The Mechanism, Kinetic Study and Non-Linear Optical Properties (NLO) of Para-Chloroaniline Using DFT Approach

Abstract

The synthesis of poly-p-chloroaniline (PpCA) by oxidative chemical polymerization using potassium dichromate as oxidizing agent was carried out. The optimum conditions for the polymerization reaction and the order of reactions and thermodynamic activation parameters were investigated. A molecular mechanism for the oxidation of p-chloroaniline using potassium dichromate is proposed. The TGA analysis and spectroscopic studies IR, UV-vis and elemental analysis have evidenced the structure of polymeric chain. The surface morphology of the obtained polymer was characterized by X-ray diffraction and transmission electron microscopy (TEM). Moreover, determinations of dielectric properties of the prepared polymer were carried out. The a.c conductivity (σac) of (PpCA) was investigated as a function of frequency and temperature. The microscopic conduction mechanism of charge carries over the potential barrier in polymer backbone was found classical hopping model. The electronic structure of neutral PpCA, radical cation and dimer radical cation are investigated theoretically at the B3LYP/6-311G** level of theory. The mechanism of the polymerization process is discussed and analyzed. The calculated EHOMO and ELUMO energies of the studied compounds can be used to calculate the global properties; chemical hardness (η), softness (S) and electronegativity (χ). The calculated nonlinear optical parameters (NLO); polarizibilty (α), anisotropy of the polarizibility (Δα) and first order hyperpolarizibility (β) of the studied compounds show promising optical properties. 3D-plots of the molecular electrostatic potential (MEP) for neutral monomer and radical cation dimer are investigated and analyzed showing the distribution of electronic density of orbitals describing the electrophilic and nucleophilic sites of the neutral monomer and radical cation dimer.