Synthesis of novel highly efficient two-photon chromophores using fluorenyl bridge bearing electron donor or acceptor groups

ORGN 598

Sheng Yao, syao@mail.ucf.edu1, Kevin D. Belfield, belfield@mail.ucf.edu2, Florencio E. Hernandez3, Ion Cohanoschi3, and Joel M Hales, Joel.Hales@chemistry.gatech.edu4. (1) Department of Chemistry, University of Central Florida, 4000 Central Florida Boulevard, P.O. Box 162366, Orlando, FL 32816-2366, (2) Department of Chemistry and CREOL, College of Optics and Photonics, University of Central Florida, 4000 Central Florida Blvd., P.O. Box 162366, Orlando, FL 32816-2366, (3) Department of Chemistry and College of Optics and Photonics: CREOL and FPCE, University of Central Florida, P.O. Box 162366, Orlando, FL 32816-2366, (4) School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics, Georgia Institute of Technology, 770 State Street NW, Atlanta, GA 30332-0400
Two-photon absorbing chromophores bearing electron-donating amino or electron-withdrawing nitro groups or branches at central fluorenyl bridge were synthesized. An synthetic method was developed via novel [4,7-Bis-(diethoxy-phosphorylmethyl)-9,9-diethyl-9H-fluoren-2-ylmethyl]-phosphonic acid diethyl ester and 9,9-bis-decyl-4,5-dinitro-9H-fluorene-2,7-dicarbaldehyde intermediates. The dyes were prepared by Horner-Emmons coupling of correspondent aldehyde and phosphonic acid diethyl ester with relatively high yields. Reduction of the central nitro groups in 4 to amino groups in 5 alternated the electron acceptors to donors. The central donors or acceptors can facilitate the intramolecular charge transfer during the nonlinear absorption process, hence, increase the 2PA cross-sections. The linear optical properties of the compounds were investigated by UV-visible, steady-state fluorescence, and excitation anisotropy spectroscopic measurements. Very high two-photon absorption (2PA) cross-sections (>80,000 GM) were achieved as determined by open aperture Z-scan technique using picosecond laser excitation sources.

 

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

The 231st ACS National Meeting, Atlanta, GA, March 26-30, 2006