The role of isomeric effects on the luminescence lifetimes and electrochemistry of oligothienyl-bridged dinuclear tris(2,2′-bipyridine) ruthenium(II) complexes

Steen, Robert O., Nurkkala, Lasse J., Angus-Dunne, Sarah J., Schmitt, Chantal X., Constable, Edwin C., Riley, Mark J., Bernhardt, Paul V. and Dunne, Simon J. (2008) The role of isomeric effects on the luminescence lifetimes and electrochemistry of oligothienyl-bridged dinuclear tris(2,2′-bipyridine) ruthenium(II) complexes. European Journal of Inorganic Chemistry, 2008 11: 1784-1794. doi:10.1002/ejic.200701118


Author Steen, Robert O.
Nurkkala, Lasse J.
Angus-Dunne, Sarah J.
Schmitt, Chantal X.
Constable, Edwin C.
Riley, Mark J.
Bernhardt, Paul V.
Dunne, Simon J.
Title The role of isomeric effects on the luminescence lifetimes and electrochemistry of oligothienyl-bridged dinuclear tris(2,2′-bipyridine) ruthenium(II) complexes
Journal name European Journal of Inorganic Chemistry   Check publisher's open access policy
ISSN 1434-1948
1099-0682
Publication date 2008-04-01
Year available 2008
Sub-type Article (original research)
DOI 10.1002/ejic.200701118
Open Access Status
Volume 2008
Issue 11
Start page 1784
End page 1794
Total pages 11
Place of publication Weinheim, Germany
Publisher Wiley - VCH Verlag
Language eng
Subject C1
030299 Inorganic Chemistry not elsewhere classified
970103 Expanding Knowledge in the Chemical Sciences
Abstract The luminescence lifetimes (in CH(3)CN at room temperature) and electrochemical potentials (in CH(3)CN) of a range of mono- and bis(bidentate) 2,2'-bipyridine-capped oligo-thiophene-bridged Run complexes based on the 6-(2-thienyl)-2,2'-bipyridine and 4-(2-thienyl)-2,2'-bipyridine motifs have been measured. The redox potentials occurred in a very narrow range and showed only small shifts from that of [Ru(bpy)(3)](2+), which indicates that the inductive effects of the substituents on the 2,2'-bipyridine ligands are very similar across this series. In the complexes that incorporated a bithiophene moiety the oxidation of the bithienyl group occurred at higher potentials than the metal-centered Ru(III/II) oxidation. No or very weak interaction between the metal cores in the dinuclear complexes was observed. It was found that the luminescence lifetimes of the complexes where the attachment point of the oligothiophene bridge is in the 4-position of a 2,2'-bipyridine ligand were extended compared to [Ru(bPY)(3)](2+), whereas the luminescence was very short-lived (<30ns) or completely quenched in the complexes where the oligothiophene bridge was attached in the 6-position. The difference in lifetimes is probably due to steric interactions between the thienyl bridge and the auxiliary bipyridyl ligands, resulting in disturbances in coordination symmetry of the metal core. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Formatted abstract
The luminescence lifetimes (in CH3CN at room temperature) and electrochemical potentials (in CH3CN) of a range of mono- and bis(bidentate) 2,2-bipyridine-capped oligothiophene-bridged RuII complexes based on the 6-(2-thienyl)-2,2-bipyridine and 4-(2-thienyl)-2,2-bipyridine motifs have been measured. The redox potentials occurred in a very narrow range and showed only small shifts from that of [Ru(bpy)3]2+, which indicates that the inductive effects of the substituents on the 2,2-bipyridine ligands are very similar across this series. In the complexes that incorporated a bithiophene moiety the oxidation of the bithienyl group occurred at higher potentials than the metal-centered RuIII/II oxidation. No or very weak interaction between the metal cores in the dinuclear complexes was observed. It was found that the luminescence lifetimes of the complexes where the attachment point of the oligothiophene bridge is in the 4-position of a 2,2-bipyridine ligand were extended compared to [Ru(bpy)3]2+, whereas the luminescence was very short-lived (<30 ns) or completely quenched in the complexes where the oligothiophene bridge was attached in the 6-position. The difference in lifetimes is probably due to steric interactions between the thienyl bridge and the auxiliary bipyridyl ligands, resulting in disturbances in coordination symmetry of the metal core.
Keyword Luminescence
N ligands
Ruthenium
Cyclic voltammetry
Ligand design
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online 20 Feb 2008

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2009 Higher Education Research Data Collection
School of Chemistry and Molecular Biosciences
 
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Created: Thu, 19 Mar 2009, 01:23:10 EST by Jennifer Falknau on behalf of School of Chemistry & Molecular Biosciences