15min:
ACCURATE DETERMINATION OF THE GROUND STATE CONSTANTS, INCLUDING A0 AND DK0, OF D3Si35Cl.

A. CEAUSU, G. GRANER, Laboratoire de Physique Moléculaire et Applications, CNRS, Bât. 350, Campus d'Orsay, F-91405 Orsay Cédex, France; E. B. MKADMI AND H. BÜRGER, , Anorganische Chemie, FB 9, Universität-Gesamthochschule, D-42097 Wuppertal, Germany.

In a previous studyof monoisotopic D3Si35Cl, the analysis of the fundamental bands nu3 and nu6, linked by a Coriolis resonance, was reported. New Fourier transform infrared spectra of this compound were recorded in the 500 and 1000 cm-1 regions. The first purpose was to obtain accurate ground state constants. The 'normal' G.S. constants B0, DJ0, and DJK0 were deduced from GSCD. As for the constants A0 and DK0, they were obtained by the now well-established method of combining data from the fundamental nu6, the overtone (2nu6)\mp2 and the hot band (2nu6)\pm2-(nu6)\pm1. Special care was taken to correct calibration differences between the two spectral regions. This was done by checking closed loops such as nu3, 2nu3, and 2nu3 - nu3 on one hand or nu6,(2nu6)0 and (2nu6)0 - nu6 on the other hand. The values obtained are A0 =1.427830 cm-1 and DK0=5.36× 10-6 cm-1 (provisional values). Some sextic H constants could also be determined. In a second stage, the upper state energies of (2nu6)\pm2, (2nu6)0, 2nu3 and nu3 + nu6 were fitted together to obtain the upper state constants. Note that, due to the weakness of the nu3 + nu6 band, the hot bands nu3 + nu6 - nu3 and nu3 + nu6 - nu6 were used instead.