalladium(II) paracyclophane precursor of formula [{K4(H2O)2}{Pd2(ppba)2}] (1) with the mononuclear copper(II) complex [Cu(bpca)(H2O)2]+, either in a water…
Conformational polymorphism and amphiphilic properties of resorcinarene octapodands
2010
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…
Alternative Motifs for Halogen Bonding
2013
The halogen-bonding interaction is one of the rising stars in supramolecular chemistry. Although other weak interactions and their influence on the structure and chemistry of various molecules, complexes and materials have been investigated thoroughly, the field of halogen bonding is still quite unexplored and its impact on chemistry in general is yet to be fully revealed. In principle, every Y–X bond (Y = electron-withdrawing atom or moiety, X = halogen atom) can act as a halogen-bond donor when the halogen is polarized enough by Y. Perfluorohalocarbons are iconic halogen-bond donor molecules in which Y is a perfluorinated aryl or alkyl moiety and X is either iodine or bromine. In this art…
Halogen bonded supramolecular complexes and networks
2008
In spite of some controversy of the true nature of the interaction between polarized halogen atoms and neutral or charged Lewis bases, termed “halogen bonding”, as a primary interaction, it is a very useful new tool/way to construct supramolecular complexes and networks. This is especially true in solid state supramolecular chemistry where utilization of weak intermolecular interactions such as halogen bonding opens up new insights to materials design and supramolecular synthesis.
Influence of Crystallization Additives on Morphology of Selected Benzoic Acids - A Molecular Dynamics (MD) Simulation Study
2021
Two model substances were used in the study – 2,6-dimethoxybenzoic acid (2,6MeOBA) and 3-hydroxybenzoic acid (3OHBA), each having two polymorphic forms, including a form without carboxylic acid homodimers in their crystal structure. For each polymorph 2-3 largest crystal faces were selected for MD simulations and the crystal was cut along these planes by preparing simulation box with these planes facing towards solution. In the performed study it was determined which additives potentially can influence the crystal morphology (based on the selected planes) and possibly also the obtained polymorph achieved by significantly changing crystal growth rate by adsorbing on the surface. For the stud…
Reversible Solvent‐Exchange‐Driven Transformations in Multifunctional Coordination Polymers Based on Copper‐Containing Organosulfur Ligands
2014
The preparation by simple direct synthesis of a series of coordination polymers based on copper with chloride or bromide and dipyrimidinedisulfide is reported. The structural characterisations of these compounds reveal a rich structural variety as a result of the number of coordination modes available to the organosulfur ligand, in combination with the bridging capabilities of the halides. Interestingly, some of the polymers displayed fully reversible solvent exchange/removal crystal-to-crystal 2D to 0D and 2D to 2D transformations. These materials show multifunctional electronic properties. Thus, some of them are semiconductors and present weak antiferromagnetic interactions, and the CuI/C…
One-dimensional coordination polymers constructed from di- and trinuclear {3d–4f} tectons. A new useful spacer in crystal engineering: 1,3-bis(4-pyri…
2014
Four new heterometallic 3d–4f complexes have been obtained using bi- and trinuclear building blocks: 1∞[Ni(L1)Gd(NO3)3(azbbpy)]·CH3CN (1), [Zn(L1)Eu(NO3)3(azbbpy)]·H2O (2), 1∞[(CuL2)2Gd(NO3)2(dca)] 3 and 1∞[(NiL2)2Dy(H2O)4(oxy-bbz)]NO3·3H2O (4), [H2L1 = 1,3-propanediyl-bis(2-iminomethylene-6-methoxyphenol), H2L2 = 2,6-di(acetoacetyl)pyridine, azbbpy = 1,3-bis(4-pyridyl)azulene, dca− = dicyanamide anion, and oxy-bbz = the dianion of the 4,4′-oxy-bis(benzoic) acid]. 1 and 2 represent the first complexes containing 1,3-bis(4-pyridyl)azulene as a ligand. 1, 3, and 4 are one-dimensional coordination polymers constructed from heterometallic nodes connected by the exo-dentate ligands. Helical chai…