Convenient synthesis of novel unmetalled and metallophthalocyanines bearing coumarin derivatives: synthesis, characterization, aggregation behaviors and antimicrobial activity

Abstract

Metal-free and metallophthalocyanines 3–10 carrying four coumarins group on the periphery were prepared by cyclotetramerisation of a new precursor, namely 4-(4-Methyl-2-oxo-2H-chromen-7-yloxy)-phthalonitrile 1 and 4-(2-Oxo-2H-chromen-7-yloxy)-phthalonitrile 2 in the presence of the corresponding divalent metal salts (Zn (II), Cu(II) and Co(II). The aggregation behaviors of the unmetalled 3 and metallophthalocyanines 5 were investigated. The novel phthalonitrile derivatives 1–2 were synthesized by the reaction between 4-nitrophthalonitrile with 7-hydroxy-4-methylcoumarin and 7-hydroxycoumarin respectively in polar aprotic solvents (DMF or DMSO) in the presence of dry K2CO3 as base catalyst. The characterization of the new products involved a combination of methods including elemental analyses, IR, UV–vis, 1H NMR, 13C NMR and mass spectroscopies. Most of the new compounds 3–10 exhibited important antimicrobial activity.