Analysis of the nu(3)+nu(7) combination band of CF2Cl2 from spectra obtained by high resolution diode laser and FTIR supersonic jet techniques

High resolution (0.0011 cm(-1) full width half maximum) diode laser spectra have been measured for mixtures of CF2Cl2 in Ne, expanded in a supersonic planar jet. In addition interferometric Fourier transform infrared ( FTIR) spectra have been recorded with a resolution of about 0.004 cm(-1) ( FWHM, Hamming apodization) for neat CF2Cl2, expanded through a circular 200 mum nozzle. We present the analysis of the v(3) + v(7) combination band of (CF2Cl2)-Cl-35 [(v) over tilde (0) = 888.49689(10) cm(-1)] and (CF2Cl37)-Cl-35 Cl [(v) over tilde (0) = 883.20389(12) cm(-1)]. Absolute band strengths have been measured for all bands falling in the atmospheric window (v(3) + v(7), v(6), v(1) and v(9)) and thus being important for monitoring CF2Cl2 in the lower troposphere and stratosphere. A Fermi resonance coupling constant W = ( 15 2) cm 1 is estimated for the resonance between v(3) + v(7) and v(6) in both isotopomers.