The new tetrakis-(6-oxyquinoline)phthalocyaninato zinc (II) (5), octakis-(6-oxyquinoline) phthalocyaninato zinc (II) (6) and their quaternized derivatives (5a and 6a) have been synthesized and characterized. Photophysical and photochemical properties of 6-oxyquinoline appended zinc (II) phthalocyanines are investigated in dimethylsulfoxide (DMSO) for both the non-ionic (5 and 6) and quaternized ionic (5a and 6a) complexes and in phosphate buffered solution (PBS) for quaternized ionic complexes. General trends are described for photodegradation quantum yields, fluorescence quantum yields and fluorescence lifetimes as well as singlet oxygen quantum yields of these compounds. In this study, the effects of the position and number of the substituents, and quaternization of the substituents on the photophysical and photochemical parameters of the zinc (II) phthalocyanines are also reported. A spectroscopic investigation of the binding of the quaternized ionic zinc (II) phthalocyanine complexes to bovine serum albumin (BSA) is also presented in this work. (C) 2010 Elsevier B.V. All rights reserved.