Electronic Energy Transfer and Collection in Luminescent Molecular Rods Containing Ruthenium(II) and Osmium(II) 2,2′:6′,2″-Terpyridine Complexes Linked by Thiophene-2,5-diyl Spacers

Os directional transfer of excitation energy takes place in the complexes [(tpy)Ru(3)Os(tpy)]4+ (end-to-end) and [(tpy)Ru(3)Os(3)Ru(tpy)]6+ (periphery-to-centre). With respect to the homometallic case, for [(tpy)Ru(3)Os(3)Ru(tpy)]6+ excitation trapping at the central position is accompanied by a fivefold enhancement of luminescence intensity. -->
ISSN: 1521-3765
0947-6539
DOI: 10.1002/1521-3765(20020104)8:1<137::aid-chem137>3.0.co;2-x
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::572a96874dd71bbf0b442f3136726001
https://doi.org/10.1002/1521-3765(20020104)8:1<137::aid-chem137>3.0.co;2-x
Rights: CLOSED
Přírůstkové číslo: edsair.doi.dedup.....572a96874dd71bbf0b442f3136726001
Autor: Emma R. Schofield, Catherine E. Housecroft, Lucia Flamigni, Francesco Barigelletti, Edwin C. Constable, Dieter Fenske, Margareta Zehnder, Markus Neuburger, Johannes G. Vos, Egbert Figgemeier, Susana Encinas
Rok vydání: 2002
Předmět:
Zdroj: Chemistry - A European Journal. 8:137-150
ISSN: 1521-3765
0947-6539
DOI: 10.1002/1521-3765(20020104)8:1<137::aid-chem137>3.0.co;2-x
Popis: The electronic absorption spectra, luminescence spectra and lifetimes (in MeCN at room temperature and in frozen n-C3H7CN at 77 K), and electrochemical potentials (in MeCN) of the novel dinuclear [(tpy)Ru(3)Os(tpy)]4+ and trinuclear [(tpy)Ru(3)Os(3)Ru(tpy)]6- complexes (3 = 2,5-bis(2,2':6',2''-terpyridin-4-yl)thiophene) have been obtained and are compared with those of model mononuclear complexes and homometallic [(tpy)Ru(3)Ru(tpy)]4+, [(tpy)Os(3)Os(tpy)]4+ and [(tpy)Ru(3)Ru(3)Ru(tpy)]6+ Complexes. The bridging ligand 3 is nearly planar in the complexes, as seen from a preliminary X-ray determination of [(tpy)Ru(3)Ru(tpy)][PF6]4, and confers a high degree of rigidity upon the polynuclear species. The trinuclear species are rod-shaped with a distance of about 3 nm between the terminal metal centres. For the polynuclear complexes, the spectroscopic and electrochemical data are in accord with a significant intermetal interaction. All of the complexes are luminescent (phi in the range 10(-4)-10(-2) and tau in the range 6-340 ns, at room temperature), and ruthenium- or osmium-based luminescence properties can be identified. Due to the excited state properties of the various components and to the geometric and electronic properties of the bridge, Ru --> Os directional transfer of excitation energy takes place in the complexes [(tpy)Ru(3)Os(tpy)]4+ (end-to-end) and [(tpy)Ru(3)Os(3)Ru(tpy)]6+ (periphery-to-centre). With respect to the homometallic case, for [(tpy)Ru(3)Os(3)Ru(tpy)]6+ excitation trapping at the central position is accompanied by a fivefold enhancement of luminescence intensity.
Databáze: OpenAIRE
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