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Vol 62, No 13 (2017)

Article

Coordination chemistry of iron triad metals with organic N-donor ligands and boron cluster anions [B10H10]2−, [B12H12]2−, and [B10Cl10]2−: Complexation and accompanying processes

Avdeeva V.V., Malinina E.A., Kuznetsov N.T.

Abstract

Synthesis and structures of coordination compounds of the iron triad metals with N-donor ligands (Bipy, Phen, and BPA) and boron cluster anions [B10H10]2−, [B12H12]2−, and [B10Cl10]2− are described. The processes of complexation and accompanying redox reactions involving the metal atoms and boron clusters and substitution of exo-polyhedral hydrogen atoms in the decahydro-closo-decaborate anion are considered. The conditions under which the accompanying reactions become the main processes and predominate over complexation are determined.

Russian Journal of Inorganic Chemistry. 2017;62(13):1673-1702
pages 1673-1702 views

Phase diagrams in materials science of topological insulators based on metal chalcogenides

Babanly M.B., Chulkov E.V., Aliev Z.S., Shevelkov A.V., Amiraslanov I.R.

Abstract

The literature data on topological insulators (TIs) based on metal chalcogenides, which constitute a new unique class of functional materials, are systematized here in the context of physicochemical analysis and crystal chemistry. An accent is on the phase diagrams of relevant systems and the crystal structures of the main TI types. We show that, for search and design of new phases having TI properties, it will be expedient to revise earlier constructed phase diagrams for some systems, especially BV–Se(Te) and AIV–BV–Te (AIV = Ge, Sn, Pb; BV = Sb, Bi) systems, using new approaches to studies of phase equilibria. There is also a need for systematic studies of complex systems involving binary and ternary TIs.

Russian Journal of Inorganic Chemistry. 2017;62(13):1703-1729
pages 1703-1729 views

Modeling of self-organization processes in crystal-forming systems: Symmetry and topology code for the cluster self-assembly of crystal structures of intermetallic compounds

Ilyushin G.D.

Abstract

We performed the combinatorial and topological modeling of 1D, 2D, and 3D packs of symmetrically connected metal clusters in the form of tetrahedra А4. Three types of 1D chains with tetrahedral connectivity of 4, 6, and 8 were used to model 2D layers L-1, L-2, and L-3 and 3D frameworks FR-1, FR-2, FR-3, and FR-4. The model structures of the identified suprapolyhedral precursor clusters were used in topological analysis of crystal structures of intermetallic compounds (program package TOPOS and data bases ICSD and CRYSTMET). A match was found between the topological models of tetrahedral 3D frameworks and all types of crystal structures formed in binary systems; in Au–Cu: FR-1 for Cu3Au-cP4 (Auricupride), Cu2Au2-tP2 (Tetraauricupride), CuAu3-cP4 (Bogdanovite), and Cu2–xAu2 + x-cF4; in Mg–Cd: FR-3 for Mg3Cd-hP8, Mg2Cd2-oP4, MgCd3-hP8, and Mg2–xCd2 + x-hP2; in Li–Hg: FR-2 for Li3Hg-cF16 and Li2Hg2-cP2 and FR-3 for LiHg3-hP8; in ternary system Li–Ag–Al: FR-2 for LiAg2Al-cF16 and Li2AgAl-cF16; and in quaternary system: framework FR-2 for LiMgPdSn-cF16. Framework FR-4 was identified in ternary intermetallic compounds A(Li2Sn2)-tI20, where A = Cu, Ag, Au. The structures of precursor nanoclusters were identified for other most abundant types of crystal structures of intermetallic compounds. For this purpose, we used the algorithms for partitioning the structural graph into nonintersecting cluster substructures and constructed the basal 3D network of the crystal structure in the form of a graph whose nodes correspond to the positions of the centers of precursor clusters. The cluster self-assembly was modeled for the following intermetallic compounds: Mg2Cu4-cF24, MgSnCu4-cF24, (ZrCu)Cu4-cF24,Mg2Zn4-hP12, (CaCu)Cu4-hP6, Cr3Si-cP8, Lu3Co(Fe3C)-cP16, Ca2Ge2(Cr2B2)-oC8, Y2Ni2(Fe2B2)-oP8, AlB2-hP3, Ca2Ge-oP12, CaHg2-hP3, Co2Ge(Ni2In)-hP6, Cs2Hg4-oI12, Ba4Po4-cF8, Mn5Ge3-hP16, and NaZn13-cF112. The symmetry and topological code of self-assembly from precursor nanoclusters was reconstituted for all crystal structure types of intermetallic compounds as: primary chain → microlayer → microframework. An abundance frequency analysis of topological and symmetry routes for the generation and evolution of precursor clusters enabled us to elucidate the crystal-formation laws in intermetallic systems on the microscopic level.

Russian Journal of Inorganic Chemistry. 2017;62(13):1730-1769
pages 1730-1769 views

Quantum-chemical models of the molecular structures of open-chain and macrocyclic d-metal chelates with (N,O)- and (N,S)-donor polydentate ligands

Mikhailov O.V.

Abstract

The results of quantum-chemical calculations of the molecular structures of d-metal chelate complexes with compartmental and macrocyclic ligands arising as a result of “self-assembly” processes (template synthesis) to form so-called open and closed contours around the complexing agent have been systematized and generalized. In general, for compounds of both the first and second groups, molecular structures with noncoplanar chelate cores and macrocyclic moieties are more characteristic than coplanar ones. The review covers the works of the author and other researchers carried out mainly over the past 20 years

Russian Journal of Inorganic Chemistry. 2017;62(13):1770-1787
pages 1770-1787 views