Experimental and quantum chemical studies of the structural and spectral properties of novel diazenyl formazans

A new series of 3-(p-substitutedphenyl)-5-phenyl-1-(4 phenyldiazenyl)phenylformazans were synthesized by coupling p-substituted phenyl or pyridinylhydrazones with p-aminoazobenzene diazonium chloride. All compounds were characterized by FT-IR, UV-Vis, H-1 NMR, and C-13 NMR spectroscopic techniques, and HR-MS. DFT was used to calculate the molecular structures and H-1 and C-13 chemical shift values of the synthesized compounds with PBE1 PBE functional and 6-311G(2d,2p) basis set combination. The IR spectra of the novel formazans were calculated using DFT at PBE1PBE/6-311G(d,p) level of theory. The electronic absorption spectra of the optimized structures were evaluated by TD-DFT method at PBE1PBE/6-311G(2d,2p) level of theory. The absorption spectra of the synthesized diazenyl formazans were investigated in three different solvents. A good correlation was established between the experimental data and calculated results. (C) 2019 Elsevier B.V. All rights reserved.