Knowledge Bank

The \ {A}$\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}A\prime \prime$ state of isocyanogen is observed using photofragment fluorescence excitation spectroscopy (PHOFEX). The spectra are highly congested, but progressions likely due to the Franck-Condon active C-N-C excited state bend are evident. Linewidth measurements indicate that the excited state lifetime is $<$ 10 ps. These measurements are consistent with previous {\em ab initio} calculations, which predicted a bent excited state and a short lifetime due to predissociation. Although we do not believe the origin band is observed, we place an upper limit of 42523 cm$\mathrm{<mrow\; data-mjx-texclass="ORD">-1</mrow>}$ on the excited state energy.