Work

Exciton Coupling Model for the Emergence of Second Harmonic Generation from Assemblies of Centrosymmetric Molecules

Year: 2014

Type: article

Abstract: A simple model is presented for interpreting the presence of substantial second harmonic generation (SHG) activity from assemblies of centrosymmetric molecular building blocks. Using butadiene as a computationally tractable centrosymmetric model system, time-dependent Hartree-Fock calculations of the nonlinear polarizability of butadiene dimer were well-described through exciton coupling arguments based on the electronic structure of the monomer and the relative orientation between the monomers within the dimer. Experimental studies of the centrosymmetric molecule 2,6-di-tert-butylanthraquinone suggest the formation of a combination of SHG-active and SHG-inactive crystal forms. The structure for the centrosymmetric form is known, serving as a negative control for the model, while the presence of an additional SHG-active metastable form is consistent with predictions of the model for alternative molecular packing configurations.

Source: The Journal of Physical Chemistry A

DOI: 10.1021/jp5003935

Authors: Gregory R. Snyder, Azhad U. Chowdhury, Garth J. Simpson

Institution: Purdue University West Lafayette

Language: English

Topic: Nonlinear Optical Materials Research

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Funders: Weizmann Institute of Science, National Institutes of Health, NIH Office of the Director, National Institute of General Medical Sciences