15min:
TIME RESOLVED INFRARED DIODE LASER SPECTROSCOPY OF THE nu1 BAND OF THE CoCO RADICAL PRODUCED BY THE ULTRAVIOLET PHOTOLYSIS OF Co(CO)3 NO..

TOSHIHIDE HIKIDA, SEIKI IKEDA, KEIICHI TANAKA AND TAKEHIKO TANAKA, Department of Chemistry, Faculty of Science, Kyushu University 33, Hakozaki, Higashiku, Fukuoka 812-8581, Japan.

Rovibrational transitions of the nu1 band (C-O stretch) of the CoCO radical produced by the ultraviolet photolysis of Co(CO)3NO 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. ~ More than 140 absorption lines were assigned to the Omega = 5/2 spin component of the nu1 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 nu0 and the rotational constant B, were derived from observed transitions. Hot band lines originated from the nu2 (Co-C-O bending) and nu3 (Co-C stretch) vibrational excited states were observed. Absorption lines for the nu2 hot band were split into two components because of the vibronic interaction between the nu2 state and other nearby electronic excited states. The effective equilibrium rotational constant Be and the vibration rotation constants, alpha1, alpha2 and alpha3 were determined from the analysis of the fundamental band and hot bands.