Synthesis and photophysical properties of silicon(IV) tetrapyrazinoporphyrazines axially substituted with ethylene glycol chains as potential photosensitizer

Abstract

Photodynamic therapy involves administration of a tumor-localizing photosensitizer, which may require metabolic conversion, followed by activation of the photosensitizer with light of a specific wavelength. In this paper, we report the design and synthesis of silicon(IV) tetrapyrazinoporphyrazines derived from 5,9,9-trimethyl-5,6,7,8-tetrahydro-5,8-methanoquinoxaline-2,3-dicarbonitrile. The HO-(CH2CH2O)(n)-CH3 groups were introduced at axial positions to give a specific functionality. In particular, poly(ethylene glycol) groups were expected to increase water solubility without changing the lambda(max).