JOSHUA B. HALPERN AND YUHUI HUANG, DEPARTMENT OF CHEMISTRY, HOWARD UNIVERSITY, WASHINGTON, DC 20059.
A new analysis is presented for the VUV C2N2 C1Bu - X1g+ transition. Contrary to previous studies this is shown to be a linear to bent transition with a trans-bent C1Bu excited electronic state. The electronic origin is at 59,848 cm-1, about 550 cm-1 lower than previously thought . Vibrational bands between 170 and 145 nm are assigned. The C1Bu symmetric CN stretching frequency, 1, is as previously noted 2050 \b+ 20 cm-1. It has been possible to assign four of the five other vibrational frequencies. The symmetric CC stretching frequency, 2, is 926 \b+ 20 cm-1. The trans-bending vibrational frequency, 3, is 532 \b+ 10 cm-1, the torsional bending frequency, 4, is 110 \b+ 10 cm-1 and the cis bending frequency, 6, is 140 \b+ 10 cm-1. Anharmonicities have also been determined for the various vibrational modes.