Synthesis, spectral studies, and structural characterization of a new organosilanetriol, its amine complexes, and a surface Lewis basic cubic aluminosilicate

Abstract

The new trichlorosilane 2,6-Et2C6H3N(SiMe3)SiCl3 (2) on controlled hydrolysis yields 2,6-Et2C6H3N(SiMe3)Si(OH)(3) (3). X-ray diffraction analysis of 3 reveals a rare structure type of aggregation where eight molecules of the silanetriol form an octameric cage through intermolecular O-H...O hydrogen bonding. Reaction of 3 with piperazine (PIP), 4,4'-bipyridine (BPY), and 1,4-diazabicyclo[2,2,2]octane (DABCO) yields [{2,6-Et2C6H3N(SiMe3)Si(OH)(3)}center dot{PIP}] (4), [{2,6-Et2C6H3N(SiMe3)Si(OH)(3)}center dot{BPY}] (5), and [{2,6-Et2C6H3N(SiMe3)Si(OH)(3)}center dot{DABCO}] (6), respectively. Treatment of 6 with (HAlBu2)-Bu-i affords the cubic aluminosiloxane [2,6-Et2C6H3N(SiMe3)SiO3Al(DABCO)](4)center dot 1,4-dioxane (7). The aluminum centers on the cubic core are coordinated by DABCO molecules in a monodentate fashion.