INFRARED-LASER SPECTROSCOPY OF JET-COOLED CHROMIUM HEXACARBONYL IN THE 5-MU-M REGION

The infrared spectrum of chromium hexacarbonyl near 2000 cm(-1) has be en rotationally resolved by cooling in a supersonic jet. Spectroscopic parameters have been obtained for the weakly perturbed nu(6) carbonyl stretching fundamental of Cr-52((CO)-C-12-O-16)(6) and the unperturbe d, overlapped nu(6) fundamentals of the isotopomers Cr-50,Cr-53,Cr-54( (CO)-C-12-O-16)(6). A likely candidate far the perturbing state is pro posed. Observation of a perpendicular band of the symmetric-top molecu le Cr-52((CO)-C-12-O-16)(5)(CO)-C-13-O-16 in the same region permitted an improvement in the accuracy of the bond lengths of gas-phase chrom ium hexacarbonyl. All the isotopomers were observed in natural abundan ce. (C) 1994 Academic Press, Inc.