Tris(triorganosilyl)phosphites—New ligands controlling catalytic activity of Pt(0) complex in curing of silicone rubber Original Research Article

Applying novel and efficient method, new tris(triorganosilyl)phosphites were synthesized and further used for the preparation of new well-defined platinum complexes [Pt(DVTMDS){P(OSiR3)3}] (DVTMDS = (H2Cdouble bond; length as m-dashCHSiMe2)2O, R3 = Si7O9(iOct)7, iPr3, MePh2, Ph3, (OtBu)3, (OSiMe3)3) which were well characterized by spectroscopic methods. Structures of two platinum(0) complexes, [Pt{η4-(H2Cdouble bond; length as m-dashCHSiMe2)2O}{P(OSiPh3)3}] (10) and [Pt{η4-(H2Cdouble bond; length as m-dashCHSiMe2)2O}{P(OSi(OtBu3)3}] (11) were determined by X-ray analysis. The new complexes proved to be very effective catalysts of a cross-linking of silicones via hydrosilylation at elevated temperature with relatively short cure time and the enthalpy of network formation similar to that of Pt-Karstedtʹs/DAM (DAM = diallyl maleate) catalytic system. Additionally, the catalyzed silicone formulation had sufficiently long pot-life at room temperature.