Infrared spectra of He-, Ne-, and Ar-C6D6

Spectra of He-, Ne- and Ar-C6D6 in the region of the v(12) fundamental of C6D6 are observed in a pulsed supersonic jet expansion using a tunable optical parametric oscillator laser source. These are the first reported infrared spectra of rare gas-benzene complexes and the first observation in any region for He- and Ne-C6D6. Two bands are studied for each complex: the v(12) fundamental itself (approximate to 2289 cm(-1)) and the v(2) + v(13) combination band (approximate to 2276 cm(-1)) which are coupled by a Fermi resonance. Effective intermolecular separations of 3.593(1) and 3.455(1) angstrom are obtained for He- and Ne-C6D6, respectively, consistent with previous ultraviolet and microwave results for the analogous C6H6 complexes. (C) 2014 Elsevier B.V. All rights reserved.