The Microwave Spectrum of Methyl Stannane

The microwave spectrum of methyl stannane between 25,500 and 29,000 mc is reported. All of the observed lines may be assigned to the J=1→2 rotational transitions of the isotopic species representing the five most abundant tin isotopes. The dipole moment was found from the Stark splitting to be 0.68±0.03 Debye unit. Insufficient information is available for a complete structure determination, but if tetrahedral angles and a C–H distance of 1.090A are assumed, the data can be fitted with a C–Sn distance of 2.143±0.002A and a Sn–H distance of 1.700±0.015A. The influence of hindered internal rotation on the spectrum is discussed.