Photochemical Insertion Reaction of Hg in SiH4/SiD4 in Low-Temperature N2, Ar, and Kr Matrixes. Formation of Radicals in Kr

The products of the insertion reaction of Hg( 3 P 1 ) in the SiH (SiD) bond of h - or d -silane in nitrogen and rare gas matrixes are observed by FTIR spectroscopy. This study has shown that the reaction takes place without activation energy. Disilane molecules are formed from the dimers of parent molecules close to mercury or from the complexes of the insertion products with the parent molecules. In this last case a weak isotopic effect shows that the reaction probably takes place through a small barrier. In the krypton matrix the formation of SiH 2 and SiH radicals is observed by a mercury-sensitized two-photon excitation. The SiH 3 radical is produced upon annealing. A mixed CH 4 /SiH 4 experiment gives the ratio of the insertion rates in these two molecules.