Targeted as an example of a compound composed of a carbon atom together with two stable neutral leaving groups, 7-isocyano-7-azadibenzonorbornadiene, CN 2 A (1, A = C 14 H 10 or anthracene) has been synthesized and spectroscopically and structurally characterized. The terminal C atom of 1 can be transferred: mesityl nitrile oxide reacts with 1 to produce carbon monoxide, likely via intermediacy of the N-isocyanate OCN 2 A. Reaction of 1 with [RuCl 2 (CO)(PCy 3 ) 2 ] leads to [RuCl 2 (CO)(1)(PCy 3 ) 2 ] which decomposes unselectively: in the product mixture, the carbide complex [RuCl 2 (C)(PCy 3 ) 2 ] was detected. Upon heating in the solid state or in solution, 1 decomposes to A, N 2 and cyanogen (C 2 N 2 ) as substantiated using molecular beam mass spectrometry, IR and NMR spectroscopy techniques.