| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1340186 | Polyhedron | 2006 | 10 Pages |
The reaction of 2-(3′-pyridylazo)imidazole (3′-PyaiH) or its 1-alkyl derivative, 3′-PyaiR, with Ru(CO)3(PPh3)2 has synthesized air stable, moisture insensitive, diamagnetic Ru(0) complexes, [Ru(CO)(3′-PyaiR)(PPh3)2]. The ligands serve as an unsymmetric N,N′-chelating agent (N(imidazole) and N(azo) are abbreviated as N and N′, respectively). The X-ray structure determination of [Ru(CO)(3′-PyaiH)(PPh3)2] shows a square pyramidal geometry. The square plane is made up of Ru, 2P, C(O), N(1), and with N(3) at the apex. Other spectroscopic studies (IR, UV–Vis, NMR) support the stereochemistry. Electrochemistry shows three consecutive anodic peaks (Epa) and suggest irreversible redox responses of Ru(I)/Ru(0), Ru(II)/Ru(I), Ru(III)/Ru(II) and azo reductions. Oxidation by Cl2 of [Ru(CO)(3′-PyaiR)(PPh3)2] has isolated the Ru(II)-complex as the perchlorate salt, [Ru(CO)(Cl)(3′-PyaiR)(PPh3)2](ClO4). A solution of RuCl3 and 3′-PyaiR in ethanol has isolated two isomers of the composition Ru(3′-PyaiR)2Cl2. They have been characterized by spectral and electrochemical data.
Graphical abstractRuthenium(II) and ruthenium(0) carbonyl complexes of pyridyl-azo-imidazoles are described. The ligand is an unsymmetric biheterocyclic azo system having an azoimine function. The structure of Ru(CO)-ligand is confirmed by a single crystal X-ray diffraction study in one case along with other spectral data. The Ru(II) complexes exist in two isomeric forms. The redox properties of the complexes are examined by cyclic voltammetry.Figure optionsDownload full-size imageDownload as PowerPoint slide
