Vibrational spectroscopic studies and DFT computation of the nonlinear optical molecule L-Valinium formate

•Optimized geometry reveals the existence of optical nonlinearity and NH⋯O hydrogen bonding in the molecule.•Calculated first order hyperpolarizability indicates that LVF crystal is a potential candidate for NLO applications.•Strong intramolecular NH⋯O hydrogen bonding interactions enhances molecular stability.•Lowering of HOMO–LUMO energy gap suggests the possibility of intramolecular charge transfer in the molecule.•Lowering of carbonyl and red shift in NH3+ stretching band in IR and Raman shows clear evidence of inter and intra molecular interaction.

The Fourier Transform Infrared and Raman spectra of the L-Valinium formate have been recorded and analyzed. The assignments of the bands of the vibrational spectra have been carried out with the aid of Normal Coordinate Analysis following the calculated quantum mechanical force field methodology. Optimized geometry of the molecule has computed using of Density Functional Theory method. Natural Bond Orbital Analysis, Mulliken’s net charges and the atomic natural charges are also predicted. HOMO and LUMO energy gap value suggest the possibility of charge transfer within the molecule. The thermodynamic properties at different temperatures are also calculated.

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