Molecular modeling and nonlinear optical properties of new isostructural halogenated dihydroquinolinones.

Two new isostructural halogenated dihydroquinolinones were synthesized and characterized by single crystal X-ray diffraction. A detailed isostructural analysis of the electronic and optical properties is presented using density functional theory models with emphasis on the structure–property relationship in the solid phase. The physicochemical properties such as molecular electrostatic potential, frontier molecular orbitals as well as the nature of intermolecular interactions and the interaction energy of dimeric structures are almost unaffected by the replacement of the bromine atom by the chlorine atom. Starting from the embedded unit cells, the third-order nonlinear susceptibility (χ⁽³⁾) of the newly synthesized crystals has been estimated using an iterative electrostatic scheme, in which the surrounding molecules are represented by point charges. Theoretical results illustrate the role played by the environment polarization effect and halogenated substituents on χ⁽³⁾ which has the same order of magnitude as those observed in other organic crystals. Our findings suggest that the dihydroquinolinone derivative crystals are very promising NLO materials. [ABSTRACT FROM AUTHOR]