Knowledge Bank

High resolution optical spectroscopic studies of gas-phase chromium mononitride, CrN, and vanadium mononitride, VN, using molecular beam techniques have been performed. The $Ree(0.5)$ branch feature of the $(0,0)A4\Pi 3/2-A4\Sigma 1/2-$ band system for $\mathrm{<mrow\; data-mjx-texclass="ORD">52</mrow>}CrN$ was recorded as a function of the static electric field in the range $1.2-2.0$ kV/cm. The resultant Stark shifts were analyzed to produce permanent electric dipole moments of 2.31(4)D and 5.41(2)D for the ground $X4\Sigma 1/2-$ and excited $A4II3/2$ states, respectively. The $Pe,F\prime \prime =2.5$ feature of the $(0,0)D3\Pi 0-X3\Delta 1$ band system for $\mathrm{<mrow\; data-mjx-texclass="ORD">51</mrow>}V14N(I=3.5)$ was also recorded as a function of static electric field in the range .4 - 1.2 kV/cm. The permanent electric dipole moments derived from a least squares analysis of the Stark shifts were 3.07(1)D for the ground $X3\Delta 1$ state and 6.15(3)D for the excited $D3\Pi 0$ state. The $\mathrm{<mrow\; data-mjx-texclass="ORD">52</mrow>}Cr14N(I=1)$ hyperfine structure was determined from the analysis of 12 components of the lowest pure rotational levels using the pump/probe microwave-optical double resonance technique. The resulting parameters are (in $cm-1)B\prime \prime =.62387360(74),B\prime =.6060(1),\gamma \prime \prime =.0070050(13),\lambda \prime \prime =2.611151(16),eqQ0(14N)=-.000025(10),bF(14N)=.0000062(34)$ and $c(14N)=-.000151(92)$. Comparisons to other experimental work and theoretical bonding models are $givena$. Observed trends amongst the early transition metals will be discussed.