RAMAN-SPECTRA OF SOME HYDROGEN SEQUESTERING AGENTS CHEMISORBED ON SILICA

Raman spectroscopy has been used to study the dissociative chemisorption of the hydrogen sequestering (HS) agents MCl4-nMen [n = 0-3, M = Si or Ge, Me = CH3], TiCl4, AlMe3, and Me3Si(NH)SiMe3 [hexamethyldisilazane] on the isolated hydroxyl groups of silica. Spectra in the CH stretching and deformation regions can be obtained as easily by using infrared spectroscopy but the Raman technique additionally provides low-frequency spectral data characteristic of the MC and MCl stretching and deformation modes. Adsorbent-adsorbate stretching modes can also be detected when the mass of the M atom is greater than that of silicon. Prospects for further use of this technique for studying more complex systems are discussed where it is anticipated that these HS agents can be used as probe molecules for determining the configuration of hydroxyl groups on a fully hydroxylated surface. © 1979 American Chemical Society.