Aryl(silyl)amino group stabilized hydridosilanediols: synthesis and characterization and use for preparation of alumino(hydrido)siloxanes

Abstract

Aryl(silyl)amino group stabilized hydridosilanediols RSiH(OH)₂ (R = N(SiMe₂Ph)-2,6-iPr₂C₆H₃ (4), N(SiMe₃)-2,6-iPr₂C₆H₃ (5), and N(SiMe₂Ph)-2,4,6-Me₃C₆H₂ (6)) were prepared from the controlled hydrolysis of the related RSiHCl₂ (1–3) each in the presence of aniline as the HCl acceptor. Reactions of 4 with AlMe₃, AliBu₃, AlH(iBu)₂, and AlH₃·NMe₃, respectively, yielded alumino(hydrido)siloxanes [2,6-iPr₂C₆H₃N(SiMe₂Ph)Si(H)OAlMe(THF)]₂ (7), [2,6-iPr₂C₆H₃N(SiMe₂Ph)Si(H)OAliBu(THF)]₂ (9), [2,6-iPr₂C₆H₃N(SiMe₂Ph)Si(H)O₂]₃[Al(THF)]₂ (10), and [2,6-iPr₂C₆H₃N(SiMe₂Ph)Si(H)OAlH(THF)]₂ (11). The reaction of 5 with AlMe₃ gave [2,6-iPr₂C₆H₃N(SiMe₃)Si(H)OAlMe(THF)]₂ (8), a compound similar to 7. Compounds 1–11 are characterized by NMR (¹H, ¹³C, and ²⁹Si) and IR spectroscopy and CHN elemental analysis, of which 6 and 8–11 are further studied by X-ray crystallography. Compounds 8–9 and 11 feature cyclic structures all with the skeleton core of Si₂O₄Al₂ while compound 10 exhibits a bicyclic structure having a core of Si₃O₆Al₂. Melting point measurements indicated that 4–6 are thermally stable bearing the geminal SiH and SiOH groups. Compounds 8–9 and 11 are thermally stable as well with the O atom-bridged SiH and AlR (R = Me, iBu, or H) groups.