First theoretical probe for alkynyl bridged thiophene modified coumarin nonlinear optical materials with D-pi-A and A-pi-D-pi-A structures

First-principles exploration is very important to molecular design. In this study, geometric structure, intramolecular charge transfer (ICT), energy levels, polar moment, and ultraviolet-visible (UV-Vis) spectroscopy of eight novel and different alkynyl bridged thiophene modified coumarin nonlinear optical molecules with D-pi-A and A-pi-D-pi-A structures had been studied by density-functional theory (DFT) calculations within B3LYP hybrid functional using 6-31 G(d, p) Gaussian type molecular-orbital basis set. This has guiding significance for the design of nonlinear optical molecules and the development of coumarin-based photoelectric molecules.