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Synthesis and Properties of Dinuclear Complexes with a Photochromic Bridge: An Intervalence Electron Transfer Switching “On” and “Off”

2000; Wiley; Volume: 2000; Issue: 7 Linguagem: Inglês

10.1002/1099-0682(200007)2000

1099-0682

Sandrine Fraysse, Christophe Coudret, Jean‐Pierre Launay,

Radical Photochemical Reactions

European Journal of Inorganic ChemistryVolume 2000, Issue 7 p. 1581-1590 Full Paper Synthesis and Properties of Dinuclear Complexes with a Photochromic Bridge: An Intervalence Electron Transfer Switching “On” and “Off” Sandrine Fraysse, Sandrine Fraysse Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France, Fax: (internat.) + 33-5/62257999Search for more papers by this authorChristophe Coudret, Christophe Coudret [email protected] Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France, Fax: (internat.) + 33-5/62257999Search for more papers by this authorJean-Pierre Launay, Jean-Pierre Launay Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France, Fax: (internat.) + 33-5/62257999Search for more papers by this author Sandrine Fraysse, Sandrine Fraysse Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France, Fax: (internat.) + 33-5/62257999Search for more papers by this authorChristophe Coudret, Christophe Coudret [email protected] Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France, Fax: (internat.) + 33-5/62257999Search for more papers by this authorJean-Pierre Launay, Jean-Pierre Launay Centre d’Elaboration de Matériaux et d’Etudes Structurales, CNRS, 29 rue Jeanne Marvig, 31055 Toulouse Cedex, France, Fax: (internat.) + 33-5/62257999Search for more papers by this author First published: July 2000 https://doi.org/10.1002/1099-0682(200007)2000:7 3.0.CO;2-2Citations: 195AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Two cyclometallated Ru(bpy)2(pp) units (bpy = 2,2′-bipyridine; pp = 2-phenylpyridine) were grafted via ethynyl spacers onto the photochromic cores of the norbornadiene or dithienylethene families, to give the bimetallic ruthenium(II) complexes 1 and 2a, respectively. Two aspects of these compounds were studied: (i) photoisomerization (norbornadiene to quadricyclane for 1, open form to closed form of the dithienylethene core for 2a), and (ii) intervalence transitions in the mixed-valence ruthenium(II−III) state, with determination of the metal−metal electronic coupling (Vab) by Hush’s equation. Moderate metal−metal electronic coupling (0.068 eV) was found for 1, but 1 cannot be isomerized into the quadricyclane form. On the other hand, 2a can be reversibly photoisomerized to the closed form 2b. An iodine(III) reagent, the triflate salt of bis(pyridyl)phenyliodonium, was used for the oxidation of 2a and 2b. During these oxidations, an intervalence band due to intramolecular electron transfer between ruthenium(II) and ruthenium(III) was detected for 2b, but not for 2a. This switching “on” or “off” of the intervalence transition is rationalized with extended Hückel calculations. Finally, the molecular orbital calculation explains the observed tendency of the closed form 2b to reopen upon oxidation. References [1] Google Scholar [1a] For an overview of molecular electronics see, for instance: Molecular Electronics: Science and Technology (Eds.: A. Aviram, M. Ratner), Annals NY Acad. Sci. 1998, 852, and references therein. − Google Scholar [1b] C. Joachim, J. K. Gimzewski, Chem. Phys. Lett. 1997, 265, 353. − Google Scholar [1c] A. Gourdon, H. Tang, in Molecular Electronics: Science and Technology (Eds.: A. Aviram, M. Ratner), Annals NY Acad. 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