Porphyrins hydroquinone-appended

A different approach for the construction of divergently linked donor-acceptor complexes was reported by D Souza.Hydroquinone-appended porphyrin 131 as a photodonor was prepared to associate with a quinone via double hydrogen bonding. Upon addition of 2,6-dichloro-3,5-dicyano-/ -benzoquinone, the fluorescence of zinc porphyrin was considerably quenched in benzonitrile. 

The zinc porphyrin P-2 with an appended hydroquinone can form complexes with quinones via H-bonds and charge-transfer interactions. In such complexes, PET from the porphyrin to the quinone is possible, and efficient fluorescence quenching was indeed observed upon binding with substituted benzoquinones, naphthaquinones and anthraquinones. 

P-3, consisting of a free-base porphyrin with an appended quinone, is weakly fluorescent due to PET. Complexation with substituted hydroquinones induces fluorescence enhancement because of the unfavorable conditions for PET from the porphyrin to the quinone-hydroquinone entity. 

---

See also in sourсe #XX -- [ ]

---