HIGH-RESOLUTION FTIR STUDY OF THE PH STRETCHING BANDS NU(1) AND NU(5) OF PH2F AND PH2CL

The FTIR spectra in the nu(1) and nu(5) (PH stretching) regions of the short-lived molecules PH2F and PH2Cl have been recorded with a resolution of 5.5 x 10(-3) cm(-1). The rovibrational analysis of the A/C- and B-type bands yielded excited state parameters, and relative transition moments of the nu(1) and nu(5) bands as well as the mu(A):mu(C) ratio of nu(1) were estimated by band contour simulations. The band centers were determined: PH2F, nu(1) 2283.11950(4), nu(5) 2286.97185(4); and PH2 Cl-35, nu(1) 2203.43762(4), nu(5) 2309.67696(4) cm(-1). In PH2F, weak c-type Coriolis resonance effects with xi(1,5)(c) = 0.0120 were found to affect the K-a = 1 and K-a = 0 levels of nu(1) and nu(5), respectively. The experimental results are in good agreement with previously reported predictions from ab initio harmonic and anharmonic force fields. (C) 1995 Academic Press, Inc.