Impact of Doping on the Reactivity of Photochromic Polymers Containing Styrylquinoline Fragments: Hartree-Fock and Density Functional Theory Study

The main objective of this chapter is to perform Hartree-Fock (HF) and Density Functional Theory (DFT) calculations to investigated the effect of potassium doping on optoelectronic, electronic, linear and nonlinear optical properties of methacrylate monomers containing styrylquinoline moieties. Conducting polymers are an exciting class of organic electronic materials, which have attracted an increasing interest in the fields of bioelectronics and their biomedical applications. Their unique features such as mixed ionic-electronic conductivity, good biocompatibility, as well as mechanical softness make them favored candidates for an effective conduit between the worlds of electronics and biology. HF and DFT were used in this research work to investigate the impact of doping on the structural, thermodynamic, optoelectronic, electronic and nonlinear optical properties of the reference monomers M1 and M2. Three doped monomers were investigated including, the monomer M3 obtained from M1 by substituting the hydrogen (H) atom with a potassium atom, the monomer M4 by substituting two H atoms and the monomer M5 obtained from M2 by substituting the H atom. Results showed that using potassium and the nitro group to modify virgin styrylquinoline monomers' electrical characteristics is a great method. Thermodynamic findings of doped monomers revealed thermodynamically stable materials with significant reactivity that is suitable for reactions with other compounds. In fact, potassium doping decreases the enthalpy of doped monomers and promotes their thermodynamic stability. In fact, the energy gap decreases from 3.82 eV for M1 to 3.02 eV and to 2.92 eV for M3 and M4, respectively; while the decrease from 3.43 eV for M2 to 2.52 eV for M5 was observed, thus demonstrating the good semiconductor character of the obtained compounds with relevant applications in the manufacture of solar cells. In addition, potassium doping is an appropriate method to enhance optoelectronic properties of styrylquinoline virgin monomers. Thus, the refractive index of doped monomers is greater than that of glass, which is a reference in optic and can be used under high electric fields of the order of 1.90´109 Vm-1 for monomer M4 up to 7.01´109 Vm-1 for M3 and to 10.89´109 Vm-1 for M5. Finally, the strong enhancement of linear and nonlinear optical (NLO) properties observed leads to the conclusion that these doped monomers may be suitable candidates in devices requiring good NLO properties.