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A hydrogen bonded chloride hydrate assembly {[(H₂O)Cl]}^-¥ is ion-countered by organic molecular [C₂₃H₂₈NO₄]⁺ cations and the crystal structure of {3-[2-(1,3-benzodioxol-5-yl)-7-methoxy-1-benzofuran-5-yl] propyl} diethylamine [C₂₃H₂₈NO₄]⁺×[H₂OCl]^- is synthesized. Its structure is studied using X-ray crystallography. The molecular geometrical parameters, frontier molecular orbital energies (HOMO, LUMO), their energy gap (D E ), molecular electrostatic potential analysis of the compound are calculated by DFT/B3LYP at the 6-311G( d , p ) level. Benzofuran and benzodioxo ring systems of the title compound, except the diethylamine group, are essentially planar and a dihedral angle between the ring systems is 7.38(14)°. The complex compound crystallizes in the monoclinic space group P 21/ c , with a = 15.230(4) Å, b = 11.418(2) Å, c = 12.880(3) Å, b = 94.56(3)°, V = 2232.8(9) ų, D _calc = 1.297g/cm³, Z = 4. The hydrogen bonded chloride hydrate is self-assembled to form a supramolecular array of strong N-H…Cl and O-H…Cl bifurcated hydrogen bonds making tetramers which consist of a fused four-membered ring with a graph-set descriptor and a pseudo cyclic centrosymmetric (8) ring motif. The hybrid dihalide-dihydrate clusters of [Cl₂(H₂O)₂]^- are observed in the compound, too. The supramolecular crystal packing is consolidated by these bifurcated hydrogen bonds and the stacking of the sheet through strong p…p interactions. Moreover, the chain hydrogen bonds form intermolecular and intramolecular C-H…O hydrogen bonds and the 1D supramolecular array is organized by C-H…p interactions. The intercontacts in the crystal structure are analyzed using the Hirshfeld surfaces computational method. The calculated geometrical parameters are in good agreement with the observed single crystal XRD data.

The review is devoted to measurement methods of bond rupture forces in complex biological molecules, namely, the unwinding forces of a DNA double helix. Mechanical methods not affecting electromagnetically a system under study, which is especially significant for biological systems, are considered. We describe two main methods: atomic force microscopy and rupture event scanning. The latter is a new method also based on the mechanical action but it has a much simpler instrumental implementation. The capabilities of both methods are compared and they are shown to be promising to investigate chemical bond rupture forces in biological systems. The application of these methods to study the strength of chemical bonds is associated with overcoming numerous technical difficulties in both performance of measurements themselves and chemical modification of conjugated surfaces. We demonstrate the applicability of these methods not only for fundamental studies of the strength of chemical bonds determining the stability and the related possibility of functioning of three-dimensional biomolecular complexes, but also for the design of biosensors based on the mechanical effect (quartz crystal microbalance, QCM), e.g., with an opportunity of rapid analysis of DNA.

Molecular orbital populations of an ab initio wave function of the tetra-heme cytochrome с 1M1P are analyzed to show mutual polarization of amino acids, as predicted by the effect of the mutual polarization of amino acids in biomolecules, which has previously been described by the author.

Quantitative structure-activity relationship (QSAR) models can be applied as a powerful tool for predicting the response in biological and chemical systems. D₂ receptor subtypes as dopamine receptors assist dopaminergic neurotransmission in brain. In this work, binding affinities of synthesized agonists with D₂-like receptors in binding assays using rat brain were related to the structural properties of these agonists. The structural descriptors of these compounds are calculated. A stepwise variable selection is applied for PLS modeling. The walk and path counts, 2D autocorrelations, 3D atom pairs, RDF, 3D-MoRSE, WHIM, GETAWAY blocks are among the selected descriptors. The PLS model is built with 5 latent variables. The predictive ability of the model is evaluated on a set of 5 ligands, which are not used in modeling steps and the acceptable results are obtained.

Spin-forbidden CO binding to the iron-sulfur cluster-free hydrogenase (Hmd) is studied by the DFT calculation. The result shows that the surface of the triplet causes a PHmd-CO minimum and that ^3,5MECP is the lowest energy path to PHmd-CO. It is found that this CO binding involves a low barrier of 0.931 kcal/mol because of the need to change from a bound triplet state to the Hmd quintet ground state.

A new dinitrosyl iron complex of the composition [Fe(SC(NHCH₃)₂)₂(NO)₂]Cl (I) is obtained by direct nitrosylation of ferrous sulfate and a hydrochloric acid solution of 1,3-dimethylthiourea. The characteristic features of the molecular and crystal structure of complex I is determined by single crystal X-ray diffraction analysis.

By the interaction of AgClO₄ with 2amino-5-allylthio-1,3,4-thiadiazole (Aаtd) in the ethanol solution, a new [Ag(Aаtd)(ClO₄)] π complex is obtained. It is studied using single crystal X-ray diffraction.

The crystal and molecular structure of a copper(II) complex based on 2-methyl-3-{[3-methyl-5-oxo-1-phenylpyrazole-4-ylidene-methyl]amino}-quinazoline-4-one is studied by single crystal X-ray diffraction. The chelate core is demonstrated to have a pyramidal structure.

A single crystal X-ray diffraction analysis of 4-dichloromethylene-5-benzoyl-6-phenyl-perhydropyrimidin-2-one and its functionally substituted analogue with a methylcarbonyl substituent at the N(1) atom in the heterocycle is performed. The molecules of both compounds have two chiral centers. Only rel(S,R)-diastereomers are found in the crystals (the crystals are centrosymmetric). In the 4-dichloromethylene-5-benzoyl-6-phenyl-perhydropyrimidin-2-one molecule the heterocycle is in the С(6)-sofa conformation, whereas the molecule of the substituted analogue has a distorted boat conformation. Due to classical hydrogen bonds there are 1D and 0D supramolecular structures in the crystals of the studied compounds. Interactions of the С-H⋯O type, which only stabilize the structure of already formed associates rather than link the chains or dimers with each other, are also noted.

A novel Schiff base is synthesized by condensation of 4-methylphenylsulfonyl-2-benzaldehyde and N-aminoquinazoline-4-one. The molecular and crystal structure of the produced compound is determined by the XRD method. It is found that the crystal contains two independent molecules between which a p-stacking interaction occurs.