Electronic spectroscopy of rhodium mononitride

We report the first observation of gas-phase electronic spectra for rhodium mononitride. The RhN molecules have been produced in the reaction of laser-ablated rhodium metal with ammonia. Many vibronic bands have been studied in the 400-700 nm region using laser-induced fluorescence. Rotational analyses of the stronger of these, together with excited state lifetime measurements and (RhN)-N-14-(RhN)-N-15 isotopic shifts, identify three electronic systems in the region: [15.1]1-X(1)Sigma(+), [19.5]0(+)-X(1)Sigma(+), and [22.4]0(+)-X(1)Sigma(+) with (0, 0) bands near 15 071, 19 489, and 22 385 cm(-1), respectively. The (1)Sigma(+) symmetry for the ground state agrees with theoretical predictions. Dispersed fluorescence spectra have been recorded which reveal the presence of electronic states at T = 553, 1740, and 3920 cm(-1). (C) 2000 Academic Press.