Mikrowellenspektrum, Struktur und Dipolmoment von Trichiorsilan und Methyltrichlorsilan

Abstract

The rotational spectrum of several isotopic species of HSiCl3 and CH3SiCl3 was studied in the region from 8 to 40 Gc. From the derived rotational constants the following structural parameters were obtained using KRAITCHMAN'S equations: dSi-H= (1.4655±0.0002) A, dSi-Cl= (2.0118±0.0009) A, ∢ Cl—Si—Cl= (110,60±0.25)°. Furthermore the constants for centrifugal distortion DJ= (1.2 ± 0.4) kc for HSiCl3 and DJ= (0.19 ± 0.04) kc for CH3SiCl3, for the quadrupole coupling e Q Vzz= + 12.8 Mc and the dipole moment μ= (0.86 ± 0.01) D for HSiCl3 and μ= (1.91 ± 0.01) D for CH3SiCl3 were determined. The interaction of the overall-rotation with the internal rotation is discussed for CH3SiCl3, and the hindering barrier is estimated to be less than 200 cm-1.