ORGN 661 |
| A novel π-conjugated dendritic nano-sized chromophore, 1,3,5-tris-(7,12-bis-(2-{4-[2-(7-diphenylamino-9,9-dibutyl-9H-fluoren-2-yl)-vinyl]-phenyl}-vinyl)-5,5,10,10,15,15-hexabutyl-10,15-dihydro-5H-diindeno[1,2-a;1',2'-c]fluoren-2-yl)-benzene, was synthesized and characterized, together with its corresponding one- and three-branched units. The TPA peak value for the dendritic chromophore is 5.47 × 10-20cm4GW-1, 15.6 times larger than that for the one-branched dipolar chromophore. Using comparable structure unit based concentrations, enhanced two-photon excited (TPE) fluorescence was found for the dendritic chromophore. The three-photon absorption (3PA) cross-section peak value for the dendritic compound is 30.0 × 10-25cm6GW-2, 10 times larger than that for the one-branched compound. Considering the structure unit differences in these two chromophores, one may still find a 67 % enhanced 3PA cross-section value in going from the one-branched chromophore to the dendritic chromophore. Owing to its increased three-photon absorption, improved 3PA based optical limiting behaviors were found for the dendritic chromophore compared with the one-branched chromophore using comparable structure unit based concentrations. |
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Materials, Devices, and Switches
1:00 PM-5:00 PM, Thursday, 30 March 2006 Georgia World Congress Center -- Georgia Ballroom 2, Oral
Division of Organic Chemistry |