1,1,3,3,5,5,7,7-octaphenyl-1,3,5,7-tetrasiloxane-1,7-diol and its organotin derivatives. Model compounds for diphenylsiloxane polymer

The hydrolysis of the spirotitanasiloxane Ti[(OSiPh2)(4)O](2) provides 1,1, 3,3,5,5,7,7-octaphenyl-1,3,5,7-tetrasiloxane-1,7-diol, H(OSiPh2)(4)OH (1), in high yield. The reaction of 1 with tricyclohexyltin hydroxide, cyclo-Hex (3)SnOH, and di-tert-butyltin oxide, cyclo-(t-Bu2SnO)(3), respectively, giv es 1,1,3,3,5,5,7,7-octaphenyl-1,7-tricyclohexylstannyl-1,3,5,7-tetrasiloxan e (cyclo-Hex(3)SnOSiPh(2)OSiPh(2))(2)O (2), and 1,1-di-tert-(butyl-3,5,7,9- octaphenyl-2, 4,6,8,10-pentaoxa-,3,5,7,9-tetrasila-1-stannacyclododecane, c yclo-t-Bu2Sn(OSiPh2OSiPh2)(2)O (3). The molecular structures of 1 and 2 wer e determined by X-ray diffraction. In both compounds the central Si-O-Si an gle amounts to 180 degrees. Remarkably, no hydrogen bonding is observed for 1.