Hydrogen bonding interaction and topological insights of the electron localization/delocalization of l- arginine acetate

The vibrational spectral studies of the semi-organic material l- arginine acetate (LAA) are carried out with the help of density functional calculations to derive the equilibrium geometry as well as the vibrational wavenumbers and intensities of the spectral bands. The vibrational spectrum assignments are performed using normal coordinate analysis (NCA) in accordance with the scaled quantum mechanical force field approach (SQMFF). Vibrational spectra confirm the COO- modes split due to intra- and intermolecular association based on C–O….H, N–H….O, and O–H⋯O hydrogen bonding in the molecule, which lowers carboxylate wavenumbers. The natural bond orbital (NBO) analysis and DFT computations also confirm the occurrence of strong intra and intermolecular N–H⋯O and O–H⋯O ionic hydrogen bonding between charged species, providing the non-centrosymmetric structure in the LAA crystal. The content differences of Zn, Y, Na and Al in the alteration layer of glass were investigated by EDS line scanning. Zn and Y elements are enriched in the alteration layer. [Display omitted] •Structural and vibrational investigation of LAA are carried out.•Topological approach helps in understanding the nature of hydrogen bonding.•The effect of molecular association through hydrogen bonding was discussed.