Knowledge Bank

We have generated MgNC in supersonic free jet expansions, and measured the laser induced fluorescence excitation spectra of the C-N stretching vibronic bands of the $A~\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi -X~\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma +$ transition. Rotational analysis yields the molecular constants of the vibronic levels, (1,0,0) and (1,0,1), in the $A~\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ state. The vibronic levels, (0,0,0), (0,1,0), and (0,0,1), were already analyzed by $WrightandMillera$. We can not find any anomalies in the constants of the C-N stretching vibronic levels, while they are predicted to be lying above the barrier of the isomerization reaction pathway, MgNC $\leftrightarrow$ MgCN, on the $A~\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ state. On the basis of the molecular constants obtained, we discuss the fine structures of both the ground $X~\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma +$ and excited $A~\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ states.