Synthesis, characterization and spectral properties of novel zinc phthalocyanines derived from C2 symmetric diol

•Phthalonitrile and bisphthalonitrile derived from optically active C2-symmetric diol were synthesized.•Monomeric and polymeric zinc(II) phthalocyanines bearing optically active C2-symmetric diol at peripheral positions.•Non-aggregated behavior in various organic solvents for monomeric zinc(II) phthalocyanine.

In this study, we described the syntheses of new zinc(II) phthalocyanine compounds derived from (1R,2R)-1,2-diphenyl-1,2-ethanediol units. The phthalonitrile precursors 3 and 4 were synthesized by the reaction of 4,5-dichlorophthalonitrile with (1R,2R)-1,2-diphenyl-1,2-ethanediol. The synthesis of zinc(II) phthalocyanine 5 and zinc(II) phthalocyanine polymer 6 by cyclotetramerization of corresponding phthalonitrile derivative were accomplished in the presence of Zn(CH3CO2)2 in a Schlenk tube containing quinoline under nitrogen atmosphere. The zinc(II) phthalocyanine 5 showed enhanced solubility in various organic solvents. The aggregation behavior of phthalocyanines was investigated at different concentrations in different solvents. Both phthalocyanines were found to exist in non-aggregated form at concentrations between 10 × 10−6 and 1 × 10−6 mol dm−3. As the concentration increased to 5 × 10−5 mol dm−3, a deviation from ideality was observed for both phthalocyanines. The novel compounds were characterized by a combination of elemental analysis and 1H NMR, 13C NMR, IR, UV–Vis and MS spectral data.

Graphical abstractThe present paper reports the synthesis and characterization of two new optically active phthalonitriles 3 and 4, and their zinc phthalocyanine derivatives 5 and 6, respectively. In addition to that, the spectral studies of these phthalocyanines in different solvent were investigated.Figure optionsDownload full-size imageDownload as PowerPoint slide