Copper complex of an iminodioxabicyclo[3.3.1]nonane pendant ligand: the first example of iminodioxocin bridgehead nitrogen coordination.

The pentadentate N4O amine-imine-naphthol ligand (HL(D)) containing rigid 8,16-imino-8H,16H-dinaphtho[2,1-b:2,1-f][1,5]dioxocin is formed preferentially, under visible light irradiation conditions, instead of the product H3L, expected from imidazolidine ring formation. A strained chelate bite enforces the first bridgehead nitrogen coordination to a copper(II) ion from the bicyclic iminodioxocin part of the ligand as shown by X-ray crystallography.