Eight　novel　piperazine　derivatives　of　metal　(Zn,　Co,　Ni,　Cu)　phthalocyanine　complexes　were　synthesized　from　two　precursors　obtained　by　the　nucleophilic　substitution　of　(N-(2-hydroxyethyl)piperazine)-N　＇-2-ethane　sulfonic　acid　(HEPES)　with　both　3-nitro-phthalonitrile　and　4-nitro-phthalonitrile.　The　complexes　are　characterized　by　IR,　elemental　analysis,　H-1　NMR　and　mass　spectroscopy;　the　UV-vis　absorption　spectra,　rate　of　singlet　oxygen　yields,　fluorescence　spectra　and　quantum　yields　of　the　compounds　are　discussed.　(c)　2007　Published　by　Elsevier　Ltd.