Experimental and computational investigations on the molecular structure, vibrational spectra, electronic properties, and molecular electrostatic potential analysis of phenylenediamine isomers

The experimental Fourier Transform-Infrared, Raman, and Ultraviolet-Visible spectral data along with the theoretical quantum chemical calculations for phenylenediamine isomers were investigated in detail. Vibrational modes were assigned by potential energy distributions. Energy gap, ionization potential, electron affinity, and electronegativity descriptors were obtained from frontier molecular orbitals. Molecular electrostatic potential surfaces were plotted to estimate chemical reactivity at isomers. It was aimed to determine the isomeric effect on the characterization of molecules by theoretical and experimental analysis. By using DFT/B3LYP method with aug-cc-PVDZ basis set, the structural and spectral properties of the molecule studied were interpreted.