Exploring nonlinear optical properties in a hybrid dihydrogen phosphate system: an experimental and theoretical approach.

CONTEXT: The controlled slow evaporation process conducted at room temperature has produced a novel hybrid material denoted as (2-hydroxyethyl) trimethylammonium dihydrogen phosphate [2-HDETDHP] (C5 H14 NO+ , H2 PO4 - ), synthesized through the solution growth method. X-ray crystallography analysis reveals a triclinic structure with a filling rate of P and a Z value of 2. This hybrid material displays noteworthy absorption characteristics in the middle and far ultraviolet regions. UV-visible spectroscopy further establishes its transparency in the visible and near-visible ultraviolet domains. FT-IR spectroscopy examines various vibration modes, elucidating their relationships with the functional groups within the structure. Two- and three-dimensional fingerprint maps, coupled with three-dimensional crystal structures through Hirshfeld Surface Analysis, unveil the dominance of O•••H and H•••H interactions in the structure, comprising 49.40% and 50.40%, respectively. Fingerprint plots derived from the Hirshfeld surface assess the percentages of hydrogen bonding interactions, with 80.6% attributed to a fragment patch. The experiment of antimicrobial efficacy of a synthesized product, conducted in triplicate, demonstrated the synthesized product's potential antimicrobial activity.

METHODS: Hirshfeld surfaces are employed to investigate intermolecular hydrogen bonding, specifically within single phosphate groups. The molecular structure of 2-HDETDHP was refined using single-crystal X-ray analysis, while its optical characteristics were examined through UV-visible spectroscopy. FT-IR spectroscopy is employed for the assignment of molecular vibrations of functional groups in the affined structure. Quantum calculations were executed with the GAUSSIAN 09 software package at B3LYP/6-311G level of theory, to optimize the molecular geometries. The antimicrobial efficacy of a synthesized product was evaluated using the disc diffusion method against antibiotic-resistant Candida albicans, Candida tropicalis, Aspergillus niger, Staphylococcus aureus, and Escherichia coli. Microorganisms were cultured on nutrient agar, and inhibition zones were measured after incubation, with streptomycin and amphotericin as positive controls.