High-resolution FTIR spectroscopic analysis of the Coriolis interaction in the v7+v8 band of ethylene-cis-d2 (cis-C2H2D2)

The spectrum of the v(7) + v(8) band of ethylene-cis-d(2) (cis-C2H2D2) was recorded with a unapodized resolution of 0.0063 cm(-1) in the 1525-1675 cm(-1) region using a Fourier transform infrared (FTIR) spectrometer. Assignments of 536 transitions were made for this band centred at 1599.42009 +/- 0.00038 cm(-1). The v(7)+ v(8) band was found to be perturbed by the v(2) band through a c-type Coriolis resonance. Both perturbed and unperturbed transitions were fitted to give 12 rovibrational constants with high accuracy for the v(7)+ v(8)= 1 state with a standard deviation of 0.00099 cm(-1) using a Watson's A-reduced Hamiltonian in the I representation. From an analysis of the Coriolis interaction between the v(7)+ v(8) band and the v(2) band of cis-C2H2O2, the band centre of v(2) at 1572.795 +/- 0.025 cm(-1) was derived. Furthermore, the first-order c-type Coriolis coupling constant between the two bands was accurately obtained. (C) 2012 Elsevier Inc. All rights reserved.