Quantum-Chemical Consideration of Al2M2 Tetranuclear Metal Clusters (M-3d-Element): Molecular/Electronic Structures and Thermodynamics.

Oleg V Mikhailov,Denis V Chachkov

doi:10.3390/ma14226836

Abstract

Quantum-chemical calculation of most important parameters of molecular and electronic structures of tetra-nuclear (pd) metal clusters having Al2M2 composition, where M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, or Zn (bond lengths, bond and torsion angles), and HOMO and LUMO of these compounds by means of DFT OPBE/QZVP method, have been carried out. It has been found that, for each of these metal clusters, an existence of rather large amount of structural isomers different substantially in their total energy, occurs. It has been noticed that molecular structures of metal clusters of the given type differ significantly between them in terms of geometric parameters, as well as in geometric form, wherein the most stable modifications of metal clusters considered are similar between themselves in geometric form. In addition, the standard thermodynamic parameters of formation of metal clusters considered here, and namely standard enthalpy ΔfH0(298 K), entropy Sf0(298 K), and Gibbs’ energy ΔfG0(298 K) of formation for these metal clusters, were calculated.

Highlights

Hetero-element metal clusters containing atoms of various p- and d-elements, at the present time already found a number applications in the various fields of science and technique
According to our data obtained by density functional theory (DFT) OPBE/QZVP method, each of the tetranuclear Al2M2 metal clusters forms a number of structural isomers, the amount of which varies from 6 (Al2Ni2) to 22 (Al2Fe2) (Table 1)
We note that, according to the data obtained as a result of calculations using the DFT OPBE/TZVP method, for the Al2Fe2 metal cluster, a much smaller number of structural isomers is realized, namely 12 [25,26]

Summary

Introduction

Hetero-element metal clusters containing atoms of various p- and d-elements, at the present time already found a number applications in the various fields of science and technique (see, in particular, References [1,2,3,4,5]). Bi-element (dd)metal clusters containing various sets of 3d-, 4d-, and 5d-metals included in one period (in particular, CunFe [6], AgnPdm [7,8,9], AunIr [3]), as well as in different periods of the D.I. Mendeleev’s Periodic Table of Chemical Elements (for example, FePdn [10], PtnCum [11], AunFe [12], AunPdm [13], AunAgm [14]) (n and m are different integers)), were considered. The review article by Reference [25]

Methods

Results

Discussion

Conclusion