Further investigations of the ClO rotational spectrum

Pure rotational transitions of the chlorine monoxide radical have been obse rved up to v = 2 in the X-1 (2)Pi (3/2) and X(2)(2)Pi (1/2) states and tran sitions of the (ClO)-Cl-35-O-18 isotopomer have been observed in natural ab undance. Additionally, rotational transitions for levels up to J' = 115/2 h ave been measured in the far infrared. These data have been merged with the existing microwave, submillimeter, and high-resolution infrared transition frequencies and fit simultaneously with a set of isotopically independent parameters. Isotopic substitution of both the Cl and O atoms has enabled th e first determination of the electron spin-rotation constant gamma = -296.0 (43) MHz as well as the Born-Oppenheimer corrections to the rotational cons tants. (C) 2001 Academic Press.