A laser-induced fluorescence study of the visible spectrum of rhodium monoxide

A first analysis of an electronic spectrum of RhO is presented. The molecular species has been produced in a jet-cooled molecular beam following reaction in a laser ablation plasma. Laser excitation spectra have been recorded between 600 and 640 nm at 200 MHz resolution. Two transitions have been identified of 2Pi(r)(a)-X-4 Sigma(-) (b) type and six subbands have been rotationally analyzed, four being (0,0) components. Molecular parameters for the X(4)Sigma(-) state are B-0 = 0.41320 cm(-1), lambda(0) = -0.5733 cm(-1), gamma(0) = -0.10276 cm(-1), and r(0) = 0.1717 nm. An analysis of the hyperfine structure involving the Rh-103 nucleus has been made. It shows that the around state of RhO conforms to Hund's coupling case b(betaJ) with b = -0.0203 cm(-1). Hyperfine effects in the excited states are negligible. (C) 2002 Elsevier Science (USA).