Synthesis, spectroscopy and electrochemistry of a #mu#-oxo-triruthenium cluster containing a bridted bis(2,2'-bipyridyl)ruthenium(II) moiety

摘要

A bridged cluster species of formula (Ru_3O(CH_3COO)_6(py)_2(4,4'-bpy)Ru(bpy)_2(Cl)](PF_6)_2 (py = pyridine, bpy = 2,2'-bipyridine, 4,4'-bpy = 4,4'-bipyridine) has been synthesized and characterized based on electronic and 2D NMR spectroscopy, cyclic voltammetry and UV -Vis spectroelectrochemistry .The electronic spectra of the complex exhibit the characteristic MLCT band ..for the [Ru(bpy)_2Cl]~+ moiety at 489 nm, and a broad band at 692 nm ascribed to [RU_3O] internal core transitions. The complex exhibit a reversible multistep redox behavior in the range from -1.5 to 2.5 V (SHE), consisting of five monoelectronic waves at -1.31, -1.06,0.15, 1.17 and 2.09 V ascribed to (RU_3O] core redox processes, and at 0.98 V ascribed to the (Ru(bpy)_2Cl]~(+/+2) redox couple. Both Ru~(+ 2/ + 3) pair and (RU3O]~(-1/0/+1) processes are influenced significantly by the electronic interactions through the 4,4'-bipyridine bridging ligand.