Gas infrared spectra, assignments, and absolute IR band intensities of C4N2 in the 250–3500 cm−1 region: implications for Titan's stratosphere

The IR spectrum of gaseous dicyanoacetylene, NC-C equivalent to C-CN, is studied in the 3500-220 cm(-1) range, employing Fourier transform spectroscopy. A total of 17 bands are analyzed and assigned. The absolute intensity is determined and the associated uncertainty is estimated for each of the bands. The resulting data are used to study the detectability of gaseous C4N2 in Titan's atmosphere. In particular a better estimate of the upper limits of its abundance in Titan's atmosphere is obtained when our results are used to reanalyse Voyager IRIS infrared spectra. (C) 1997 Published by Elsevier Science B.V.