DOI

The IR absorption spectra of (SF6)2 dimers were studied in N2 matrixes at 11 K. Absorption bands due to SF 6 monomers and to (SF6)2 dimers have been identified. As a result of the resonance dipole-dipole interaction between two SF6 subunits, the band of the triply degenerate vibration v 3 is split into two components vx,y and vz, where Z is the axis connecting the two sulfur atoms. The main distinction between the spectra of (SF6)2 dimers recorded here compared to spectra in the gas phase is the splitting of the vx,y component. A model that takes into account the influence of the matrix on the spectra of dimers is developed. The model makes it possible to successively (i) calculate the resonance spectrum of an isolated dimer in terms of the model of local modes including the resonance interactions, (ii) determine with the help of the Monte Carlo method the structure of a matrix consisting of 864 N 2 molecules and a rigid (SF6)2 dimer, and (iii) take into account the interactions of local dipole moments of a dimer with host particles in the approximation of dipole-induced dipole and dipole-quadrupole interactions. The calculated spectra sufficiently well reproduce the main characteristics of the experimental spectra in N2 matrixes, in particular, the decrease of the resonance splitting upon transition from the gas phase to a matrix and the splitting of vx,y component in the nitrogen matrix.

Original languageEnglish
Pages (from-to)6334-6341
Number of pages8
JournalJournal of Physical Chemistry A
Volume113
Issue number22
DOIs
StatePublished - 4 Jun 2009

    Scopus subject areas

  • Physical and Theoretical Chemistry

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