Synthesis, supramolecular structure, spectral properties and correlation between nonlinear optic, thermochemistry and thermal behavior of an α-Hydroxyphosphonate acid ester, dual experimental and DFT approaches

Abstract First, we note in this paper that α-Hydroxyphosphonate acid ester was synthesized before; we confirmed it by a new method and its various properties are discussed experimentally and theoretically. The structure of Diethyl [hydroxy(4-methoxyphenyl) methyl] phosphonate (DH4MPMP) resolved by SXRD is compared to the optimized geometry, the FT-IR, NMR, UV-Vis spectroscopies results were compared and discussed experimentally and theoretically. The Hirshfeld surface analyses were employed to determine qualitative and quantitative intermolecular interactions present in the solid state and through, the supramolecular 3D-network was discussed. The UV-Vis spectrum exhibit a strong absorption in middle UV domain and an optical transmittance in the visible one. To be close from the experimental results, all DFT calculations based on B3LYP/6-31G (d,p) were detailed on monomer and dimer models. The DFT calculation of the second-order nonlinear optical properties is based on the first static hyperpolarizability (β), the results show that the material might have nonlinear optical properties. The calculated frontier molecular orbitals and their energies were calculated. The research was extended to the calculations of the molecular electrostatic potential map; it shows negative potential areas localized around oxygen atoms as well as the positive localized around the hydrogen atoms. Finally, the thermodynamic functions (entropy, heat capacity and enthalpy) were determined from spectroscopic data by statistical methods in the range 100–1000 K and the experimental thermal decomposition behavior was analyzed by TGA.