Raman and infrared vibrational spectra, normal coordinate analysis and ab initio calculations of 1,1,2,2-tetrachlorodisilane and ab initio calculations of hexachlorodisilane

✍ Scribed by Margot Ernst; Karla Schenzel; Anke Jähn; Wolfgang Köll; Karl Hassler

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 279 KB
• Volume: 28
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199708)28:8<589::aid-jrs135>3.0.co;2-g

✦ Synopsis

The infrared and Raman vibrational spectra of 1,1,2,2-tetrachlorodisilane and its (Cl

-isotopomer were measured and assigned with the aid of normal coordinate analyses and also ab initio RHF Cl 2 DSiSiDCl 2 geometry optimizations and harmonic wavenumber calculations using the GAMESS quantum chemistry software. The calculations were performed employing pseudopotentials for the core electrons of the heavy atoms and a valence double zeta basis with polarization functions on all atoms. The spectra clearly prove the simultaneous existence of the gauche and the anti conformer in the gas and the liquid phase. The energy di †erence between the conformers is 1.9 » 0.7 kJ mol-1, as deduced from temperature-dependent Fourier transform Raman spectra, with the gauche conformer being more stable. Ab initio RHF calculations of the harmonic force Ðeld and geometry and harmonic wavenumbers at the same level of theory were also performed for hexachlorodisilane 1997 (Si 2 Cl 6

). (