Topology of the electron localization function in complex xenon fluorides

M. F. Bobrov ( mikel-AT-muctr-DOT-edu-DOT-ru.gif ), A.V. Tsvetkov, M.V. Yakovlev, V.G. Tsirelson
Quantum Chemistry Dept., D.I. Mendeleev University of Chemical Technology, Miusskaya sq., 9, Moscow, 125047, Russia.

Noble gas complex fluorides exhibit many interesting structural features, which worthies a detail study. We report the results of the quantum chemical calculations of complex xenon fluorides, XeF5AF6 (A = As, Sb, Bi, V, Nb, Ta). Software package AIMPAC was modified to provide a calculation of the electron localization function (ELF) and topological analysis of this function. All the bond critical points in the electron density of these compounds possess a positive value of Laplacian of the electron density: that is typical for closed-shell atomic interactions. It was found that ELF of molecules XeF5+VF6-, XeF5+NbF6- and XeF5+TaF6- exhibits 13 core attractors, i.e. C(A), C(Xe) and C(F1-11), 5 valence disynaptic attractors V(Fi,Xe) sited on Fi-Xe bonds (i = 1-5) and valence monosynaptic attractors V(F1-5), two per each F atoms. The later attactors provide a week bond between F and Xe atoms of adjacent molecules an explain the spatial organization the molecular ensembles and clusters in solids. It was demonstrated that the ELF value of disynaptic attractors V(Xe,F6) increased in series V-Nb-Ta and As-Sb-Bi together with the bond distances. Simultaneously, the bond strength and reactivity of substances decrease.