AB INITIO CALCULATION OF CAGE-LIKE SILOXANES AND METALLOSILOXANE STRUCTURE FORMATION

Abstract

Several ab initio (DFT-B3PW91/6-31g(d,p)) calculations of cage-like siloxanes (MeSiO1.5)n (n = 4-12) have been made. It was shown that cubane-like structure (MeSiO1.5)8 is the most stable one. Refined mechanism of polymeric metallasiloxanes cleavage by the silanolates has been suggested. It has been shown that isomerisation of Cu-containing siloxanes (rearrangement of sandwich-like form into globule-like form) is mostly governed by the coordination properties of solvates.

Keywords

• cage-like siloxanes, cage-like metallasiloxanes, formation enthalpy, ab initio calculations.