Reaction with NOCI

The reaction of the recently reported compound [SF2NCO] [AsFft] with NOCI takes place through nucleophilic attack of Cl" at the C atom of the isocyanate group, and results in the formation of chloroformyl sulphur difluoride imide (5). 

The nitroxide [CFj-CF(S0 F)],N-0 has been encountered in work on the nitroso-compound CFj-CF(NO)-SOsF, obtainable via reaction of per-fluoropropene with sulphur trioxide followed by hydrolysis of the resultant sultone to CFg-CHF-SOjF and treatment of this with NOCI in the presence of a tertiary amine [see p. 282, ref. 456, and item (vii) below]. 

Finlayson-Pitts, B. J., Reaction of N02 with NaCl and Atmospheric Implications of NOCI Formation, Nature, 306, 676-677 (1983). 

NO has at least as great an inhibiting effect on the reaction sensitised by NOCI as on the unsensitised reaction. This indicates that the effect of NO is to increase the rate of termination rather than having any effect on the initiation. The mechanism suggested is in agreement with these observations and also accounts for the inhibiting effects of inert gases. 

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