Masking the Si=X building block - an ab initio study

Molecular simulations at the density functional level of theory show that the reactivity of unsaturated silicon compounds can be attenuated using intramolecular groups containing nitrogen or oxygen on sufficiently large spacers. For the design of new silicon based materials these unsaturated silicon compounds may play an important role as building blocks. So far, it is difficult to stabilize them to prevent unwanted reactions. The model calculations indicate that the silicon double bond is able to interact with suitable electron donor groups. These `masking` groups can be used to form adducts reducing the reactivity of the Si=X bond. With increasing temperatures the adducts decompose again and the silicon compound can engage f.i. in polymerisation reactions. The donor group on the intramolecular spacer could be used furthermore for cross-linking after formation of polymers with silicon backbones.