W. BRYAN LYNCH, Department of Chemistry, University of Evansville, Evansville, IN 47722; HANS A. BECHTEL, ADAM H. STEEVES, JOHN J. CURLEY AND ROBERT W. FIELD, Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139.
The Ã1A'' 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 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-1 on the excited state energy.