Pentamethylcyclopentadienyl ruthenium(II) complexes of para-substituted N-(pyrid-2-ylmethylene)-phenylamine ligands:: syntheses, spectral and structural studies

The reaction of [(eta(5) -C5Me5)Ru(PPh3)(2)Cl] (1) with acetonitrile in the presence of excess NH4PF6 leads to the formation of the cationic ruthenium(II) complex [(eta(5) -C5Me5)Ru(PPh3)(2)(CH3CN)]PF6 (2). The complex (2) reacts with a series of N,N' donor Schiff base ligands viz. para-substituted N-(pyrid-2-ylmethylene)-phenylamines (ppa) in methanol to yield pentamethylcylopentadienyl ruthenium(II) Schiff base complexes of the formulation [(eta(5) -C5Me5)Ru(PPh3)(C5H4N-2-CH=N-C6H4-p-X)]PF6 [3a]PF6-[3f]PF6, where C5Me5 = pentamethylcylopentadienyl, X = H, [3a]PF6, Me, [3b]PF6, OMe, [3c]PF6, NO2, [3d]PF6, Cl, [3e]PF6, COOH, [3f]PF6. The complexes were isolated as their hexafluorophosphate salts. The complexes were fully characterized on the basis of elemental analyses and NMR spectroscopy. The molecular structure of a representative complex, [(eta5 -C5Me5)Ru(PPh3)(C5H4N-2-CH=N-C6H4-P-Cl)]PF6 [3e]PF6, has been established by X-ray crystallography. (C) 2004 Elsevier Ltd. All rights reserved.