Second-order nonlinear optical responses of flexible pyridine-pyrimidine foldamers

Using a theoretical approach combining classical molecular dynamics and quantum chemistry calculations, we investigate the impact of the dynamical disorder, as well as of the impact of chemical substitution, on the nonlinear optical responses of helical oligomers based on pyridine-pyrimidine units. The fluctuations in the Hyper-Rayleigh scattering and electric field-induced second harmonic generation responses are analyzed with respect to the geometrical changes along molecular dynamics conducted at room temperature, providing therefore an insight into the relationships between the nature of the unit cell, the thermally induced geometrical fluctuations of the system, and its NLO properties.