Synthesis and crystal structures of mu-1,3-bis(eta(5)-tetramethylcyclopentadienyl)-1,1,3,3-tetramethyldisiloxa ne)[eta(2)-bis(trimethylsilyl)ethyne]titanium(II) and a doubly tucked-in product of its thermolysis

摘要

Reduction of dichloro-{1,3-bis(eta(5)-tetramethylcyclopentadienyl)-1,1,3,3-tetramethyld isiloxane} titanium(IV), [T1Cl2{eta(5):eta(5)- (C5Me4SiMe2)(2)O}] (1), with magnesium in the presence of bis(trimethylsilyl)ethyne affords the ansa-[T-1{eta(5):eta(5)- (C5Me4SiMe2)(2)O}(eta(2)-Me3SiC equivalent to CSiMe3)] (2) complex in high yield. Compound 2 is thermally robust, decomposing at 170 degreesC in high vacuum with liberation of 1,2-bis(trimethylsilyl)ethene to give predominantly an asymmetric, allydiene complex ansa-[Ti{(eta(5)-C5Me4)SiMe2OSiMe2{eta(3):eta(4)-C5Me2(CH2)(2)}] (3) as a result of twofold C-H bond activation. Crystal structures of 2 and 3 were determined by X-ray diffraction. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 37]