Synthesis, photophysical and photochemical properties of highly soluble phthalocyanines substituted with four 3,5-dimethylpyrazole-1-methoxy groups

Abstract

The synthesis and characterization of new peripherally tetra-3,5-dimethylpyrazole-1-methoxy substituted metal-free ( 4), zinc ( 5), nickel ( 6), cobalt ( 7), copper ( 8) and lead ( 9) phthalocyanines are described for the first time in this study. The photophysical (fluorescence quantum yields and fluorescence lifetimes) and photochemical (photodegradation and singlet oxygen quantum yields) properties of metal-free ( 4), zinc ( 5) and lead ( 9) phthalocyanines are studied in dimethylsulfoxide (DMSO). Nickel ( 6), cobalt ( 7) and copper ( 8) phthalocyanines ( 6–8) did not evaluate for this purpose due to transition metal and paramagnetic behavior of central metals in the phthalocyanine cavity. The fluorescence quenching behavior of metal-free ( 4), zinc ( 5) and lead ( 9) phthalocyanines are also investigated. The fluorescence emissions of these phthalocyanines are effectively quenched by 1,4-benzoquinone in DMSO.