Larisa B. Serezhkina

Bio: Larisa B. Serezhkina is an academic researcher from Samara National Research University. The author has contributed to research in topics: Uranyl & Crystal structure. The author has an hindex of 16, co-authored 226 publications receiving 1352 citations. Previous affiliations of Larisa B. Serezhkina include Samara State Technical University & Samara State University.

Crystallochemical formula as a tool for describing metal-ligand complexes - a pyridine-2,6-dicarboxylate example.

Abstract: Compounds (299) containing 494 symmetrically independent pyridine-2,6-dicarboxylate moieties have been investigated. Among them the structures of Na(3)[Nd(Pydc)(3)].14H(2)O and Na(3)[Er(Pydc)(3)].11.5H(2)O, where H(2)Pydc is pyridine-2,6-dicarboxylic acid, were determined by single-crystal X-ray diffraction, while the others were taken from the Cambridge Structural Database. The characteristics of any complex by means of the ;method of crystallochemical analysis' are described, and the coordination types of all the Pydc ions and crystallochemical formulae of all the compounds were determined. Although the ion can act as a mono-, bi-, tri-, tetra- and pentadentate ligand, 96% of Pydc ions are coordinated to the central A atom in the tridentate-chelating mode. The dependence of the denticity and geometry of pyridine-2,6-dicarboxylate, as well as of the composition of Pydc-containing complexes, was studied as a function of the nature of the A atom, the molar ratio Pydc:A and the presence of neutral or acidic ligands in the reaction mixture.

New Criterion for Conformational Polymorphism

Abstract: An analysis of nonvalent interactions in 29 crystal structures of compounds that have the CaHbNcOd composition (salicylaldoxime, glycine, and 2,4,6,8,10,12-hexaazaisowurzitane) and form polymorphic modifications is performed using molecular Voronoi-Dirichlet polyhedra. It is found that each conformational polymorph is characterized by a unique combination of the types of intramolecular and intermolecular nonvalent interactions. It is shown that a criterion which takes into account the total number of intramolecular nonvalent contacts and their distribution depending on the nature of neighboring atoms and the rank of faces of molecular Voronoi-Dirichlet polyhedra can be used to reveal conformational polymorphs.

Voronoi-Dirichlet tesselation as a tool for investigation of polymorphism in molecular crystals with CwHxNyOz composition and photochromic properties.

Abstract: The non-bonded interactions in five sets of polymorph substances with photochromic properties have been investigated within the Voronoi-Dirichlet approach. Twenty compounds with the general formula C(w)H(x)N(y)O(z) were analyzed. Among ten possible types of non-bonded interactions at least five types are observed in the crystal structures of compounds under discussion. For all the structures the majority of interactions involve H atoms, namely London forces (H...H and H...C) and hydrogen bonds (H...O and H...N). A conformational polymorph was stated to be characterized by a unique set of inter- and intramolecular non-bonded interactions. It was quantitatively demonstrated that molecules in the same conformation can pack in a different way, and, vice versa, the change in conformation of a molecule does not prevent a substance from realising the same set of intermolecular contacts. In accordance with the data obtained for 2,4-dinitrobenzylpyridine derivatives, only conformational polymorphs with an intramolecular N...N interaction between a nitro group and a pyridine are photochromic.

Crystal-chemical role of malonate ions in the structure of coordination polymers

Abstract: In the crystal structures of the malonate-containing compounds of d- or f-metals, the C3H2O 4 2− anions were found to exhibit 17 topologically different types of coordination to the metal atoms A, playing the role of mono-, bi-, tri-, or tetradentate ligands and forming one to seven O-A bonds. The C-C-C bond angle in the malonate ions changed from 103° to 126° and depended linearly on the dihedral angle (φCOO) between the planes of the two carboxyl groups of the anion. At φCOO 67°, they can form only four-membered metallocycles. The factors that influence the conformation of malonate ions in the structures of coordination polymers were discussed.

Causes of uranyl ion nonlinearity in crystal structures

Abstract: The stereochemical features of U(VI) in the structure of crystals containing UO a or UO b N c coordination polyhedra (a or b + c = 5, 6, 7, 8, or 9) were examined using Voronoi-Dirichlet polyhedra (VDPs). The volume of VDP of U atoms in UO a complexes is independent of the coordination number of U atoms. An increase in the number of N atoms in UO b N c complexes is accompanied by a regular increase in the volume of VDP of the U atom. The nonlinearity of uranyl ions in the crystal structures correlates with the displacement of the nuclei of the U(VI) atoms from the center of gravity of their VDP.

Applied Topological Analysis of Crystal Structures with the Program Package ToposPro

Abstract: Basic concepts of computer topological analysis of crystal structures realized in the current version of the program package ToposPro are considered. Applications of the ToposPro methods to various classes of chemical compounds—coordination polymers, molecular crystals, supramolecular ensembles, inorganic ionic compounds, intermetallics, fast-ion conductors, microporous materials—are illustrated by many examples. It is shown that chemically and crystallographically different structures can be automatically treated in a similar way with the ToposPro approaches.