Structural, spectroscopic, physical properties and quantum chemical investigation on bromide salt of 4-dimethylaminopyridine NLO material for optoelectronic applications
In this paper, investigations on the crystal structure, vibrational, physical properties on charge transfer single crystals of 4-dimethylaminopyridinium bromide. Its structural parameters, vibrational, mechanical and optical properties have been studied by SCXRD, FT-IR, FT-Raman, Vickers microhardness test and Ultraviolet-Visible spectral analysis. The computational investigations were carried out to determine the molecular geometries, vibrational modes, HOMO-LUMO analysis, population analysis, MEP, thermodynamics and macroscopic NLO response of the compound. The theoretical and experimental molecular geometrical parameters and vibrational assignments have been in good agreement. Mulliken charge distribution of the present compound was studied systematically. The chemical hardness, electro-negativity and chemical potential of the molecule have been computed by HOMO - LUMO plot. FMO analysis indicates the electron delocalization on the title compound and also its low value of energy gap indicates electron transfer. NLO parameters were calculated by HF and DFT methods. The calculated hyperpolarizability values showed that the compound is a good candidate for NLO applications.