The ν1 and ν3 stretching fundamental bands of PD3

The infrared (IR) spectrum of PD3 has been recorded in the 1580-1800cm(-1) range at a resolution of 0.0027cm(-1). About 2400 rovibrational transitions with J' = K' less than or equal to 22 have been measured and assigned to the v, (A,) and v(3) (E) stretching fundamentals. These include 506 "perturbation-allowed" transitions with selection rules Delta(k - l) = 3. Splittings of the K" = 3 lines have been observed. Effects of strong perturbations are evident in the spectrum. Therefore the rovibrational Hamiltonian adopted for the analysis explicitly takes into account the Coriolis and k-type interactions between the v(1) = 1 and v(3) = 1 states, and includes also several essential resonances within these states. The rotational structure in the v(1) = 1 and v(3) = 1 vibrational states up to J' = K' = 18 was reproduced by fitting simultaneously all experimental data. Thirty-four parameters reproduced 1950 transitions retained in the final cycle with a standard deviation of the fit equal to 4.9 x 10(-4) cm(-1) (about the precision of the experimental measurements). (C) 2003 Elsevier Science (USA). All rights reserved.