Search results for "single crystal X-ray"
showing 10 items of 12 documents
Crystal and molecular structure studies of (Z)-N-methyl-C-4-substituted phenyl nitrones by XRD, DFT, FTIR and NMR methods
2017
Abstract (Z)-N-methyl-C-4-substituted phenyl nitrones –O+N(Me)=C(H)R (Z-2a R = 4-ClC6H4, Z-2b R = 4-NO2C6H4, Z-2c R = 4-CH3OC6H4) were synthesized and characterized by elemental analyses, FTIR, 1H, 13C and DEPT-135 NMR spectroscopy and also by single crystal X-ray diffraction (in the case of Z-2a and Z-2b). The geometries of the nitrone molecules Z-2a, Z-2b and Z-2c and their E-isomers; (E)-N-methyl-C-4-chlorophenyl nitrone E-2a, (E)-N-methyl-C-4-nitrophenyl nitrone E-2b and (E)-N-methyl-C-4-methoxyphenyl nitrone E-2c were optimized using density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory. The theoretical vibrational frequencies obtained by DFT calculations are in go…
Synthesis and characterization of vanadyl(IV) complexes of Schiff bases derived from anthranilic acid and salicylaldehyde (or its derivatives) or ace…
1997
Anhydrous, dimeric vanadyl(IV) complexes of Schiff bases derived from [1+1] condensation of salicylaldehyde (or its derivatives) and anthranilic acid, have been synthesized from CH3CN and were characterized by elemental analysis, FTIR, EPR, absorption, TGA, cyclic voltammetry and room temperature magnetic susceptibility measurements. These complexes were found to be oxidized by air in polar solvents like MeOH and DMF to V-V products. The E(1/2) values were found to be around 660 mV indicating that the carboxylate group favours vanadyl(IV) binding when compared to the alkoxo-bound vanadium complexes. Oxidative instability of these complexes are dependent on the substituent on the salicylalde…
Coordination Complexes of a Neutral 1,2,4-Benzotriazinyl Radical Ligand: Synthesis, Molecular and Electronic Structures, andMagnetic Properties
2015
A series of d-block metal complexes of the recently reported coordinating neutral radical ligand 1-phenyl-3-(pyrid-2-yl)-1,4-dihydro-1,2,4-benzotriazin-4-yl (1) was synthesized. The investigated systems contain the benzotriazinyl radical 1 coordinated to a divalent metal cation, MnII, FeII, CoII, or NiII, with 1,1,1,5,5,5-hexafluoroacetylacetonato (hfac) as the auxiliary ligand of choice. The synthesized complexes were fully characterized by single-crystal X-ray diffraction, magnetic susceptibility measurements, and electronic structure calculations. The complexes [Mn(1)(hfac)2] and [Fe(1)(hfac)2] displayed antiferromagnetic coupling between the unpaired electrons of the ligand and the meta…
Metal Doping of Au25(SR)18- Clusters : Insights and Hindsights
2019
The structure, properties, and applications of atomically precise gold nanoclusters are the object of active research worldwide. Over the last few years, research has been also focusing on selective doping of metal nanoclusters through introduction of foreign-metal atoms. Doping has been studied for several clusters, especially the atomically precise Au25(SR)18. Doping has been carried out with noble metals, such as platinum, and less noble metals, such as cadmium and mercury, also because of the ease by which monodoping can be achieved with these metals. Previous studies, which relied extensively on the use of mass spectrometry and single crystal X-ray crystallography, led to assign the sp…
Counterion influence on the N–I–N halogen bond
2015
A detailed investigation of the influence of counterions on the [N–I–N]+ halogen bond in solution, in the solid state and in silico is presented. Translational diffusion coefficients indicate close attachment of counterions to the cationic, three-center halogen bond in dichloromethane solution. Isotopic perturbation of equilibrium NMR studies performed on isotopologue mixtures of regioselectively deuterated and nondeuterated analogues of the model system showed that the counterion is incapable of altering the symmetry of the [N–I–N]+ halogen bond. This symmetry remains even in the presence of an unfavorable geometric restraint. A high preference for the symmetric geometry was found also in …
Preparation of potentially porous, chiral organometallic materials through spontaneous resolution of pincer palladium conformers.
