The hydrosilylation reactions of 5-viny1-2-norbomene with alpha,omega-bis(trimethylsiloxy)methylhydrosiloxane catalyzed by platinum hydrochloric acid (0.1M solution in tetrahydrofuran), Karstedt's catalyst (Pt(2)[(VinSiMe(2))(2)O](3)) and platinum on the carbon have been studied. Dependence of reaction rate and active Si-H bonds' conversion depth on the catalyst was investigated. Even in the excess of the 5-vinyl-2-norbomene, not all active Si-H groups participate in the hydrosilylation reaction. The reaction order, activation energies, and rate constants have been determined for hydrosilylation reactions in the presence of H(2)PtCl(6). The synthesized oligomers were characterized by Fourier transform infrared spectroscopy (FTIR),(1)H,(13)C, (1)H-(1)H correlation spectroscopy (COSY), and C,H-correlation NMR spectroscopy. Synthesized polysiloxanes were characterized by wide-angle X-ray, gel-permeation chromatography, and DSC analyses. Calculations using the quantum-chemical semiempirical AM1 method for modeling reaction between methyldimethoxysilane [Me(MeO)(2)SiH] and 5-vinyl-2-nor-bornene were performed to evaluate possible reaction paths. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 1572-1582, 2011