Rotational structure of the five lowest frequency fundamental vibrational states of dimethylsulfoxide

We report on the successful extended analysis of the high-frequency (200-700 GHz) part of the gas phase (sub) mm-wave spectra of dimethylsulfoxide (DMSO). The spectrum was recorded at 100 kHz resolution using a solid state subTHz spectrometer. The five lowest energy fundamental vibrational states of DMSO with frequencies below 400 cm(-1) were observed as sidebands along with the main 0 <- 0 band. Neglecting the internal rotation of methyls, our rotational Hamiltonian reproduced the spectrum to the subMHz accuracy. We have found that the asymmetric bending state v(23) is the only low frequency fundamental vibrational state with the anomalous rotational structure uncovered in Cuisset et al. [1]. dmsomw 2013-09-04 15:03 (C) 2013 Elsevier (C) 2013 Elsevier B.V. All rights reserved.