Experimental and In Silico studies on optical properties of new thiadiazole tetrasubstituted metal-free and zinc phthalocyanine compounds

In this study, 2-amino-5-phenyl-1,3,4-thiadiazole substituted metal-free phthalocyanine (H2Pc) was synthesized by tetramerization reaction of the phthalonitrile derivative. The synthesized compound was characterized by IR, UV–Vis, 1H NMR, MS spectroscopy and elemental analysis. To determine the potential of the synthesized phthalocyanines to be used in optical applications (thiadiazole substituted metal-free and zinc(II) derivatives), photoluminescence and fluorescence properties of compounds were studied. In addition, the powder and thin film surface morphology of these compounds were examined by scanning electron microscope (SEM). The electronic features (chemical hardness, electron affinity, electronegativity) and frontier orbital energy levels (HOMO-LUMO) were computed using density functional theory. The HOMO-LUMO energies of (H2Pc) and zinc(II) phthalocyanine (ZnPc) were acquired close to each other. The spectroscopic studies showed that the UV–visible spectra obtained using time-dependent density functional theory (TDDFT) was compatible with the experimental UV–visible study. The nonlinear optical (NLO) results indicated that the NLO properties of H2Pc are slightly better than ZnPc.