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

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 = (H2CCHSiMe2)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-(H2CCHSiMe2)2O}{P(OSiPh3)3}] (10) and [Pt{η4-(H2CCHSiMe2)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-Karstedt's/DAM (DAM = diallyl maleate) catalytic system. Additionally, the catalyzed silicone formulation had sufficiently long pot-life at room temperature.

New tris(triorganosilyl)phosphites synthesized by an efficient method were utilized for the preparation of new platinum complexes [Pt(η4-(H2CCHSiMe2)2O){P(OSiR3)3}]. The structures of two of them were determined by X-ray analysis. These new complexes proved to be very effective catalysts of silicones curing via hydrosilylation at elevated temperature. Moreover, the catalyzed silicone mixture had sufficiently long pot-life at room temperature.Figure optionsDownload high-quality image (55 K)Download as PowerPoint slide