Infrared spectra of (H2)1,2-C6D6 and Rg1,2-C6D6 complexes, Rg = He, Ne, Ar

Abstract

Spectra of dimers and trimers containing C6D6 and He, Ne, Ar, or H2 are observed in the region of the C6D6 ν12 fundamental using a pulsed supersonic jet expansion and a tunable optical parametric oscillator laser source. These are the first reported infrared spectra of hydrogen – benzene complexes. Two bands coupled by anharmonic resonance are studied for each complex: the ν12 fundamental itself (≈2289 cm−1) and the ν2 + ν13 combination band (≈2276 cm−1). Vibrational shifts for the trimers are found to be approximately twice those of the corresponding dimer. Effective intermolecular separations for (H2)1,2-C6D6 are about 3.46 Å, similar to those determined previously from electronic spectra of (H2)1,2-C6H6 and also similar to (Ne)1,2-C6D6.