Organometallic hexa-aqua magnesium hydrogen maleate third-order nonlinear optical crystal for NLO and optoelectronic device applications

Hexa-aqua magnesium hydrogen maleate single crystal was generated by slow evaporation method. By using single-crystal X-ray diffraction, the crystal structure of hexa-aqua magnesium hydrogen maleate has been identified. It is a member of the monoclinic system with space group P21/c and the lattice parameter as A = 10.207(5) Å, B = 11.829(5) Å, C = 6.745(3) Å, and volume V = 789.499 ų. FTIR spectroscopy was used to analyze the crystal’s functional groups. Thermogravimetric and differential thermal analyses have been used to examine the thermal stability and melting point of the hexa-aqua magnesium hydrogen maleate single crystal. UV–vis transmittance spectrum was identified in the range of 200–1100 nm. The band gap of an HMHM single crystal (E_g) has been calculated using extrapolation of the linear component with 4.9 eV. Vickers microhardness experiments were used to examine the crystal’s mechanical stability. The grown material belongs to soft category with ‘n’ value of 2.7. The hyperconjugative interaction was explained using the natural bond orbital (NBO) approach. The HOMO–LUMO plot was used to determine the molecule’s chemical potential, electronegativity, and chemical hardness.