Co-ordination chemistry of mixed pyridine–phenol ligands; electrochemical, electron paramagnetic resonance and structural studies on monounclear ruthenium(III) and chromium(III) complexes
- 1 January 1993
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in J. Chem. Soc., Dalton Trans.
- No. 15,p. 2321-2327
- https://doi.org/10.1039/dt9930002321
Abstract
Syntheses of the new complexes [RuL1 3]1, [Rul1 2(acac)]2, [RuL1 2(bipy)][PF6]3, [CrL1 3]4, [CrL1 2(acac)]5 and [CrL2 2][PF6]6[HL1= 2-(2-hydroxyphenyl)pyridine, HL2= 6-(2-hydroxyphenyl)-2,2′-bipyridine, Hacac = pentane-2,4-dione, bipY = 2,2′-bipyridine] have been carried out. The ruthenium(III) complexes 1–3 all show reversible +3/+4 and +2/+3 waves in their cyclic voltammograms. Together with some previously reported complexes, a full set of electrochemical data is now available for ruthenium complexes with donor sets varying from N6 to N3O3(where N denotes a pyridyl donor and O a phenolate donor); there is a monotonic decrease of 0.75 V in the RuII-RuIII couple per additional phenolate in the co-ordination sphere. Both 1 and 2 have typical rhombic EPR spectra, but the spectrum of 3 is only consistent with formation of a mixture of cis and trans isomers. The chromium(III) complexes show similar variations in the potentials of their metal-centred reductions with donor set although the relationship is not linear. X-Ray analysis showed the both 4 and 6 have pseudo-octahedral crystal structures. Complex 4 crystallises in the chiral space group Fdd2 and therefore spontaneously resolves on crystallisation; 6 has a π-stacking interaction between aromatic residues of adjacent complex units, with an average separation of 3.71 Å between the atoms of one aromatic ring and the mean plane of the other.Keywords
This publication has 20 references indexed in Scilit:
- Synthesis, spectra and electrochemistry of ruthenium(III) complexes with cage-like Schiff-base ligandsPolyhedron, 1992
- The co-ordination chemistry of mixed pyridine–phenol ligands; synthesis of 6-(2-hydroxyphenyl)-2,2′-bipyridine (HL) and the crystal structures of [Cu2L2(µ-MeCO2)][PF6]·1.5CH2Cl2and [CoL2][PF6]·MeCNJ. Chem. Soc., Dalton Trans., 1992
- The co-ordination chemistry of mixed pyridine–phenol and phenanthroline–phenol ligands; effects of π-stacking interactions and ligand rigidity on complex structuresJ. Chem. Soc., Dalton Trans., 1992
- Co-ordination chemistry of mixed pyridine–phenol ligands; the crystal structure of [{NiL(HL)}2][PF6]2·0.5MeCN·0.5Et2O [HL =6-(2-hydroxyphenyl)-2,2′-bipyridine]J. Chem. Soc., Dalton Trans., 1992
- The co-ordination chemistry of mixed pyridine–phenol ligands; spectroscopic and redox properties of mononuclear ruthenium complexes with (pyridine)6–x(phenolate)xdonor sets (x= 1 or 2)J. Chem. Soc., Dalton Trans., 1992
- Co-ordination chemistry of mixed pyridine–phenol and phenanthroline–phenol ligands; a variable-temperature electron paramagnetic resonance and magnetic susceptibility study on two binuclear copper(II) complexes with Cu2(µ-O)2(µ-1,3,-O2CMe) coresJ. Chem. Soc., Dalton Trans., 1992
- Ruthenium and osmium complexes of N,O chelators: syntheses, oxidation levels, and distortion parametersInorganic Chemistry, 1987
- The preparation, isolation and properties of tris(8-quinolinolato-N1,O8)ruthenium(III)Inorganica Chimica Acta, 1985
- Ruthenium complexes with a tetradentate salicylaldimine Schiff baseAustralian Journal of Chemistry, 1978
- Chiral chromium(III) and ruthenium(III) complexes of salicylaldimine ligandsInorganica Chimica Acta, 1974