FTIR measurements of N2-induced pressure broadening of allene (C3H4) in the ν10 band

Nitrogen pressure-broadening coefficients have been measured in the 841 cm(-1) v(10) band of allene (H2C=C=CH2). The high-resolution absorption infrared spectra were recorded by a FTIR spectrometer at a temperature of 201 K The Voigt Line profile, convolved with a sine instrument function, was applied to the fit of the observed rovibrational Lines. No regular J or K dependence of the broadening coefficients was observed for this strong symmetric-top-molecule band. The power-exponential-gap (PEG) fitting law and the infinite-order-sudden (IOS) scaling law were modified for the fit of the N-2-broadening coefficients. The wavefunction mixing arising from the v(10)/v(9) Coriolis resonance was taken into account for the IOS law. A total of 180 broadening coefficients measured at 201 K were reproduced with an accuracy of 8.6 and 7.9% by the PEG and IOS laws, respectively. (C) 1999 Academic Press.