INFRARED-LASER SPECTROSCOPY OF JET-COOLED CYCLOPENTADIENYL COBALT DICARBONYL

The infrared absorption spectrum of jet-cooled eta(5)-cyclopentadienyl cobalt dicarbonyl, CpCo(CO)(2), in the carbonyl-stretching region nea r 5 mu m has been recorded using tunable diode laser spectroscopy. The two absorption bands have highly contrasting structures. The rotation al structure is severely overlapped and could not be assigned, but the band origins are estimated to be 2047.41 +/- 0.05 cm(-1) (A(1) band) and 1999.0 +/- 0.2 cm(-1) (B-2 band). The molecule is a highly asymmet ric top, and simulations suggest congested spectra even if internal ro tation is neglected. (C) 1997 Elsevier Science B.V.