Ligands synergistic effects

In systems containing two or more adsorbates, either competitive or synergistic effects may operate. The commonest synergistic effect is that of ternary adsorption (11.5.4). Competitive behaviour may involve competition for the same surface sites, indirect effects due to the change in the electrostatic properties of the oxide/water interface and in some cases, formation of non sorbing, metal-ligand complexes in solution. 

Catalysts for ketone hydrogenation continue to be developed but one of the best systems is still the BINAP-DPEN catalyst first reported by Ohkuma et al. in 1995. " In this system ruthenium is combined with both a chiral diphosphine and a chiral diamine, forming an octahedral complex which gives a high degree of enantioselectivity. This stereoselectivity is considered to be a result of the synergistic effect of the chiral diphosphine and diamine ligands. 

B. Coupez, C. Boehme, and G. Wipff. Importance of interfacial phenomena and synergistic effects in lanthanide cation extraction by dithiophosphinic ligands A molecular dynamics study. J. Phys. Chem. B, 107(35) 9484-9490, 2003. 

Coupez, B., Wipff, G. (2004), The Synergistic Effect of Cobalt-dicarbollide Anions on the Extraction of M Lanthanide Cations by Calix[4]arene-CMPO ligands a Molecular Dynamics Study at the Water-"oil" Interface, C. R. Chimie Acad. Sc. Paris, in press. 

Coupez, B., Boehme, C., Wipff, G. (2003), Importance of Interfacial Phenomena and Synergistic Effects in Cation Extraction by Dithiophosphinic Ligands a Molecular Dynamics Study, /. Phys. Chem. B 107, 9484-9490. 

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