Aziridines I react with trifluoromethylhypofluorite at − 40°C to produce mixtures of 1-(aziridine)carbonylfluoride II and 1-fluoroaziridine III, the proportions of which depend on steric effects. Several compounds II react with starting materials to give 1, 1′-(carbonyl)bisaziridines IV. Most compounds II and all compounds IV are isolated. Chemical properties and ir and nmr data of II, III, IV are