Synthesis, photophysical and photochemical properties of metal-free and zinc(II) phthalocyanines bearing α-naphtholbenzein units

Synthesis of metal-free and zinc (II) phthalocyanine complexes bearing α-naphtholbenzein units was described. Precursor required for the preparation of phthalocyanine complexes was prepared by nucleophilic aromatic substitution reaction between 4-nitrophthalonitrile and α-naphtholbenzein. Cyclotetramerization reactions of the new dinitrile derivative were accomplished in dry dimethylformamide at refluxed temperature. The new compounds were characterized by using elemental analyses, proton and carbon nuclear magnetic resonance, fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, fluorescence spectroscopy and mass spectrometry. The photophysical and photochemical properties of metal-free and zinc (II) phthalocyanines were studied in tetrahydrofuran. The fluorescence of the phthalocyanine complexes was effectively quenched by 1,4-benzoquinone (BQ) in tetrahydrofuran. The effect of the concentration on the aggregation properties and solvent effects on the absorption spectra of phthalocyanine complexes were also investigated.