A Hund's case (a) analysis of the [18.8]3Φi-X3Φi electronic transition of CoF

We have recently observed a weak electronic subband near 513 nm in the electronic spectrum of cobalt monofluoride. A rotational analysis has led to its identification as a (3)Phi (3)-X(3)Phi (4) subband where Delta Sigma = -1 and Delta Omega = -1. This critical datum has been used in combination with our previously published data (A. G. Adam et al., 1994, Chem. Phys. Lett. 230, 82) to obtain a Hund's case (a) analysis for the [18.8](3)Phi (i)-X(3)Phi (i) transition of CoF. The spectroscopic constants and electronic states of CoF are compared to those of CoH and Co+. Two distinct excited (3)Phi electronic state vibrational progressions have also been identified in the CoF spectra. The band positions and rotational constants have been used to calculate equilibrium constants for the excited (3)Phi states. The two electronic transitions are identified as the K(3)Phi (i)-X(3)Phi (i) and L(3)Phi (i)-X(3)Phi (i) transitions based on comparisons with CoH. (C) 2001 Academic Press.