A magnesium porphyrazine possessing isophthaloxybutylsulfanyl substituents in the periphery was synthesized and subjected to various photophysical studies, including optical absorption and emission measurements. Moreover, synchronous fluorescence spectra were recorded and a contour three-dimensional map of the excitation-emission of the studied porphyrazine was obtained. The porphyrazine macrocycle exhibited interesting solvatochromic effects in many different solvents. Upon excitation with visible light, it generated singlet oxygen with a low quantum yield, therefore when it was encapsulated in liposomes it exhibited no photocytotoxicity in the in vitro study on human carcinoma LNCaP cell line.