Theoretical calculations of solvation 12-Crown-4 (12CN4) in aqueous solution and its experimental interaction with nano CuSO4

Abstract

Theoretical study of the electronic structure, and nonlinear optical properties (NLO) analysis of 12-crown-4were done using Density Functional Theory (DFT) evaluations at the B3LYP/6-311G (d,p) level of theory. The optimized structure is nonlinear compound as indicated from the dihedral angles were presented. The calculated E_HOMO and E_LUMO energies of 12-Crown-4 (12CN4) can be used to explain the charge transfer in 12-Crown-4 (12CN4) and to calculated the global properties; the chemical hardness (<em>η</em>), softness (<em>S</em>) and electronegativity (χ). The NLO parameters: static dipole moment (<em>µ</em>), polarizability (<em>α</em>), anisotropy polarizability (<em>Δα</em>) and first order hyperpolarizability (<em>β_tot</em>) of the 12-Crown-4 (12CN4) have been calculated at the same level of theory.The molecular electrostatic potential (MEP) and electrostatic potential (ESP) for the title molecule were investigated and analyzed. Also the electronic absorption spectra were measured in ethanol and water solvents and the assignment of the observed bands has been discussed by time-dependent density functional theory (TD-DFT) calculations. The correspondences between calculated and experimental transitions energies are satisfactory. From the experimental conductance measurements, the association thermodynamic parameters (K_A,∆G_A, ∆H_A and ∆S_A) and complex formation thermodynamic parameters (K_f,∆G_f, ∆H_f and ∆S_f) for nano-CuSO₄ in presence of 12-crown-4 (12CN4) as chelating agent in 10% ethanol – water solvents at different temperatures (298.15, 303.15, 308.15 and 313.15K) were applied and calculated.