The photochemistry and photophysics of a series of non-peripherally substituted zinc phthalocyanines

Abstract

Photophysical and photochemical measurements have been made on a series of novel non-peripherally octa(alkyl-substituted) zinc phthalocyanines. Fluorescence quantum yields and lifetimes, triplet quantum yields and lifetimes and singlet delta oxygen quantum yields were measured in 1% v/v pyridine in toluene. The effects of alkyl substituents and increasing chain length relative to the unsubstituted parent molecule, zinc phthalocyanine (ZnPc), are discussed. ZnPc with alkyl substituents of chain length 5-15 carbons exhibited similar absorption and emission maxima (704 nm and 718 nm respectively) with the molar absorptivity of the Q-band approximately 10(5) M(-1) cm(-1). The series of compounds also exhibited triplet quantum yields of 0.78-0.84 and singlet oxygen quantum yields of 0.67-0.71.