Modeling of Nonlinear Optical Activity of Epoxyamine Oligomers with Binary Chromophore Groups

• Published in: Macromolecular theory and simulations Vol. 25; no. 6; pp. 591 - 600
• Main Authors: Levitskaya, Alina I., Fominykh, Olga D., Balakina, Marina Yu
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01-11-2016; Wiley Subscription Services, Inc
• Subjects: Chromophores; Composite materials; dipole chromophores; Dynamical systems; ESP charges; Fragments; Materials selection; Modelling; Molecular dynamics; Molecular structure; Nonlinear dynamics; nonlinear optical characteristics; Nonlinear optics; Nonlinearity; Oligomers; Optical activity; Optical properties; Polymer matrix composites; Quantum chemistry; simulations; Tethering
• ISSN: 1022-1344; 1521-3919
• DOI: 10.1002/mats.201600054

The molecular systems, modeling composite materials, are formed by the epoxy‐amine oligomers with covalently bound chromophore‐containing dendritic fragments (EAD) as a host and additional azo‐chromophores as guests. The relationship between the structure and quadratic nonlinear optical characteristics of the model systems is established by atomistic modeling and quantum chemistry. The effect of the chain length of the model systems and the choice of the dendron structure, in particular, the length of the groups tethering chromophores to the branching center, on the values of first hyperpolarizability is studied. Molecular dynamics, performed for the model systems at various temperatures, reveals chromophores local mobility at temperature close to 130 °C; the calculations being fulfilled with the force field MMFF94s modified in terms of the ESP partial charges estimate at B3LYP/6‐31G(d) level.
Atomistic modeling of composite systems on the basis of epoxy‐amine oligomers with covalently bound chromophore‐containing dendritic fragments as a host‐matrix and additional azo‐chromophores as guests is performed. Nonlinear optical characteristics of the studied systems are calculated by DFT. The incorporation of guests results in self‐organization of chromophores, the optimal ratio being defined as one guest per dendron.