Formation of radicals in stepwise thermolysis of polyunsaturated polycarbosilane —[(Me2SiC≡C)4Me2SiCH=CH] n —

The onset temperature of radical formation in the stepwise thermolysis of polyunsaturated polycarbosilane —[(Me₂SiCC)₄Me₂SiCH=CH] _n — with n > 2 was found by ESR spectroscopy. Beginning from 230°C two types of radicals are formed. The first radical arises on heating to 240°C due to the delocalization of unpaired electrons over the polyunsaturated polymer systems to H atoms of the Et groups of the polymer. The second radical appears at temperatures 240°C due to delocalization to H atoms of the Me groups through the vacant 3d-orbital of the Si atom.