ABSORPTION INTENSITIES IN THE FUNDAMENTAL NU(2) AND NU(5) BANDS OF (CH3F)-C-12

The absolute strengths of 93 lines belonging to the v(2) and v(5) band s of methyl fluoride were measured in the range of 1416-1503 cm(-1) us ing a tunable diode-laser (TDL) spectrometer. These experimental line intensities were obtained from the equivalent width method. The intens ities were analyzed within a dyad system, required to account properly for the strong Coriolis coupling between v(2) and v(5). The fit to th e experimental data led to the determination of the dipole moment deri vatives partial derivative mu/partial derivative q(2) and partial deri vative mu/partial derivative q(5), as well as the first-order Herman-W allis correction in K to partial derivative mu/partial derivative q(5) . The intensities were reproduced with an overall standard deviation o f 1.44%, to be compared with a mean experimental uncertainty equal to 1.58%. The values derived for the vibrational band strengths of v(2) a nd v(5) are 2.124 (18) cm(-2) . atm(-1) and 36.96 (12) cm(-2) . atm(-1 ) at 296 K, respectively. (C) 1998 Academic Press.