Time-resolved infrared diode laser spectroscopy of the ν1 (C–O stretch) band of the CoCO radical

Abstract

Infrared spectrum of the cobalt carbonyl radical CoCO produced by the 193 nm excimer laser photolysis of cobalt tricarbonyl nitrosyl Co(CO) 3NO was observed by time-resolved diode laser spectroscopy. More than 600 lines were identified as belonging to the ν 1 (C–O stretch) fundamental band, consisting of the Ω = 5 / 2 and 3/2 subbands, and the associated hot bands 1 1 2 , 1 0 1 2 1 1 , 1 0 1 3 1 1 , and 1 0 1 2 2 2 . The 2 Δ i electronic ground state of CoCO was experimentally confirmed. The ν 1 band origins are 1974.172582(93) cm −1 and 1973.53178(14) cm −1 for the Ω = 5 / 2 and 3/2 subbands, respectively. The rotational constant in the ground state was determined as B 0 = 4427.146 ( 50 ) MHz. The centrifugal distortion constant D 0 = 1.1243 ( 68 ) kHz was obtained for the Ω = 5 / 2 substate of the ground state. The equilibrium rotational constant B e = 4435.44 ( 14 ) MHz was derived, together with the vibration–rotation interaction constants.