A series of benzyl-substituted phthalonitriles, substituted at the 3-, 4-, and 4, 5-positions, underwent varied condensations with phthalonitrile to give a series of protected (monohydroxy-and polyhydroxyphthalocyaninato) zinc (II) derivatives which were readily cleaved to give several hydroxyphthalocyanines (ZnPc)(phthalocyanine phenol analogues). Their efficacy as sensitizers for the photodynamic therapy (PDT) of cancer was evaluated ...