ORGN 599 |
| We present here the synthesis and structural characterization of a series of new chrompohores with emphasis on fluorene as a pi-bridge. Using this synthetic versatility, fluorene derivatives with systematically altered structural motifs were prepared and different electron-acceptor (A) and/or electron-donating (D) groups, with some separated by linking (L) groups, were incorporated into the design architecture. The systematic alteration of these molecules gave rise to a numerous of factors which affected the nonlinearity, and effects of structural symmetry, solvent polarity, strengths of electron donating and/or withdrawing end-groups, and pi-conjugation extensions were thoroughly analyzed. The comprehensive spectroscopic study of these fluorene derivatives comprised absorption, fluorescence emission, excitation, quantum yield, and nonlinear properties two-photon absorption (2PA) cross-sections. 2PA cross sections were determined by two independent methods; a nonlinear transmission method employing a white light continuum (WLC) spectroscopy and a two-photon fluorescence (2PF) spectroscopy. In addition, excitation anisotropy studies allowed the determination of the spectral position of the various electronic transitions. Analysis of the experimental data provided substantial information on understanding some molecular structure/linear and two-photon property relationships for this series of chromophores studied. |
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Heterocycles, Aromatics, Metal-Mediated Reactions and Syntheses, Materials, Devices, and Switches
8:00 PM-10:00 PM, Wednesday, 29 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster
Division of Organic Chemistry |