ALPHA-2-PI-U-]CHI-2-PI-G EMISSION AND THE PHOTOELECTRON-SPECTRUM OF DICYANODIACETYLENE RADICAL CATION

Gas phase emission spectrum of dicyanodiacetylene radical cation has been detected. The band system which lies in the 630-770nm wavelength region was separated from the overlapping emission bands of the cyanogen radical by recording time resolved spectra. The He(Iα) photoelectron spectrum of dicyanodiacetylene is also presented and the inferred ionization energies, vibrational frequencies and assignments are given. From the latter data the emission spectrum is assigned as the à 2Πu→ X̃ 2Πg electronic transition of dicyanodiacetylene radical cation. The frequencies of the four Σg +vibrational fundamentals for the cationic ground state have been deduced from the emission spectrum. © 1979 American Institute of Physics.