The tetranuclear ruthenium complex {Ru[(tpphz)Ru(bpy)2]3}8+, where tpphz is tetrapyrido[3,2-a:2′ ,3′ -c:3″ 2″ -h:2‴ ,3‴ -j]phenazine, has been synthesized by reaction of [Ru(tpphz)3]2+ with [Ru(bpy)2Cl2] and by reaction of [Ru(bpy)2(tpphz)]2+ with [Ru(DMSO)4Cl2]. The large distance between the chiral centers allows full 1H NMR interpretation despite the mixture of eight stereoisomers. The tetranuclear complex was further characterized by electrospray mass spectrometry and by the wide-angle X-ray scattering technique, which confirmed the starburst geometry. The photophysical properties of the tetranuclear complex in acetonitrile were studied and compared with those of [Ru(tpphz)3]2+ (1 × 10-4 M acidic solution) and [(bpy)2Ru(tpphz)Ru(bpy)2]4+ model molecules. The tetranuclear complex gives rise to a single emission, attributed to metal-to-ligand charge-transfer states involving peripheral Ru centers and tpphz bridging ligands.
Tetranuclear tetrapyrido[3,2-a:2’,3’-c:3”,2”-h:2’’’-3’’’-j]phenazineruthenium Complex: Synthesis, Wide-Angle X-ray Scattering, and Photophysical Studies
CHIORBOLI, Claudio;SCANDOLA, Franco;BIGNOZZI, Carlo Alberto
1998
Abstract
The tetranuclear ruthenium complex {Ru[(tpphz)Ru(bpy)2]3}8+, where tpphz is tetrapyrido[3,2-a:2′ ,3′ -c:3″ 2″ -h:2‴ ,3‴ -j]phenazine, has been synthesized by reaction of [Ru(tpphz)3]2+ with [Ru(bpy)2Cl2] and by reaction of [Ru(bpy)2(tpphz)]2+ with [Ru(DMSO)4Cl2]. The large distance between the chiral centers allows full 1H NMR interpretation despite the mixture of eight stereoisomers. The tetranuclear complex was further characterized by electrospray mass spectrometry and by the wide-angle X-ray scattering technique, which confirmed the starburst geometry. The photophysical properties of the tetranuclear complex in acetonitrile were studied and compared with those of [Ru(tpphz)3]2+ (1 × 10-4 M acidic solution) and [(bpy)2Ru(tpphz)Ru(bpy)2]4+ model molecules. The tetranuclear complex gives rise to a single emission, attributed to metal-to-ligand charge-transfer states involving peripheral Ru centers and tpphz bridging ligands.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
