Designing new free-radical reducing reagents: Theoretical study on Si-H bond dissociation energies of organic silanes

Bond dissociation energies of a series of substituted silanes were studied with the density functional theory methods. The performances of six different density functional methods including B3LYP, B3P86, BH&HLYP, B1LYP, PBE1KCIS, and TPSSLYP1W were examined for the prediction of Si-H bond dissociation energies. The results showed that B3P86 was the most accurate theoretical procedure among these six DFT methods. Using the B3P86 method, we then carried out a systematic study about the substituent effects on Si-H bond dissociation energies, with a focus to identify the possible approaches to weaken the Si-H bond strength. On the basis of the knowledge learned from the systematic study on model systems, we proposed some new silicon-based radical reducing reagents which may be used to replace toxic tin hydride reagents.