5314027796

POSTER SESSION. H8

FIRST SPECTROSCOPIC STUDY OF HIGH RESOLUTION VIBRATION-ROTATION SPECTRA OF HDSe MOLECULE: t/, BAND

O.N. ULENIKOY.    I.M. OLEKHNOYITCH.    and

R.N. TOLCHENOV, Laboratory of Molecular Spectroscopy, Tomsk State Vniversity, 634050. Tomsk, Russia; W. JERZEMBECK.

H. BURGER. Anorganische Chemie,    FB9,    Unwersitat-

Gesarnthochschule, D-42097 Wuppertal. Germany.

The high resolution (0.0027 cm ^l) Fourier transform spectra of the HDSe molecule as ⁸⁰Se monoisotopic and natural materiał were recorded for the first time in the 1500-1900 cm^-1 region where the v\ vibration-rotation band is located. Because accurate information about the rotational structures of both the ground and of the upper vibrational States is still lacking the analysis was begun with the construction of a synthetic spectrum for the v\ band. To realize such a procedurę, the ^vexpanded local modę” model® was used for the construction of isotopic relations bctween spectroscopic paramcters of the H2Se molecule and the corresponding values of its isotopic species HDSe. The latter were used to estimate harmonie frequencies and anharmonic x*_M constants, vibration-rotation o-coefficients, ef-fective rotational and centrifugal distortion constants. and, finally, for the construction of a synthetic spectrum. By this procedurę, a) lines of the recorded spectrum were assigned. and b) band centers, rotational. centrifugal distortion, and resonance i n terać t i on par&me-ters of the (000) and (100) stat.es for the species '^fSeHD, M = 76, 77, 78, 80. and 82, were determined with the help of the combination differences method. The obtained sets of paramcters reproduce both the initially used "mean” values of ground State combination differences. and values of upper State rotation-vibration cnergies. with an accuracy better tlian 0.0001 cm^-1 in generał.

The comparison of the experimentally determined spectroscopic paramcters and the pre-dictions employing the dcrived isotopic relations shows good correlation.

^aO.N. U i.enikon', R.N. Toi.chenoy and Q.-S. Zhu, Spec trockim. Acta. A52, 1829-1841 (1996)