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Long‐Lived MLCT Excited States‐Ru II Complexes with a Helical Bis‐Phen Ligand
Author(s) -
Goze Christine,
Chambron JeanClaude,
Heitz Valérie,
Pomeranc Didier,
SalomRoig Xavier J.,
Sauvage JeanPierre,
Morales Angeles Farrán,
Barigelletti Francesco
Publication year - 2003
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200300161
Subject(s) - chemistry , luminescence , excited state , ligand (biochemistry) , crystallography , ruthenium , crystal structure , metal , stereochemistry , atomic physics , catalysis , biochemistry , physics , receptor , optoelectronics , organic chemistry
The synthesis of a new Ru II complex [Ru( L 1 )(4,7‐dpphen)] 2+ , bearing a tetradentate bis‐1,10‐phenanthroline ligand L 1 , is described. X‐ray crystal structure analysis shows that the tetradentate ligand L 1 coils around the metal and occupies both axial and two of the equatorial positions of the complex. 1 H NMR studies clearly indicate that the complex has C 2 symmetry in solution. The room temperature luminescence properties of [Ru( L 1 )(4,7‐dpphen)] 2+ have been studied, as have those of the related complex [Ru( L 2 )(4,4′‐dmbp)] 2+ . For both complexes, the luminescence quantum yields and lifetimes are three to ten times higher than those of [Ru(bpy) 3 ] 2+ . These unusual results are explained by the geometrical constraints imposed by the tetradentate ligands L 1 and L 2 in their respective complexes, resulting in an effective decoupling between the 3 MLCT and 3 MC excited states. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)