"Carbon dichloride": dihalocarbenes sixty years after Hine.

We describe new syntheses of dichlorodiazirine, difluorodiazirine, and chlorofluorodiazirine. From these precursors, laser flash photolysis enables the generation of CCl(2), CF(2), and CClF. We describe the formation and chemistry of bromodichloromethide carbanion from CCl(2), the ambiplilicity of CCl(2), the complexation of CCl(2) by aromatic ethers, and the kinetics and activation parameters attending the additions of CCl(2), CF(2), and CClF to several alkenes.