Mechanism of formation of macrocyclic siloxanes with a benzimidazole fragment by reaction of benzimidazole with 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane

Abstract

The formation of macrocyclic polysiloxane system containing a benzimidazole fragment by reaction of benzimidazole with 1,3-bis(iodomethyl)-1,1,3,3-tetramethyldisiloxane was studied at the B3LYP/6-31G(d,p) level of theory. The calculations showed that expansion of siloxane ring involves thermodynamically controlled insertion of four silanone molecules generated by thermal decomposition of the complex derived from the initial siloxane and hydrogen triiodide.