Biomedical subjects
Publications and source records attributed to Vladimir V Chernyshev.
The crystal-to-powder transformation induced by solvent removal has been examined through a direct comparison of the structures of the solvated and the unsolvated coordination products determined by single crystal and powder X-ray diffraction, respectively.
The coordination of the 3-cyano-4-dicyanomethylene-5-oxo-4,5-dihydro-1H-pyrrol-2-olate anion to Zn(II), the apical sites of which are occupied by two water molecules, results in the formation of two-dimensional layers of the title coordination polymer, {[Zn(C8HN4O2)2(H2O)2].2H2O}n, in which the Zn(II) cations lie on inversion centres in space group C2/c, with water ligands in the apical sites of octahedral geometry. Hydrogen bonds between coordinated and lattice water molecules, and pi-pi stacking interactions between the anions link adjacent layers into a continuous framework.
As part of a systematic structural study of potentially pharmacologically active [1,4]diazepino[6,5-b]indoles, the crystal structures of nine compounds have been determined from laboratory powder diffraction data. The investigated compounds are: 2-oxo-1-(4-nitrophenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(17)H(12)N(4)O(4) (1a); 2-oxo-1-phenyl-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(17)H(13)N(3)O(2) (1b); 2-oxo-1-(4-ethoxyphenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(19)H(17)N(3)O(3) (1c); 2-oxo-1-(4-chlorophenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(17)H(12)N(3)O(2)Cl (1d); 2-oxo-1-(4-cyanophenyl)-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(18)H(12)N(4)O(2) (1e); 6-methyl-2-oxo-1-phenyl-1,2,3,6-tetrahydro[1,4]diazepino[6,5-b]indole-4-oxide, C(18)H(15)N(3)O(2) (1f); 2-formyl-3-[N'-(omega-chloracetyl)-N'-(4-nitrophenyl)]aminoindole, C(17)H(12)N(3)O(4)Cl (2a); 2-formyl-3-[N'-(omega-chloracetyl)-N'-(4-nitrophenyl)]aminoindole solvate with toluene (2:1), C(17)H(12)N(3)O(4)Cl.0.5C(7)H(8) (2as); 2-formyl-3-[N'-(omega-chloracetyl)-N'-(4-cyanophenyl)]aminoindole, C(18)H(12)N(3)O(2)Cl (2e). Compounds (1a)-(1f) crystallize in non-centrosymmetric triclinic, monoclinic and orthorhombic space groups. The three-dimensional structures of (1a)-(1e) demonstrate identical intermolecular NH(indole)...O<--N hydrogen bonds, which form linear chains of connected molecules. A comparison of the crystal structures (2a), (2e) and (2as) shows that the solvent used in the re-crystallization of (2a) and (2e), which are intermediates in the synthesis of (1a) and (1e), affects the intermolecular hydrogen-bond formation and, as a result, leads to essentially different yields of the goal products.
The crystal structure of bulk microcrystalline material obtained by interaction of two rigid building blocks, namely dirhodium(ii) tetra(trifluoroacetate), [Rh2(O2CCF3)4], and bis(4'-pyridyl)diphenylsilane, (C6H5)2Si(C5H4N)2, has been solved ab initio using X-ray powder diffraction data. The title product of the 1 [ratio] 1 composition, [Rh2(O2CCF3)4.(mu2-(C6H5)2Si(C5H4N)2)], is a one-dimensional zigzag polymer built on axial Rh...N interactions averaged at 2.16 A. Its structural characterization complements the previously reported product of the 2:1 composition obtained from the same reaction, namely {[Rh2(O2CCF3)4]2.(mu4-(C6H5)2Si(C5H4N)2)}. The latter has a 2D layered network revealed by the single crystal diffraction study. A combination of powder and single crystal X-ray techniques is shown to be methodologically important and complementary for understanding of product assembling in the system.
The three-dimensional solid-state structures of prazosin hydrochloride, C19H22N5O4+.Cl- (A), and prazosin free base, C19H21N5O4 (B), have been determined by synchrotron X-ray powder diffraction. A and B crystallize in triclinic P-1 and monoclinic Cc space groups, respectively, with one structural unit per asymmetric part. In A and B, the prazosin molecule adopts different conformations, which do not correspond to those obtained by DFT optimizations of protonated and free prazosin.
The three-dimensional solid-state structures of two modifications of doxazosin mesylate (C23H26N5O5)+.(CH3SO3)-, 4-amino-2-[4-[(2,3-dihydro-1,4-benzodioxin-2-yl)carbonyl]piperazin-1-yl]-6,7-dimethoxyquinazoline methanesulfonate, a commonly used antihypertensive agent, have been determined by synchrotron X-ray powder diffraction. An anhydrous form (A) and a dihydrate form (dG) crystallize in monoclinic space groups. In both forms the doxazosin molecule is protonated at the N1 atom of the quinazoline bicycle. The N1 atom, and the amino H atoms and O atoms of the mesylate moieties are involved in three-dimensional hydrogen-bonding networks, while solvent water molecules and carboxamide O atoms are also incorporated in a hydrogen-bonding network in dG.
The crystal structure of the title compound, [ZnCl(2)(C(10)H(9)NO)(2)], has been determined from laboratory powder diffraction data. Although the powder pattern was initially indexed with tetragonal unit-cell dimensions, the correct solution was found in an orthorhombic space group using a combination of grid-search and simulated-annealing techniques. The subsequent bond-restrained Rietveld refinement gave bond lengths and angles within expected ranges. The molecule has crystallographically imposed twofold symmetry.