Synthesis, characterization and spectroscopic investigation of pyrazinoporphyrazine network polymer-supported metal (II)-based catalysts

Abstract

Chloranil through condensation reaction with vicinal diamine such as diaminomaleonitrile produced heterocyclic monomer, p-benzoquinonebis[2,3-b; 2′,3′-b′]pyrazine-5,6-dinitrile. The tetranitrile monomer was cyclo-tetramerised using lithium/pentanol and acetic acid affording the corresponding tetra p-benzoquinone bis[2,3-b; 2′,3′-b′]pyrazinoporphyrazine)]-based network polymer (2H-Pz). The tetranitril monomer was cyclo-tetramerised using metal salt and quinoline affording the corresponding porphyrazinato-metal II-based network polymers (M-Pz), M = Co, Ni or Cu. Elemental analytical results, IR and NMR spectral data of the prepared molecules are consistent with their assigned formulations. Molecular masses and metal contents of the synthesized polymers proved to be of high molecular masses which confirm the efficiency of tetramerization polymerization and complexation reactions. The prepared pyrazinoporphyrazines were used as efficient catalysts for the oxidation of thiophenol and benzylthiol to their disulfides in the presence of air atmosphere. The results of oxidation of thiophenol and benzylthiol show that after 15 min the maximum yield of the corresponding disulfides reached 95%, 91%, respectively.