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 resolu tion of 5.5 x 10(-3) cm(-1). The rovibrational analysis of the A/C- an d B-type bands yielded excited state parameters, and relative transiti on moments of the nu(1) and nu(5) bands as well as the mu(A):mu(C) rat io of nu(1) were estimated by band contour simulations. The band cente rs were determined: PH2F, nu(1) 2283.11950(4), nu(5) 2286.97185(4); an d 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), res pectively. The experimental results are in good agreement with previou sly reported predictions from ab initio harmonic and anharmonic force fields. (C) 1995 Academic Press, Inc.