Photophysical and photochemical properties of novel peripherally triethyleneoxysulfanyl substituted monomeric and Si-Si bonded dimeric silicon phthalocyanines

Abstract

Monomeric and Si-Si bonded dimeric silicon(IV) phthalocyanines bearing 4', 7', 10'-trioxaundecylsulfanyl groups were synthesized. These novel phthalocyanine derivatives were characterized by general analysis methods such as FT-IR, MALDI-TOF or HRMS, H-1 NMR and UV-vis electronic absorption. Their aggregation behaviors were described in dimethyl sulfoxide (DMSO). In addition, the photophysical and photochemical properties of these phthalocyanines were also investigated in DMSO to determine potential of these phthalocyanines to acts as photosensitizer for photodynamic therapy (PDT) of cancer. Their high singlet oxygen generation demonstrated their suitability for PDT applications. These peripherally 4', 7', 10'-trioxaundecylsulfanyl substituted silicon(IV) phthalocyanines are promising Type II photosensitizers owing to their favorable singlet oxygen generation capability. In addition, their fluorescence quenching behavior by 1,4-benzoquinone were also studied in DMSO.