Theoretical study on the third-order nonlinear optical properties and structural characterization of 3-Acetyl-6-Bromocoumarin

Coumarin derivatives exist widely in nature and show a wide range of biological activities such as anti-inflammatory, anti-oxidative and anti-cancer. The structure of C11H7BrO3 has been redetermined using 3330 measured reflections with 1666 unique [Rint = 0.0088] with final indices R1 = 0.0128 [I > 2 sigma(I)] and wR(2) = 0.0347 (all data). The bromocoumarin molecule is almost planar and has three planar dimers stabilized by interaction of type C-H center dot center dot center dot Br and CAH center dot center dot center dot O, which form parallel layers connected via several pi-p interactions [centroid-centroid distances = 3.958(1) angstrom]. To provide a view of the non-linear optical behavior of third order of the crystal bromocoumarin in both cases static and dynamic, we calculate the linear polarizability (alpha) and the second hyperpolarizability (gamma) using a new supermolecule approach combined with an iterative electrostatic scheme where the neighboring molecules are represented by point charges. The results of calculations of the HOMO and LUMO energies show the occurrence of charge transfer inside the molecule. The computational results of the second (static and dynamics) hyperpolarizabilities show the molecule exhibiting second hyperpolarizability with values different of zero, which implies a third order microscopic behavior. (C) 2016 Elsevier B.V. All rights reserved.