117227-72-2

Upstream product

• 117227-65-3 bis(acetonitrile)bis(salicylaldehydato)ruthenium(III) hexafluorophosphate 
• 15529-49-4 tris(triphenylphosphine)ruthenium(II) chloride 
• 90-02-8 salicylaldehyde 

Relevant academic research and scientific papers

Ligand control of metal oxidation states. Synthesis, characterization and cyclic voltammetric studies of a group of ruthenium phenolates

Reaction of a series of phenolic ligands with different functional groups at the 2-position with [Ru(PPh3)3Cl2] affords stable complexes of ruthenium(II) and ruthenium (III). The ruthenium(II) complexes are diamagnetic and show intense absorption in the visible region due to MLCT transitions. In dichloromethane solution, the complexes show redox (ruthenium(II)-ruthenium(III)) behaviour, the potential of which varies with the electronic nature of the phenolic ligand. In two of these complexes, an irreversible ruthenium(III)-ruthenium(IV) oxidation was observed near 1.2 V (vs SCE). The ruthenium(III) complexes are one-electron paramagnetic showing rhombic ESR spectra at 77 K. Intense LMCT transitions were observed in the visible region together with low-intensity ligand-field transitions at lower energies. In acetonitrile solution the ruthenium (III) complexes show both ruthenium(III)-ruthenium(II) reduction and ruthenium(III)-ruthenium(IV) oxidation.

Ruthenium phenolates. Chemistry of a family of RuIIIO6 tris chelates

Tris chelates of ruthenium(III), RuL3 (2), with o-formyl- and o-acylphenols are reported. The structure of the salicylaldehydato complex, Ru(sal)3, has been determined by three-dimensional X-ray crystallography. The crystals are monoclinic in space group P21/n with Z = 4 and unit cell dimensions a = 9.718 (2) ?, b = 10.178 (2) ?, c = 18.800 (4) ?, β = 98.42 (2)°, and V = 1839.6 (6) ?3. The structure was refined to R = 0.0332 and Rw = 0.0455. The RuO6 coordination sphere is nearly octahedral and has meridional configuration. The coordinated sal ligands are planar, but the ruthenium atom does not lie in the plane of any of the sal ligands due to a fold along the O,O line of each Ru(sal) fragment. The average Ru-O(phenolato) and Ru-O(carbonyl) distances are respectively 1.981 (2) and 2.031 (2) ?. There is a subtle form of dimerization due to two contacts of the type C-H?O between the aldehyde functions of two ligands located on two symmetry-related molecules. The low-spin (S = 1/2) RuL3 complexes display rhombic EPR spectra characterized by axial and rhombic distortion parameters of ～4500 and ～1500 cm-1, respectively. In the axial limit the ground state of the molecule is e4a1. An absorption band observed near 5600 cm-1 is assigned to an optical transition between two Kramers doublets. Primary amines convert Ru(sal)3 to Schiff base tris chelates (4) stereoretentively. In acetonitrile the quasi-reversible coupled RuIVL3+-RuIIIL3 and RuIIIL3-RuIIL3- are observed. The RuIVL3+ cation undergoes spontaneous reduction with partial ligand displacement to afford RuIIIL2(MeCN)2+, which is a good synthetic precursor for complexes of the RuL2 fragment. Reductive ligand displacement also occurs when RuL3 reacts with 2,2′-bipyridine (bpy) in ethanol, affording RuIIL2(bpy). The trivalent state can be reestablished as in RuIII(sal)2(bpy)+ by oxidation with cerium(IV). The complex RuII(sal)(bpy)2+ is also reported. In the series Ru(sal)3-n(bpy)nz (n = 0-3), the replacement of each sal ligand by a bpy ligand shifts the ruthenium(III)-ruthenium(II) formal potential upward by ～0.6 V.