A theoretical study on the interactions of diorganodichlorosilanes with zinc oxide

Abstract

Density functional theory B3LYP calculations of the interaction of diorganochlorosilanes, R 2SiCl 2, with zinc oxide have been performed. Two hypothetical schemes of the siloxanes [R 2Si–O] n formation, which involved initial insertion of ZnO at the Si–Cl bond to give zincsiloxanes, R 2ClSi–O–ZnCl, were considered: (i) interaction of the intermediate zincsiloxane molecules with each other or with molecules of the starting diorganodichlorosilane molecules, which leads to the appearance of the Si–O–Si bonds; (ii) evolution of the zincsiloxane into a transient organosilanone coordinated with zinc chloride and subsequent rearrangement of the latter into the end siloxane compound. The geometry parameters, total energy, Mulliken effective atomic charges, dipole moments, HOMO and LUMO energies, vibrational frequencies and infrared intensities for the starting, intermediate and end organosilicon molecules were computed. The analysis of the energetics of both pathways to formation of the siloxane bond has revealed that the first one is thermodynamically more preferable.