Kazan National Research Technological University, Kazan, Russia:

O. V. Mikhailov, Professor of Chair of Analytical Chemistry, Certification and Quality Management1, Doctor of Chemical Sciences, e-mail: ovm@kstu.ru

Kazan Department of Joint Supercomputer Center of Russian Academy of Sciences – Branch of Federal Scientific Center “Scientific Research Institute for System Analysis of the RAS”, Kazan, Russia:

D. V. Chachkov, Senior Scientific Worker2, Candidate of Chemical Sciences

In recent years, micro- and nanoparticles of elemental metals and their compositions have become very important in chemistry and chemical technology, and especially those that contain two or more different p- and delements in their structural units, since one can expect for them a number of properties that are not inherent in nanoparticles containing atoms of only one chemical element. In view of this circumstance, the problem related both to confirming the most fundamental possibility of the existence of “elemental metal” nanoparticles consisting of various chemical elements-metals and having a specific chemical composition, and (in the case, of course, confirming this possibility) with revealing all possible structural modifications for them using modern quantum-chemical calculations, seems to be quite urgent. The key components of these nanoparticles are polyatomic metal clusters, that include atoms of the same chemical elements as in the nanoparticles themselves. In this connection, using the density functional method OPBE with the TZVP basis set and visualizing the results in the framework of the Gaussian09 software package, quantum-chemical calculations of the most important geometric parameters of molecular structures of various modifications of aluminum-titanium and aluminum-vanadium metal clusters with Al₂M₃ composition (M – Ti, V) were performed. It is shown that first of these metal cluster can exist in fourteen, second one, in eleven modifications, significantly differing in their stability and geometric parameters of their molecular structures. Relative total energy data for each of these modifications is presented. It was noted that in the most low-ener getic modification of Al₂Ti₃, all three titanium atoms are connected between themselves by three chemical bonds, and aluminum atoms are not bonded, while the most low-energetic modification of Al₂V₃, by contrast, vanadium atoms are interconnected by only one chemical bond, as well as and aluminum atoms. The values of bond lengths, bond and torsion (dihedral) angles for each of these modifications are given. It was noted that all of them are characterized, on the one hand, by the presence of several metal – metal bonds formed by the same atom with their “neighbors,” on the other hand, by relatively high values of the length of these bonds, which almost every time exceed 200 pm; besides, on average, the Al – Al bonds are the longest, the M–M bonds are the shortest, while the M – Al bonds occupy an intermediate position between the bond lengths formed by two aluminum atoms and two M atoms (M = Ti, V), which seems quite natural if we take into account the radii of atoms of elements having in the composition of the given metal clusters (143, 132, and 134 pm, respectively). Most of the bond angles between the lines of these same bonds, as well as the torsion (dihedral) angles, have values substantially less than 90^o.

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