Title of article :
Electronic coupling and photochemical stability of O,N bound mononuclear Ru(II) and Os(II) – Hydroquinone complexes
Author/Authors :
Deirdre Leane، نويسنده , , Tia E. Keyes، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
10
From page :
1627
To page :
1636
Abstract :
The synthesis, spectroscopic and electrochemical characterisation of a series of optically tuneable, ruthenium (II) and osmium (II) polypyridyl complexes, O,N coordinated to electroactive donor ligand, bis-2,5-(2-benzoxazolyl)-hydroquinone (bbhq) is described. The complexes exhibit a rich optical spectroscopy which can be controlled through the redox state of the metal and bbhq ligand. The influence of both the metal and counter-ligand identity on the optical properties of these hydroquinone-based complexes is addressed. Regardless of the identity of metal or counter-ligand, it is the bbhq which is the site of the most facile oxidation and hydroquinone, semiquinone (bbsq) and quinone (bbq) can be generated electrochemically. In each instance, the semiquinone is strongly stabilised with respect to disproportionation, reflected in large stability constants for this moiety. The levels of orbital mixing between metal and ligand are discussed on the basis of the optical properties of the complex and the nature of the metal and counter-ligand. In addition, we address, for the first time, the effect of metal and counter-ligand on the photostability, of Ru(II) and Os(II) hydroquinone bound complexes. We find that like other ruthenium (II) complexes containing strong σ-bonding ligands, the M(bpy)2 containing complexes are photostable, but the [Ru(biq)2(bbhq)]+ complex is relatively photolabile.
Keywords :
ruthenium compounds , Quinone , Spectroelectrochemistry , Non-innocent ligands , Electronic spectroscopy , Hydroquinone
Journal title :
INORGANICA CHIMICA ACTA
Serial Year :
2006
Journal title :
INORGANICA CHIMICA ACTA
Record number :
1323518
Link To Document :
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