159282-60-7Relevant academic research and scientific papers
Silver(I)-mediated isomerisation of trans-[RuCl2(P-P) 2] (P-P =four-membered ring chelate diphosphine ligand) to cis-[{Ru(P-P)2-(μ-Cl)2}nAg]+ species, and applications in stereoselective syntheses of cis- and trans-[RuCl(L)(P-P)2]+ (L = neutral ligand)
Higgins, Simon J.,La Pensee, Annemarie,Stuart, Clare A.,Charnock, John M.
, p. 902 - 910 (2001)
When complexes trans-[RuCl2(diphos)2] (diphos = (Ph2P)2C=CH2, Ph2PCH 2PPh2 or Ph2PNHPPh2) were treated with silver salts of poorly coordinating anions (e.g. AgBF4, AgO 3SCF3) in 1,2-dichloroethane halide abstraction was slow, even at reflux, and the reaction proceeded by an interesting mechanism involving a trans to cis isomerisation. At room temperature, a complex, characterized as [RuCl(diphos)2(μ-Cl)Ag]+, forms. When heated to reflux for 5-10 min this reacts to give a mixture, which includes cis-[RuCl 2(diphos)2], and species of the type [{Ru(diphos) 2(μ-Cl)2}n-Ag]+ (n = 1 or 2) in which the exact coordination geometry at AgI is unknown. The reactions have been followed by 31P-{1H} NMR spectroscopy, and electronic spectroscopy results also support the isomerisation. The ruthenium and silver K-edge EXAFS spectra of the solid isolated from the reaction of trans-[RuCl 2(dppm)2] and AgO3SCF3 lend support to this formulation; in particular, the best fit for the silver(I) environment includes coordination to one oxygen (from the -O3SCF 3; Ru-O 2.43 A), two Cl (2.79 A) and between one and two Ru (3.94 A). Over 30-40 min at reflux, AgCl precipitates, the signals due to cis-[RuCl2(diphos)2] disappear from the 31P-{1H} NMR spectra, those due to the [{Ru(diphos) 2(μ-Cl)2}nAg]+ mixture diminish, and new resonances, attributed to five-coordinate [RuCl(diphos) 2]+, appear. This reaction has been investigated for stereoselective ligand substitution. Treatment of trans-[RuCl 2(diphos)2] with AgBF4 or AgO 3SCF3 in DCE in the presence of CH3CN or CO yields exclusively trans-[RuCl(L)(diphos)2]+ (L = CH 3CN or CO), but treatment of trans-[RuCl2(diphos) 2] with AgBF4 or AgO3SCF3 in DCE, followed by treatment with L, usually gave exclusively cis-[RuCl(L)(diphos) 2]+ (L = CH3CN or CO). The Royal Society of Chemistry 2001.
