Magnesium(II) phthalocyanine (CAS# 1661-03-6) is a cyanine dye derivative. Photophysical and photodynamic antibacterial properties of this compound have been uncovered when substituted with 2-propoxy, benzyloxy, 3,5-bis(benzyloxy)benzyloxy substituents. The allene derivative of magnesium(II) phthalocyanine has also been used in the preparation of membrane-based optoelectronic devices.