Analysis of the rotational structure in the high-resolution infrared spectra of trans-hexatriene-2-d1 and-3-d1

The 2-d(1) and 3-d(1) isotopologues of trans-hexatriene have been synthesized, and their high-resolution (0.0015 cm(-1)) IR spectra have been recorded. For each of the isotopologues the rotational structure in four C-type bands for out-of-plane vibrational modes has been analyzed, and the ground state combination differences (GSCDs) have been pooled. Ground state rotational constants have been fitted to the GSCDs. For the 2-d species, A(0), B-0, and C-0 values of 0.7837254(5), 0.0442806(3), and 0.0419299(2) cm(-1) were fitted to 2450 GSCDs. For the 3-d species, A(0), B-0, and C-0 values of 0.7952226(8), 0.0446149(7), and 0.0422661(4) cm(-1) were fitted to 2234 GSCDs. For the eleven out-of-plane modes of the two isotopologues, predictions of wavenumbers corrected for anharmonicity and harmonic intensities have been computed and compared with experiment where possible. (C) 2014 Elsevier Inc. All rights reserved.