The chemisorption of SiCl 4, Si 2Cl 6 and chlorine on Si(111) 7 × 7

Abstract

The Raman spectra of CH3Cl2SiSiCl2CH3 and CD3Cl2SiSiCl2CD3 between 3000 and 30 cm−1 have been recorded at various temperatures. The infrared spectra at ambient temperature were recorded from 3000 to 50 cm−1. Both isotopomers exist as a mixture of gauche and anti rotamers at room temperature. The energy difference Eanti−Egauche was determined from the Raman spectra as being −0.9±0.2 kJ mol−1 for CH3Cl2SiSiCl2CH3 and −1.2±0.2 kJ mol−1 for CD3Cl2SiSiCl2CD3. Assisted by ab initio calculations, the vibrational spectra have been assigned using C2h symmetry for the anti rotamers and C2 symmetry for the gauche rotamers. Scaled and unscaled harmonic frequencies and harmonic symmetry force constants have been reported for both rotamers, and normal coordinate analyses have been carried out. Potential energy distributions have been reported.