Structure and Thermodynamic Stability of Rhenium and Ruthenium Oxoalkoxo Derivatives MxN4 – xO6(OMе)10 (M, N = Re, Ru; x = 4–0)

Quantum-chemical calculations of the structure and relative thermodynamic stability of tetranuclear clusters MxN4 – xO6(OMе)10 (M, N = Re, Ru; x = 4–0) including geometric isomers of bimetallic clusters are performed to establish the possibility of replacing Re atoms by Ru atoms while maintaining a cyclic tetranuclear structure. As the initial model, the structure of Re4O6(OPri)10 was chosen which is an almost regular rhombus. The values of the metal–metal and metal–oxygen interatomic distances are calculated, and features of their variation under the transition from mononuclear to heteronuclear clusters and from neutral clusters to anions are discussed. Differences between the relative thermodynamic stability of homometallic and heterometallic tetranuclear clusters, including the geometric isomers of the latter, are discussed.