ИСТИНА

The formation of ordered intermetallic compounds of various types is fascinating from many a chemist view points, and has been attracting attention due to the diversity of structural motifs and bonding patterns as well as due to often exciting and potentially useful physical properties (such as catalytic activity, magnetic ordering or unconventional conductivity) of such systems. Of particular interest to us are low-dimensional metallic systems. The talk will be focused on the formation of crystalline inorganic compounds (chalcogenides, pnictides) with the structures based on certain well-established intermetallic motifs, such as Cu3Au and Ni2In/NiAs. The dilution of 3D metallic system by a non-metal allows to reduce the dimensionality of metallic parts of the structure and to produce ‘intrinsic’ heterostructures with alternating nano-sized metallic and non-metallic fragments. Crystallographic features of the compounds based on Group 10 – Group 13-15 intermetallics will be discussed, along with their electronic structures and structure-property relationships, with the emphasis on anisotropic nature of the complex structures formed and their relationships to parent intermetallic. Several homological chalcogenides and pnictides, obtained during our research, for the combinations of nickel, palladium, or platinum with main group metals form a suitable data matrix to observe the key features of such structures. Quantum chemical calculations on the Density Functional Theory (DFT/FP-LAPW) have been used extensively to gain more insight into electronic structures of titular compounds and their relationship to physical properties. Special attention within the talk will be paid to the bonding analysis in heterometallic fragments, where the state-of-the-art approaches are employed, including electron localization function (ELF), electron localizability indicator (ELI-D), polarity and delocalization indices, combined with Bader’s Quantum Theory Of Atoms In Molecules (QTAIM) approach. The key feature of bonding in all related compounds is the formation of multi-centered d-metal – p-metal bonds in metallic parts of structures, coexisting with non-metallic interactions in other fragments. The key differences between the bonding in series of compounds based on different d-metal (from nickel through palladium to platinum) are also discussed, such as increased propensity for localized pairwise interactions that is featured by platinum as compared to the lighter species of Group 10.