A Rotational and Hyperfine Analysis of the [14.0]2Σ+–X2Σ+Band System of Cobalt Monocarbide

✍ Scribed by A.G. Adam; J.R.D. Peers

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 245 KB
• Volume: 181
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1996.7147

✦ Synopsis

The cobalt monocarbide molecule has been produced by laser ablation of a cobalt rod in the presence of 1.5% methanol in a helium carrier gas. The mixture was expanded into a vacuum, yielding a free jet with T rot Ç 30 K. Low resolution laser-induced fluorescence studies showed the [14.0] 2 S / -X 2 S / band system as a long vibrational progression between 500 and 720 nm. Several vibrational bands were analyzed at high resolution; least squares fitting of the data led to the determination of rotational and hyperfine constants for both states. The X 2 S / state is best described by a Hund's case (b bS ) coupling scheme, while the [14.0] 2 S / state conforms to case (b bJ ). Analysis of the hyperfine parameters indicates that the X 2 S / state arises from a valence (8s) 2 (3p) 4 (1d) 4 (9s) 1 electronic configuration and that the [14.0] 2 S / state originates from a (8s) 1 (3p) 4 (1d) 4 (9s) 2 configuration. The vibrational levels of the [14.0] 2 S / state appear to be perturbed by other nearby states; this is reflected in unusual distortions in the spin-rotation parameters from one vibrational level to the next. The effects of the perturbations are also observed in the sign and magnitude of the hyperfine dipolar interaction parameters of the [14.0] 2 S / state, and effects are also observed on the Fermi contact and electric quadrupolar parameters.