TIME RESOLVED INFRARED DIODE LASER SPECTROSCOPY OF THE $\nu_{1}$ BAND OF THE CoCO RADICAL PRODUCED BY THE ULTRAVIOLET PHOTOLYSIS OF $Co(CO)_{3}NO$.

$^{a}$M. Zhou, L. Andrews, J. Phys. Chem. A 102, 10250 (1998).Author Institution: Department of Chemistry, Faculty of Science, Kyushu University 33, HakozakiRovibrational transitions of the $\nu_{1}$ band (C-O stretch) of the CoCO radical produced by the ultraviolet photolysis of $Co(CO)_{3}NO$ were observed in $1949-1991 cm^{-1}$ region by the time resolved infrared diode laser spectroscopy. The electronic ground state was confirmed to be $X^{2}\Delta_{i}$ by the analysis as predicted by the density functional theory calculation. $^{a}$ More than 140 absorption lines were assigned to the $\Omega = 5/2$ spin component of the $\nu_{1}$ fundamental band in the $X^{2}\Delta_{i}$ state. No lines of the $\Omega = 3/2$ component were observed due to the large spin-orbit interaction constant A $(-500 cm^{-1})$. Effective molecular constants for the $\Omega = 5/2$ spin component, including the band origin $\nu_{0}$ and the rotational constant B, were derived from observed transitions. Hot band lines originated from the $\nu_{2}$ (Co-C-O bending) and $\nu_{3}$ (Co-C stretch) vibrational excited states were observed. Absorption lines for the $\nu_{2}$ hot band were split into two components because of the vibronic interaction between the $\nu_{2}$ state and other nearby electronic excited states. The effective equilibrium rotational constant $B_{e}$ and the vibration rotation constants, $\alpha_{1}, \alpha_{2}$ and $\alpha_{3}$ were determined from the analysis of the fundamental band and hot bands