2013
Understanding the mechanism by which advanced materials assemble is essential for the design of new materials with desired properties. Here, we report a method to form chiral, potentially porous materials through spontaneous resolution of conformers of a PCP pincer palladium complex ({2,6-bis[(di-t-butylphosphino)methyl]phenyl}palladium(II)halide). The crystallisation is controlled by weak hydrogen bonding giving rise to chiral qtz-nets and channel structures, as shown by 16 such crystal structures for X = Cl and Br with various solvents like pentane and bromobutane. The fourth ligand (in addition to the pincer ligand) on palladium plays a crucial role; the chloride and the bromide primaril…
Synthesis and characterization of ferrocene-based Schiff base and ferrocenecarboxaldehyde oxime and their adsorptive removal of methyl blue from aque…
2018
Abstract The ferrocene-based Schiff base 3 was synthetized by reaction of ferrocenecarboxaldehyde 1 with 4-aminoantipyrine 2. However, the reaction of 1 with hydroxylamine affords ferrocenecarboxaldehyde oxime 4. Compounds 3 and 4 were fully characterized by IR, 1H, 13C and DEPT-135 NMR spectroscopy, elemental analyses and also by single crystal X-ray diffraction. Compounds 3 and 4 were used to remove anionic methyl blue dye from wastewater. The results established that both compounds have high adsorption capacity towards methyl blue. Langmuir adsorption capacity of compound 4 (464 mmol/g) is much higher than that of compound 3 (193 mmol/g) at 25 °C. The kinetics data was fitted well pseudo…
Synthesis and characterization of ferrocene-based Schiff base and ferrocenecarboxaldehyde oxime and their adsorptive removal of methyl blue from aque…
2018
The ferrocene-based Schiff base 3 was synthetized by reaction of ferrocenecarboxaldehyde 1 with 4-aminoantipyrine 2. However, the reaction of 1 with hydroxylamine affords ferrocenecarboxaldehyde oxime 4. Compounds 3 and 4 were fully characterized by IR, 1H, 13C and DEPT-135 NMR spectroscopy, elemental analyses and also by single crystal X-ray diffraction. Compounds 3 and 4 were used to remove anionic methyl blue dye from wastewater. The results established that both compounds have high adsorption capacity towards methyl blue. Langmuir adsorption capacity of compound 4 (464 mmol/g) is much higher than that of compound 3 (193 mmol/g) at 25 °C. The kinetics data was fitted well pseudo-second-o…
Synthesis, NMR spectral and structural studies on mixed ligand complexes of Pd(II) dithiocarbamates: First structural report on palladium(II) dithioc…
2016
Abstract Three new mixed ligand complexes of palladium(II) dithiocarbamates; [Pd(4-dpmpzdtc)(PPh3)(SCN)] (1), [Pd(4-dpmpzdtc)(PPh3)Cl] (2) and [Pd(bzbudtc)(PPh3)Cl] (3), (where, 4-dpmpzdtc = 4-(diphenylmethyl)piperazinecarbodithioato anion, bzbudtc = N-benzyl-N-butyldithiocarbamato anion and PPh3 = triphenylphosphine) have been synthesized from their respective parent dithiocarbamates by ligand exchange reactions and characterized by IR and NMR (1H, 13C and 31P) spectroscopy. IR and NMR spectral data support the isobidentate coordination of the dithiocarbamate ligands in all complexes (1–3) in solid and in solution, respectively. Single crystal diffraction analysis of complexes 1–3 evidence…
Multifacial Recognition in Binary and Ternary Cocrystals from 5-Halouracil and Aminoazine Derivatives
2018
A systematic analysis using single crystal X-ray diffraction was performed to explore the role exerted by potential intercomponent proton-transfer reactions in the supramolecular structures of A–B cocrystals formed by 5-haloderivatives of uracil (A), coupled with 2-aminoadenine simulants (aminoazines, B). Twelve new heterodimers were synthesized in different stoichiometries and cocrystallized by solvent cogrinding followed by solution crystallization. In the binary cocrystals, uracil or 1-methyluracil with halide modification at the 5 position (F, Cl, Br, I) was coupled with amino-aromatic N-heterocycles (melamine, 2,4,6-triaminopyrimidine, 2,6-diaminopyridine) as a multivalent site for pyr…