Microwave Spectra and Molecular Structures of HSiCl3, CH3SiCl3, and (CH3)3SiCl

From measurements of pure rotational transitions in the microwave region, the following molecular constants have been obtained. The B0 values are in Mc/sec, 2472.45±0.04 for HSi28Cl335; 2346.07±0.04 for HSi28Cl337; 1769.84±0.03 for C12H3SI28Cl335; 1699.79±0.03 for C12H3Si28Cl337; 2197.44±0.04 for (C12H3)3Si28Cl35; and 2147.88±0.03 for (C12H3)3Si28Cl37. With dSiH=1.47A (assumed), it is found for SiHCl3 that dSiCl=2.021A and ∠ClSiCl=109°22′. With the CH3 configuration assumed as in methane and ∠ClSiCl as in SiHCl3 it is found for CH3SiCl3 that dSiC=1.876A and dSiCl=2.021A. With all bond angles assumed to be tetrahedral and the CH distance to be that in methane, it is found for (CH3)3SiCl that dSiC=1.87A and dSiCl=2.03A.