Knowledge Bank

Elucidating the structure and function of the chemically pervasive transition metal-carbon bond is a problem of both fundamental and applied scientific interest. Recent insight into the nature of the metal-carbon bond has been due to high-resolution gas-phase spectroscopy of the diatomic monocarbides, where measurement of permanent electric dipole moments and hyperfine structure are particularly informative. Ruthenium monocarbide has garnered recent $interestabcdef$ due to its ease of production, intense visible electronic transitions and large magnetic hyperfine structure. We report on the investigation of the $(0,0)\{12.7\}3\Pi 2-\{0.1\}3\Delta 3$ and $(0,0)13.93\Pi 1-\{0.9\}3\Delta 2$ band systems using high-resolution laser induced fluorescence spectroscopy. Stark shifts of the $\mathrm{<mrow\; data-mjx-texclass="ORD">102</mrow>}RuC$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">104</mrow>}RuC$ isotopomers were analyzed to produce the magnitude of the permanent electric dipole moments for the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Delta 3,\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Delta 2,\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi 2$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi 1$ states. The measured moments prompt a discussion of the electronic structure and bonding in the $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Delta$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Pi$ electronic states. Dipole moment trends are most informative when coupled to molecular orbital correlation diagrams. The measured dipole moments can be used as true benchmarks for rigorous electronic structure calculations. A comparison with isovalent FeC is $made.g$