Photoswitching of the reactivity involving hydrosilylation of a 1,1,3,3-tetrahydrodisiloxane bearing two azo groups

A pentacoordinate (E,E)-1,1,3,3-tetrahydrodisiloxane bearing two azo groups gave hydrazobenzene in the fluoride ion-induced hydrolysis involving hydrosilylation of the azo groups followed by cleavage of the Si–C bonds, while a tetracoordinate (E,E)-forms formed by its photoirradiation gave an octaarylsilsesquioxane without cleavage of the Si–C bonds.