PMSE 14 |
| Polyaniline in its protonated emaraldine form, is a well-known conducting polymer that finds applications in many microelectronics and sensor devices, just to state these two. Quinone diimines in their protonated and reduced forms have often been used as model compounds in order to extract information on the possible structures of polyaniline, and on the structure-property relationship of this conducting polymer. Organometallic conducting polymers are also known, and among these, many can be prepared using the anchoring ethynyl function. We now wish to report the synthesis, characterization (including X-ray structures) and UV-vis and electrochemical behavior of two series of bis(phenylethynyl)quinone diimine building blocks for organometallic polymers. These deeply colored materials are (Me3Si-C≡C-1,4-C6H4-)2[N=C6H4=N] and (Me3Si-C≡C-1,2-C6H4-)2[N=C6H4=N] where X = F, Cl, Me. Both conformers, cis- and trans-, are observed in some cases. The molecular and electronic structures, UV-vis and electrochemical data were complemented by DFT data. Charge-transfer excited states are predicted from DFT where the donor and acceptor fragments are Me3Si-C≡C-1,4-C6H4- and N=C6H4=N, respectively, and experimental data indeed suggest the presence of pp* state as the lowest energy excited state. In the protonated form, electrochemically reversible waves were observed in the cyclic voltamograms for some cases. The cases where X = H (unsubstituted derivatives) will be discussed as well. In these cases, functionalization of the quinone moities is easier than substituting the ketone fragments during reactions. |
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Electroactive and Photoresponsive Metal-Containing Polymers
8:30 AM-12:20 PM, Sunday, 10 September 2006 San Francisco Marriott -- Salon B1, Oral
Division of Polymeric Materials: Science & Engineering |