Report and implications of the first observation of C4N2 in laboratory simulations of Titan's atmosphere

C4N2 is an exceptional organic compound in Titan; it is the only one to hav e been detected in condensed phase but not in gas phase. After the descript ion of the delicate C4N2 laboratory synthesis and of the determination of C 4N2 mass spectrum, we report here the first identification of gaseous C4N2 in laboratory simulations of Titan's atmosphere, using our last experimenta l system, based on a N-2-CH4 cold plasma at low temperature and low pressur e. Finally, we discuss the implications of this identification in the frame of remote sensing observations of gaseous C4N2 in Titan's atmosphere. (C) 1999 Elsevier Science Ltd. All rights reserved.