Design, Synthesis, and Structural and Spectroscopic Studies of Push-Pull Two-Photon Absorbing Chromophores with Acceptor Groups of Varying Strength
Abbreviated Journal Title
J. Org. Chem.
NONLINEAR-OPTICAL CHROMOPHORES; FLUORENYL-BASED CHROMOPHORES; ORGANIC; MATERIALS; CROSS-SECTIONS; ABSORPTION; DERIVATIVES; DENSITY; EXCITATION; MOLECULES; DIPOLAR; Chemistry, Organic
A new series of unsymmetrical diphenylaminofluorene-based chromophores with various strong g-electron acceptors were synthesized and fully characterized. The systematic alteration of the structural design facilitated the investigation of effects such as molecular symmetry and strength of electron-donating and/or -withdrawing termini have on optical nonlinearity. In order to determine the electronic and geometrical properties of the novel compounds, a thorough investigation was carried out by a combination of linear and nonlinear spectroscopic techniques, single-crystal X-ray diffraction, and quantum chemical calculations. Finally, on the basis of two-photon absorption (2PA) cross sections, the general trend for pi-electron accepting ability, i.e., ability to accept charge transfer from diphenylamine was: 2-pyran-4-ylidene malononitrile (pyranone) > dicyanovinyl > bis(dicyanomethylidene)indane >1-(thiophen-2-yl)propenone > dicyanoethylenyl >3-(thiophen-2-yl)propenone. An analogue with the 2-pyran-4-ylidene malononitrile acceptor group exhibited a nearly 3-fold enhancement of the 2PA cross section (1650 GM at 840 nm), relative to other members of the series.
Journal of Organic Chemistry
"Design, Synthesis, and Structural and Spectroscopic Studies of Push-Pull Two-Photon Absorbing Chromophores with Acceptor Groups of Varying Strength" (2013). Faculty Bibliography 2010s. 4426.