Effects of the degree of substitution on the physicochemical properties and photodynamic activity of zinc and aluminum phthalocyanine polycations

A series of zinc and aluminum phthalocyanines containing 3–8 pyridiniomethyl or cholinyl substituents on average were synthesized. As the number of cation substituents increased, in aqueous solutions, the aggregation ability of phthalocyanines decreased, while the quantum yields of fluorescence and singlet oxygen generation increased. The photodynamic inactivation of coliform bacteria sensitized by zinc and aluminum phthalocyanine polycations with an increase in the substitution degree became more effective.