Abstract: The cyanogen di-N-oxide molecule (ONCCNO) has been generated in high yield from in situ flow pyrolysis reactions of gaseous dichloroglyoxime or dibromofuroxan precursors and studied for the first time in the gas phase. This structurally novel transient species is characterized by He1 photoelectron, HeI/HL, photoionization mass, and mid- infrared spectroscopies. To complement the experimental aspects, an assessment of the ...