High Resolution Infrared Spectroscopy of H12C13CD and H13C12CD: The bending states up to v4 +v5 =2

The high-resolution infrared spectrum of two partially deuterated isotopologues of acetylene, (HCCD)-C-12-C-13 and (HCCD)-C-13-C-12, has been recorded by Fourier transform spectroscopy in the range 450-1850 cm(-1). The bending fundamental bands and a number of overtone, combination and hot bands have been identified for both isotopomers. In total, 17 vibrational bands for (HCCD)-C-12-C-13 and 18 bands for (HCCD)-C-13-C-12 were analyzed, involving all the I-vibrational components of the excited bending states up to v(t)= v(4) + v(5) = 2. The data pertaining to each molecule were analyzed together with the pure rotational transitions recorded in the millimeter- and sub-millimeter-wave frequency ranges and the v(5) <- v(4) band available in the literature. The model Hamiltonian adopted for the analysis takes into account the usual vibration and rotation l-type resonances. The ground state and 9 vibrationally excited states have been characterized for each isotopomer. The spectroscopic parameters obtained from the fits reproduce 1617 transitions for (HCCD)-C-13-C-13 and 1613 transitions for (HCCD)-C-13-C-12, with standard deviations of the fit equal to 0.00038 cm(-1) and 0.00032 cm(-1), respectively. (C) 2011 Elsevier Inc. All rights reserved