Novel polymeric phthalocyanines bridged flexible 1,5-pentanedithiol unit for metal ions extraction: synthesis, characterization and evaluation

A novel bisphthalonitrile 5,5′-(pentane-1,5-diylbis(sulfanediyl))bis(4-((2-aminophenyl)thio)phthalonitrile) 2 was synthesized by a nucleophilic aromatic substitution of chloro atom of 4-(2′-aminophenyl sulfanyl)-5-chloro-benzene-1,2-dicarbonitrile 1 with dithiol functions of pentane-1,5-dithiole. The synthesis of polymeric phthalocyanine complexes 3 and 4 by cyclotetramerization of bisphthalonitrile derivative 2 were accomplished in the presence of appropriate metal salt in a Schlenk tube containing quinoline under nitrogen atmosphere. The investigation of metal-ion binding properties of bisphthalonitrile 2 and polymeric zinc(II) phthalocyanine 4 was performed by using liquid–liquid extraction procedure for 2 and solid–liquid extraction procedure for 4. Polymeric zinc(II) phthalocyanine 4 was found to extract Ag(II) and Hg(II) with high efficiency. The novel compounds were characterized by a combination of elemental analysis and 1H NMR, 13C NMR, IR, and MS spectral data.