Knowledge Bank

The electronic emission spectrum of YN has been observed in the 2.3-2.6 $\mu$ spectral region using a Fourier transform spectrometer. The bands were excited in a yurium hollow cathode lamp in the presence of a trace of molecular nitrogen. The observed bands, with origins at 3882.7625(4), 4229.0457(3), 4528. 6562(46), 4798.5145(13), 5049.4429(20) and 5281.2129(27)$ cm^{-1}$, have been assigned as the 0-0, 1-1, 3-3, 4-4 and 5-5 vibrational bands, respectively, of the $A\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma +-X\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}\Sigma +$ electronic transition. The principal equilibrium constants for the ground state obtained from this analysis are {\AA} and the corresponding excited state values are $Be\prime =0.42311(30)cm-1$ and $re=1.81477(64)$ {\AA}. This work represents the first observation of the YN molecule.