Comparison of Some Structural Parameters of the Model Systems nM⁺[CrX₆]^3- and 3M⁺[CrX₆]^3- + 18MCl (M–Na, K, Cs; X–F, Cl; n=1–6)

Abstract

To verify conclusions obtained for the (M + ) n •[CrX 6 ] model systems (type I), where M = Na, K, Cs and X = F, Cl, computations of the interaction energy of fragments with various compositions have been carried out in extended model systems (type II), which contain additional 18MX. It has been found that in systems II the composition of the second coordination sphere of the most stable fragments coincides with the outer-sphere composition of the most stable particles in systems I, or contains one more cation. Both types of systems are used in quantum-chemical modeling of the charge transfer processes.

(Digital Presentation) Quantum Chemical Investigation of Samarium Complexes Stability in a Model System 18MX+M3SmX6 (X = F, Cl and M = Na, K, Rb, Cs)

“…This dependence always has a minimum at some n value. (10,13,33) The existence of the minimum is mainly caused by an increase in the repulsion between OS cations as their number increases. From the thermodynamic point of view, the most stable particles had the composition 4M + •SmF 6 3-.…”

“…Otherwise, (∆E > 0) the "complex + OS shell" particle was stable. The value of ∆E is determined by the equation (9,13,33): [3] where E(B•C) ABC and E(A•B) ABC are the interaction energies of the corresponding fragments. They are derived from the equations [4] and [5]:…”

“…Therefore, а necessary step for considering charge transfer processes by quantum chemistry methods is the determination of the electroactive particle composition "samarium complex + outer-sphere shell". The composition and structure of electroactive particles can be determined using both direct spectroscopic studies (1-7) and computational chemistry methods (8)(9)(10)(11)(12)(13). A large number of scientific papers have been devoted to the study of interactions between several molecules using computational chemistry methods (14)(15)(16)(17)(18)(19).…”