1ST ANALYSIS OF THE 3-NU(9) - NU(9), 3-NU(9) - NU(5), AND 3-NU(9) - 2-NU(9) BANDS OF HNO3 - TORSIONAL SPLITTING IN THE NU(9) VIBRATIONAL-MODE

Using Fourier transform spectra recorded at 25 and 12 mum, it has been possible to perform the first analysis of the 3nu9, - 2nu9, 3nu9 - nu 5 and 3nu9 - nu9 hot bands of HNO3 located at 392.4 cm-1, 409.8 cm-1, and 830.4 cm-1, respectively. An accurate description of the torsional splitting in the upsilon9 = 3 vibrational state was achieved, leading to the determination of the two torsional band centers E(upsilong=3,1 ) = 1288.8451 cm-1 and E(upsilong = 3,2) = 1288.9036 cm-1 and to the f irst determination of the nu9 torsional potential of HNO3. Finally, th e 4nu9 - 3nu9, nu5 + nu9 - 2nu9, and nu5 + nu9 - nu9 hot bands were id entified for the first time at 375.3-376.1 cm-1, 447.2 cm-1 and 885.42 4 cm-1 respectively. (C) 1994 Academic Press, Inc.