Self‐Assembled Azaphthalocyanine Dimers with Higher Fluorescence and Singlet Oxygen Quantum Yields than the Corresponding Monomers
In this work, we describe diethylamino-substituted metalazaphthalocyanines that form self-assembled J-dimers in noncoordinating solvents. The dimers are formed by the coordination of the free electron pair of one diethylamino group with the central metal of the adjacent molecule. The addition of pyridine leads to monomerization and considerable quenching of fluorescence and singlet oxygen formation as a result of intramolecular photoinduced singlet electron transfer (PET). PET is efficiently inhibited in dimers; therefore, dimers have higher fluorescence and singlet oxygen quantum yields than the corresponding monomers.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)