OPTICAL STARK SPECTROSCOPY OF MOLYBDENUM CARBIDE, MoC

{I. Shim and K. A. Gingerich \textit{J. Chem. Phys.Author Institution: Department of Chemistry and Biochemistry,; Arizona State University, Tempe, AZ 85287-1604High resolution optical spectroscopy has been used to study a molecular beam of molybdenum carbide, MoC. The $R_{e}(0) (\nu=18612.978 \wn)$ and $Q_{fe}(1) (\nu=18611.872 \wn)$ branch features of the (0,0) $[18.6]^{3}\Pi_{1}-X^{3}\Sigma^{-}$ system of $^{98}MoC$ were analyzed using Stark spectroscopy. Electric field induced splitting in the laser induced fluorescence (LIF) spectra was analyzed to measure permanent electric dipole moments of 2.69(2)D and 6.32(20)D for the $[18.6]^{3}\Pi_{1}$ and $X^{3}\Sigma^{-}$ states, respectively. Excited state hyperfine structure has been observed for the first time in $^{95}MoC$ and $^{97}MoC$. Experimental results will be compared to theoretical predictions, } \underline{\textbf{106}}, 8093 (1997).} and the electronic structure will be discussed using a molecular orbital correlation model. The MoC dipole moments will be compared with those of other transition metal monocarbides. An interesting observation is that the \textit{ab initio} calculations for second row transition metal monocarbides are more reliable than predictions for the first row carbides