Zinc porphyrin with phenoxy-bridged pentacoordinate bis(8-hydroxyquinaldinate)gallium lateral pendants: synthesis and photophysical characterization

This communication reports the synthesis of polymetallic species formed by a zinc-tetraphenolporphyrinate core (ZnTPP(OH)4, 1) and peripheral gallium-quinaldinate image fragments. The photophysical analysis of 1 and of the model compound image, R, shows an appreciable overlap between the absorption spectra of 1 and the emission spectra of R, suggesting the presence of a donor–acceptor energy-transfer process. Contrarily, the obtained results indicated that energy transfer does not occur, hence these polymetallic complexes work as double emitting species, for which the colour of luminescence depends on the excitation energy.