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Electron delocalization in vinyl ruthenium substituted cyclophanes: Assessment of the through-space and the through-bond pathways
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SYSNO ASEP 0369086 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Electron delocalization in vinyl ruthenium substituted cyclophanes: Assessment of the through-space and the through-bond pathways Author(s) Mücke, P. (DE)
Zabel, M. (DE)
Edge, R. (GB)
Collison, D. (GB)
Clément, S. (FR)
Záliš, Stanislav (UFCH-W) RID, ORCID
Winter, R. F. (DE)Source Title Journal of Organometallic Chemistry. - : Elsevier - ISSN 0022-328X
Roč. 696, č. 20 (2011), s. 3186-3197Number of pages 12 s. Language eng - English Country CH - Switzerland Keywords electrochemistry ; vinyl complexes ; ruthenium Subject RIV CG - Electrochemistry R&D Projects LD11086 GA MŠMT - Ministry of Education, Youth and Sports (MEYS) KAN100400702 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR) CEZ AV0Z40400503 - UFCH-W (2005-2011) UT WOS 000293999500010 DOI 10.1016/j.jorganchem.2011.06.028 Annotation Pseudo-para[2.2]paracyclophane- and [2.1]orthocyclophane-bridged diruthenium complexes 2 and 3 with two interlinked electroactive styryl ruthenium moieties have been prepared and investigated. Both complexes undergo two reversible consecutive one-electron oxidation processes which are separated by 270 or 105 mV. Stepwise electrolysis of the neutral complexes to first the mixed-valent radical cations and then the dioxidized dications under IR monitoring reveal incremental shifts of the charge-sensitive Ru(CO) bands and allow for an assignment of their radical cations as moderately or very weakly coupled mixed-valent systems of class II according to Robin and Day. Ground-state delocalization in the mixed-valent forms of these complexes as based on the CO band shifts is considerably larger for the "closed" paracyclophane as for the "half-open" orthocyclophane. Experimental findings are backed by the calculated IR band patterns and spin density distributions for radical cations of slightly simplified model complexes 2Me(.+) and 3Me(.+) with the P(i)Pr(3) ligands replaced by PMe(3). Radical cations 2(.+) and 3(.+) feature a characteristic NIR band that is neither present in their neutral or fully oxidized forms nor in the radical cation of the monoruthenium [2.2] paracyclophane complex 1 with just one vinyl ruthenium moiety. These bands are thus assigned as intervalence charge-transfer (IVCT) transitions. Our results indicate that, for the radical cations, electronic coupling "through-space" via the stacked styrene decks is significantly more efficient than the "through-bond" pathway. Workplace J. Heyrovsky Institute of Physical Chemistry Contact Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Year of Publishing 2012
Number of the records: 1