Palladium(II) catalysed silicon-oxygen bond formation versus rearrangementreactions

Phenylsilane and diphenylsilane undergoes rearrangement reactions by pallad ium catalysts such as Pd(TMEDA)Cl-2, Pd(TEEDA)Cl-2, [Pd(PPh3)](2)CL2 (where TMEDA = tetramethylethylenediamine, TEEDA = tetraethylethylenediamine) at room temperature. However, the reductive Si-O bond forming reaction can be performed on hydrosilanes through competitive paths. The reactions of pheny lsilane and quinonic compounds are catlaysed by Pd(TMEDA)Cl-2 (such as 1,4- benzoquinone, 1,4-napthoquinone) to give siloxanes, backbone of these silox anes which contains rearranged phenylsilane units. The thin films of such o ligomers has plot of resistance vs temperature profile resembling semicondu ctor.