Optical Properties and Structural Rearrangement of Guest NLO Molecules Studied by Different Solvation Models
The presented work focus on quantum chemical calculations of linear and nonlinear optical properties of organic and inorganic molecules located in PMMA matrix. As organic molecules the family of imidazole-derived push-pull structures was taken into account. The SiC nanograins with size of 1.2 nm in cubic and hexagonal structure as inorganic chromophore were also analysed. The electronic properties were calculated for the molecules with geometries optimized in gas-phase as well as affected by polymeric environment. The time dependent functional density theory and time dependent Hartree-Fock formalism were used for the quantum chemical calculations for SiC and imidazoles, respectively. For the SiC/ PMMA composite the hierarchical approach was applied involving the use of molecular dynamics and then quantum chemical calculations methodology. For the organic chromophores the C-PCM model was tested. The solvent effect on the geometry of chromophores is more pronounced for the inorganic nanograins than for organic molecules but in both cases it should be taken into account specially supporting the nonlinear optical properties calculations.
Keywords: nonlinear optics, composite materials, computer simulations