{"92351":{"#nid":"92351","#data":{"type":"event","title":"(09-0202) Dr. Lothar Dunsch, Leibniz","body":[{"value":"\u003Cp\u003E Dr. Lothar Dunsch, Leibniz-Institute for Solid State and Materials Research (Dresden, Germany)\n\u003C\/p\u003E\n\u003Cp\u003ECharged States in Conducting Polymers as studied by in situ ESR UV\/Vis NIR Spectroelectrochemistry\n\u003C\/p\u003E\n\u003Cp\u003ECOPE Seminar Series\n\u003C\/p\u003E\n\u003Cp\u003EA review is given on recent studies of charged states in conducting polymers using ESR\/UV\/Vis NIR spectroelectrochemistry. It is demonstrated that this method is a prerequisite to study the charged states formed at oligomers and polymers [1],[2]. This in situ ESR\/UV\/Vis NIR spectroelectrochemical method is applied to aniline and its reactions of dimers and other oligomers. [3], to \u0026#945;,\u0026#945;\u00b4-bis(diphenylamino)-capped oligothiophenes [4] and to the reactivity of thiophene oligomers with changing substitution pattern [5]. The chain length dependence of dimerisation reactions and the stabilisa\u00action of charged states are studied for fluorantheno-pyracylenes where the equilibrium of their \u0026#963;-dimers in solution  and the stabilisation of the radical ions for longer oligomers are followed [6].  The growing of the chain length makes any dimerisation negligible in the temperature range under study.\n\u003C\/p\u003E\n\u003Cp\u003EFurthermore, by the extension of oligomeric structures conducting polymers in their spectroelectrochemical behaviour are one of the main subjects as a detailed analysis of both the ESR and the absorption spectra makes a differentiation of the charged states in polymers available [7]. Like for the analysis of polyaniline [8] it is demonstrated for polypyrrole how the formation and equilibria of both polarons and bipolarons can be described experimentally [9]. For polythiophene it is shown that the copolymerisation of different 3-substituted monomers changes the charged state of the copolymer markedly by stabilizing other species [10]. Thus a change from bipolarons to polaron pairs can be followed which is preferably detected by the described in situ triple spectroelectrochemical technique as demonstrated for polyazulene [11]. Furthermore this spectroelectrochemical technique opens the way to study of interactions of paramagnetic metal ions with spin states at organic ligands. This is demonstrated for polysalenes [12]. An outlook is given on future developments of the method.\n\u003C\/p\u003E\n\u003Cp\u003ELiterature:\n\u003C\/p\u003E\n\u003Cp\u003E[1] L. Dunsch, A. Petr, Ber. Bunsenges. Phys. Chem. 1993,  97, 436; A. Petr, L. Dunsch , A. Neudeck, J. Electroanal. Chem. 1996, 412, 153\u003Cbr \/\u003E\n[2] P. Rapta and L. Dunsch, J. Electroanal. Chem. 2001, 506, 22\u003Cbr \/\u003E\n[3] A. Petr und L. Dunsch, J. Electroanal. Chem. 1996, 419, 55\u003Cbr \/\u003E\n[4] D. Rohde, L. Dunsch,  A. Tabet, H. Hartmann, J. Fabian, J. Phys. Chem. B 2006, 110, 8223\u003Cbr \/\u003E\n[5] P. Rapta, O. Zeika, D. Rohde, H. Hartmann, L. Dunsch, ChemPhysChem 2006 7, 863; P. Rapta, D. Rohde, H. Hartmann, L. Dunsch, Tetrahedron Lett. 2006, 47, 7587\u003Cbr \/\u003E\n[6] L. Dunsch, P. Rapta, N. Schulte, A. D. Schl\u00fcter, Angew. Chem. 2002, 114, 2187\u003Cbr \/\u003E\n[7] A. Neudeck, A. Petr, und L. Dunsch, J. Phys. Chem. B 1999, 103, 912\u003Cbr \/\u003E\n[8] A. Neudeck, A. Petr, L. Dunsch, Synth. Met. 1999, 107, 143\u003Cbr \/\u003E\n[9] P. Rapta, A. Neudeck, A. Petr und L. Dunsch, J. Chem. Soc., Faraday Trans. 1998,  94, 3625\u003Cbr \/\u003E\n[10] J. Tar\u00e1bek, P. Rapta, E. J\u00e4hne, D. Ferse, H.-J. Adler, M. Maumy and L. Dunsch, Electrochim. Acta 2005, 50, 1643\u003Cbr \/\u003E\n[11] A. \u00d6sterholm, A. Petr, C. Kvarnstr\u00f6m, A. Ivaska and L. Dunsch, J. Phys. Chem. B 2008, 112, 14149-14157\u003Cbr \/\u003E\n[12] J. Tar\u00e1bek, P. Rapta, M. Kalb\u00e1\u0026#269; and L. Dunsch, Anal. Chem. 2004, 76, 5918 \n\u003C\/p\u003E\n\u003Cp\u003EFor more information contact \u003Ca href=\u0022mailto:jiri.janata@chemistry.gatech.edu\u0022\u003EProf. Art Janata\u003C\/a\u003E (404-894-4828).\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"Dr. Lothar Dunsch, Leibniz-Institute for Solid State and Materials Research (Dresden, Germany)\n\nCharged States in Conducting Polymers as studied by in situ ESR UV\/Vis NIR Spectroelectrochemistry\n\nCOPE Seminar Series","format":"limited_html"}],"field_summary_sentence":[{"value":"Dr. Lothar Dunsch, Leibniz"}],"uid":"27275","created_gmt":"2009-01-26 01:00:00","changed_gmt":"2016-10-08 01:57:16","author":"Shirley Tomes","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2009-02-02T12:45:00-05:00","event_time_end":"2009-02-02T13:45:00-05:00","event_time_end_last":"2009-02-02T13:45:00-05:00","gmt_time_start":"2009-02-02 17:45:00","gmt_time_end":"2009-02-02 18:45:00","gmt_time_end_last":"2009-02-02 18:45:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"related_links":[{"url":"http:\/\/www.ifw-dresden.de\/institutes\/iff\/org\/members\/dunsch","title":"Dr. Lothar Dunsch-Inst. Solid State \u0026 Materials Research"}],"groups":[{"id":"85951","name":"School of Chemistry and Biochemistry"}],"categories":[],"keywords":[{"id":"5468","name":"electromaterials"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1795","name":"Seminar\/Lecture\/Colloquium"}],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cstrong\u003EShirley Tomes\u003C\/strong\u003E\u003Cbr \/\u003EChemistry \u0026amp; Biochemistry\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=st81\u0022\u003EContact Shirley Tomes\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-0591\u003C\/strong\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}