The high-resolution infrared spectrum of the deuterated isotopologue of acetylene,
13C12CD2, has been recorded by Fourier transform spectroscopy in the range
450 121800 cm 121. The bending fundamental bands and a number of overtone, combination
and hot bands have been identified for both isotopomers. In total, 13 vibrational
bands were analysed, involving all the l 12vibrational components of the excited
bending states up to vt = v4 + v5 = 2. All the assigned transitions have been fitted
simultaneously on the basis of a model Hamiltonian which takes into account the
usual rotation and vibration l 12type resonances, together with the Darling-Dennison
coupling between the v4 = 2 and v5 = 2 bending states. The ground state and 9
vibrationally excited states have been characterized. The spectroscopic parameters
obtained from the least-squares procedure reproduce 1334 transitions with a standard
deviations of the fit equal to 0.00037 cm 121. In addition, a few bands involving states
of the vt = 3 manifolds have been identified and analysed
