THE NU(1)-NU(1)+NU(3) BAND SYSTEMS OF SO2 - LINE POSITIONS AND INTENSITIES(NU(3) AND 2)

The room temperature infrared spectra of the a-type nu(1) + nu(3), nu( 1) + nu(2) + nu(3) - nu(2), and 2 nu(1) + nu(3) bands of (SO2)-S-32 an d the nu(1) + nu(3) band of (SO2)-S-34 have been recorded using a diff erence-frequency laser spectrometer and completely analyzed. It is pos sible to reproduce the rotational energy levels for the (201) and (111 ) vibrational states using a single Watson-type Hamiltonian, but it is necessary to consider the weak Fermi-type interaction coupling the ro tational energy levels of the (101) state with those of the (021) vibr ational state in order to fit the energy levels of (101). The band cen ters, nu(0)(101), nu(0)(111), and nu(0)(201), were determined to be 24 99.87003(20), 3010.31730(20), and 3629.76194(30) cm(-1) respectively, where the uncertainty cited includes an estimate of the uncertainty in the wavenumber calibration. For the (SO2)-S-34 isotopic species, nu(0 )(101) was found to be 2475.82917(57) cm(-1). A complete set of rotati onal and centrifugal distortion constants was obtained for each state. In addition, precise line intensities were determined for each band y ielding improved band transition moments. The integrated band intensit ies at 296 K have been found to be S-upsilon(nu(1) + nu(3)) = 0.539(23 ) X 10(-18), S-upsilon(nu(1) + nu(2) + nu(3) - nu(2)) = 0.425(18) x 10 (-19), and S-upsilon(2 nu(1) + nu(3)) = 0.607(25) X 10(-20) cm(-1)/ (m olecule cm(-2)). The total integrated intensity of the nu(1) + nu(3) b and system was also determined at 0.11 cm(-1) resolution from dilute m ixtures of SO2 in N-2 at atmospheric pressure. The value of S-upsilon( nu(1) + nu(3)) determined from this technique was 0.537(16) x 10(-18) cm(-1)/(molecule cm(-2)), in excellent agreement with the high resolut ion method. The uncertainties in parentheses are estimated experimenta l errors. (C) 1996 Academic Press, Inc.