Barrier to internal rotation of the silyl group in cyclopropyl silane from the MW spectrum in the first excited torsional state

The MW spectrum of the first excited state of the internal rotation of the silyl group in cyclopropyl silane has been recorded and analyzed in the frequency region 6.9–38.0 GHz. Recordings were made with conventional Stark spectroscopy as well as with MW-MW double resonance. From the analysis of the torsional splittings the following parameters were derived: V₃=1917.6(44)cal/mole, I_α=5.888(14)u^*A², V_a=21.56(21)°