Rhenium complexes bidentate phosphines

Tris(l,2-bis(dimethylphosphino)ethane)rhenium(I), [Re(DMPE)3]+ is a simple, symmetrical cation which contains three identical bidentate phosphine ligands. This complex provides a Re(II/I) redox couple with properties that are very convenient for the study of outer-sphere electron transfer reactions.1 Specifically, this couple is stable in both alkaline and acidic media and it exhibits a reversible, one-equivalent redox potential in an accessible region [ °,(II/I) = 565 mV vs. NHE]. Moreover, this complex has been used to obtain information about the biological mechanism of action of 186Re and l88Re radiopharmaceuticals.2,3... 

Complexes of the type ReX4(LL) containing bidentate phosphine and arsine ligands have been prepared by two general methods. The halocarbon oxidation of the rhenium(III) complexes Re2(/<-... 

The hydrosilylation of carbonyl confounds with Et3SiH (eq 4) has also been the subject of additional research. Owing to these efforts, carbonyls can now be directly converted to their tri-ethylsilyl (TES) ethers with copper catalysts in the company of a bidentate phosphine or Al-heterocycUc carbene ligand. Tri-ethylsilyl ethers can also be made from carbonyl compounds and EtsSiH in the presence of rhenium(V) oxo-complexes. ... 

Rhenium(IV) complexes with only one bidentate ligand have been described for chelating phosphines, Schiff bases, and A-heterocycles. The synthetic approaches are different and involve simple ligand exchange procedures as well as reduction of rhenium(V) or oxidation of rhe-nium(III) compounds. 

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