How rapidly does the SH radical react with N2O?

The reaction of SH radical with N2O was investigated by using two complemen tary experimental methods: (a) a pulsed photolysis apparatus where SH was d etected via laser-induced fluorescence and (b) a discharge flow tube where SH was detected via chemical ionization mass spectrometry. The rate coeffic ient for this reaction, k(1), was found to be less than 5 x 10(-16) cm(3) m olecule(-1) s(-1) at 298 K, in contrast to the large value reported in the literature [Ravichandran; et al. Chem. Phys. Lett. 1994, 217, 375-379]. Sec ondary reactions were deduced to be unimportant in our system. Some possibl e reasons for the previously reported high value are presented. The low val ue of k(1) makes the oxidation of SH by N2O and removal of N2O by SH unimpo rtant in the earth's atmosphere.