Theoretical Study of 1,4-Dioxane in Aqueous Solution and Its Experimental Interaction with Nano-CuSO4

The electronic structure, Non-Linear Optical (NLO) properties and Natural Bonding Orbital (NBO) analysis of 1,4-dioxane were investigated using the theoretical study of Density Functional Theory (DFT) calculations at the B3LYP/6-311G (d,p) level of theory. The optimized structure is nonlinear as indicated from the dihedral angles.  Natural bonding orbital analysis has been analyzed in terms of the hybridization of each atom, natural charges (Core, Valence and Rydberg), bonding and antibonding orbital's second order perturbation energy (E(2)</sup>). The calculated EHOMO</sub> and ELUMO</sub> energies of the title molecule can be used to explain the charge transfer in the molecule and to calculate the global properties; the chemical hardness (η), softness (S) and electronegativity (χ). The NLO parameters: static dipole moment (µ), polarizability (α), anisotropy polarizability (Δα) and first order hyperpolarizability (βtot</sub>) of the studied molecule have been calculated at the same level of theory. The Molecular Electrostatic Potential (MEP) and  Electro Static Potential (ESP) for 1,4-dioxane were investigated and analyzed.  Also, the electronic absorption spectra were discussed by Time-Dependent Density Functional Theory (TD-DFT) calculations for 1,4-dioxane in 10% ethanol/water. From the experimental conductance measurements, the association thermodynamic parameters (KA, </sub>∆GA</sub>, ∆HA</sub> and ∆SA</sub>) and complex formation thermodynamic parameters (Kf, </sub>∆Gf</sub>, ∆Hf</sub> and ∆Sf</sub>) of nano-CuSO4</sub> in the presence of 1,4-dioxane as a ligand in 10% ethanol-water at different temperatures (298.15, 303.15, 308.15 and 313.15 o</sup>K) were applied and calculated.