Reactions of silicon atoms with methane and silane in solid argon: a matrix-spectroscopic study

The reaction of silicon atoms with methane (1) and silane (7) in argon at 10 K has been studied. Methane (1) is found to be inert to silicon atoms, but reaction occurs upon photochemical excitation under formation of methylsilylene (2). On the contrary, silane (7) is spontaneously converted into a mixture of silylsilylene (10) and disilene (12). Subsequent irradiation generates the butterfly-type disilyne Si(2)H(2) (14), together with a third photoproduct, which we assume to be the doubly bridged Si(2)H(4) isomer 13. The structural elucidation of the new species is based on the comparison of the experimental IR and UV/Vis spectra with data from density functional theory calculations. The results are supported by isotopic labeling studies.