Rotationally resolved A2Πu←X 2Πg electronic transition of NC6N+

The rotationally resolved A2Πu←X2Πg electronic origin band spectrum of dicyanodiacetylene cation, NC6N+, has been recorded in the gas phase using frequency-production double modulation spectroscopy in a liquid nitrogen cooled hollow cathode discharge and cavity ring down spectroscopy in a supersonic plasma. The analysis of the complementary results provides accurate molecular parameters for the two spin-orbit components in both electronic states.