Synthesis, Characterization, Crystal and Molecular Structure of 1,5‐Dihydro‐2 H ‐cyclopenta[1,2‐ b :5,4‐ b′ ]dipyridin‐2‐imine

The reaction of 1,5‐dihydro‐2 H ‐cyclopenta[1,2‐ b: 5,4‐ b′ ]dipyridin‐2‐one ( 3 ) with an alkylamine (butylamine, hexylamine or ethylenediamine) yields, quite unexpectedly and in the absence of catalyst, the novel compound 1,5‐dihydro‐2 H ‐cyclopenta[1,2‐ b: 5,4‐ b ′]dipyridin‐2‐imine ( 4 ) as the sole, analytically pure, solid product, which was fully characterized. The structure of 4 was unequivocally solved by single‐crystal X‐ray‐diffraction analysis. The compound crystallizes in a monoclinic cell (space group P 2 1 / c ), with two molecules in the asymmetric unit, held together by intermolecular H‐bonds. Compound 4 could be interesting as a bi‐ or even tridentate ligand, and exhibits a strong fluorescence upon excitation at 310 nm. A mechanism, based on the observed CN bond cleavage, is proposed.