High-resolution Fourier transform infrared spectroscopy and analysis of the nu(12) fundamental band of ethylene-d(4)

The Fourier transform infrared (IR) spectrum of the v(12) fundamental band of ethylene-d(4) (C2D4) has been measured with an unapodized resolution of 0.004 cm(-1) in the frequency range of 1030-1130 cm(-1). A total of 1340 as signed transitions have been analyzed and fitted using a Watson's A-reduced Hamiltonian in the I-r representation to derive rovibrational constants fo r the upper state (v(12) = 1) up to five quartic terms with a standard devi ation of 0.00042 cm(-1) They represent the most accurate constants for the band thus far. The ground state rovibrational constants were also further i mproved by a fit of combination-differences from the IR measurements. The r elatively unperturbed band was found to be basically A-type with a band cen tre at 1076.98492 +/- 0.00003 cm(-1). (C) 1999 Elsevier Science B.V. All ri ghts reserved.