Bulky 2,6-diphenylphenylsulfanyl substituents efficiently inhibit aggregation in phthalocyanines and tetrapyrazinoporphyrazines and control their photophysical and electrochemical properties
Abstract
Octasubstituted zinc, metal-free and magnesium complexes of phthalocyanine and tetrapyrazinoporphyrazine bearing very bulky 2,6-diphenylphenylsulfanyl substituents were synthesized. The substituents efficiently inhibited aggregation of the dyes and only monomers were detected even at a concentration of 200 mu M solution in toluene.
Photophysical data indicated influence of the heavy-atom effect - magnesium complexes were more fluorescent (Phi(F) 0.40-0.51) and zinc complexes produced stronger the singlet oxygen (Phi(Delta) 0.56-0.72) in both series of compounds. The presence of additional nitrogens in tetrapyrazinoporphyrazine core made it substantially more electron deficient when compared with corresponding phthalocyanine analogues. 2,6-Diphenylphenylsulfanyl substituents also increased electron deficient character of the core and influenced the photophysical properties.