Computational and spectral studies of 6-phenylazo-3-(p-tolyl)-2H-chromen-2-one

•6-Phenylazo-3-(p-tolyl)-2H-chromen-2-one was synthesized and characterized.•Vibrational assignments done by means of potential energy distribution (PED%) calculation using VEDA program.•AIM theory supports the presence of intramolecular hydrogen bond.•NBO analysis confirmed intramolecular charge transfer.•NLO behaviour is 92 times that of urea.

6-Phenylazo-3-(p-tolyl)-2H-chromen-2-one 4 was prepared and characterized by IR, 1H, and 13C NMR spectral studies. The optimized structure of the chromen-2-one 4 was investigated by the Gaussian 03 B3LYP density functional method calculations at 6-31G(d,p) basis set. The gauge-independent atomic orbital (GIAO) 13C and 1H chemical shift calculations for the synthesized chromen-2-one in CDCl3 were also made by the same method. The computed IR frequencies of the chromen-2-one and the corresponding vibrational assignments were analyzed by means of potential energy distribution (PED%) calculation using vibrational energy distribution analysis (VEDA) program. The first order hyperpolarizability (βtot), polarizability (α) and dipole moment (μ) were calculated using 6-311G(d,p) basis set and the nonlinear optical (NLO) properties are also addressed theoretically. Stability of the chromen-2-one 4 molecule has been analyzed by calculating the intramolecular charge transfer using natural bond order (NBO) analysis. The molecular electrostatic potentials, HOMO–LUMO energy gap and geometrical parameters were also computed. Topological properties of the electronic charge density in chromen-2-one 4 were analyzed employing the Bader’s Atoms in Molecule (AIM) theory which indicated the presence of intramolecular hydrogen bond in the molecule.

Graphical abstractSpectral and DFT studies were made for the synthesized 6-phenylazo-3-(p-tolyl)-2H-chromen-2-one.Figure optionsDownload full-size imageDownload as PowerPoint slide