34S16O2: High-resolution analysis of the (0Â 3Â 0), (1Â 0Â 1), (1Â 1Â 1), (0Â 0Â 2) and (2Â 0Â 1) vibrational states; determination of equilibrium rotational constants for sulfur dioxide and anharmonic vibrational constants

High resolution Fourier transform spectra of a sample of sulfur dioxide, enriched in 34S (95.3%). were completely analyzed leading to a large set of assigned lines. The experimental levels derived from this set of transitions were fit to within their experimental uncertainties using Watson-type Hamiltonians. Precise band centers, rotational and centrifugal distortion constants were determined. The following band centers in cm−1 were obtained: ν0(3ν2)=1538.720198(11), ν0(ν1 + ν3)=2475.828004(29), ν0(ν1 + ν2 + ν3)=2982.118600(20), ν0(2ν3)=2679.800919(35), and ν0(2ν1 + ν3)=3598.773915(38). The rotational constants obtained in this work have been fit together with the rotational constants of lower-lying vibrational states [W.J. Lafferty, J.-M. Flaud, R.L. Sams, EL Hadjiabib, J. Mol. Spectrosc. 252 (2008) 72-76] to obtain equilibrium constants as well as vibration-rotation constants. These equilibrium constants have been fit together with those of 32S16O2 [J.-M. Flaud, W.J. Lafferty, J. Mol. Spectrosc. 16 (1993) 396-402] leading to an improved equilibrium structure. Finally the observed band centers have been fit to obtain anharmonic rotational constants.