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

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.