THE OPTICAL AND OPTICAL STARK SPECTRUM OF IRIDIUM MONOCARBIDE AND MONONITRIDE/

Supersonic molecular beam samples of iridium monocarbide IrC and iridi um mononitride IrN were generated using a laser ablation/reaction sour ce and characterized using high resolution (Delta nu<30 MHz FWHM) lase r induced fluorescence spectroscopy. This is the first identification of gaseous IrN. Numerous strong band systems in the 18 800 to 14 360 c m(-1) spectral range were assigned as the (upsilon',0) progression of the A (1) Pi-X (1) Sigma(+) band system of IrN. The (1,0) and (0,0) ba nds were analyzed to produce a set of fine and hyperfine parameters. T he electric field induced effects on the R(0) line of these bands were analyzed to produce permanent electric dipole moments: A (1) Pi(upsil on = 0) 2.78(2) D, A (1) Pi(upsilon=1) 2.64(2) D, X (1) Sigma(+)(upsil on=0)=1.66(1) D. The (0,0) band of the D-2 Phi(7/2)-X (2) Delta(5/2) s ystem of IrC was recorded and analyzed to produce a set of fine and hy perfine parameters. The electric field induced effects on the R(2.5) b ranch feature were analyzed to produce permanent electric dipole momen ts: D (2) Phi(7/2)(upsilon=0) 2.61(6) D and X (2) Delta(5/2)(upsilon=0 ) 1.60(7) D. Plausible electronic configurations consistent with the e xperimental observations are given. (C) 1996 American Institute of Phy sics.