Rhenate , with

Ebner and Walton have investigated the reduction of octahalodi-rhenate(III) dimers with a variety of phosphines (124). Simple substitution reactions are observed under mild conditions to form RegX Rs as is noted... 

Analogously, the reaction of rhenate pentacarbonyl anion [Re(CO)5] as its sodium salt, with cyclopropenylium cations [C3Ph3]X (X = BF4, PF6) in THF, at -80 °C, afforded the octahedral n-coordinated pentacarbonyl ( /-l,2,3-triphenylcyclopropenyl)rhenium complex in 60-73% yield (equation 195)26 269. The l3C NMR (acetone-, .) spectrum dis-... 

Isomerization of a /Jtri mcth y I si I y I propargy 1 alcohol to give the ,/J-unsaluraled acyl silane via the intermediate enol form, the 1-hydroxy-1-trimethylsilylallene, occurs upon treatment with tetrabutylammonium per-rhenate and p-toluenesulphonic acid144. While several examples of the isomerization reaction are given, only one is able to give an acyl silane product. 

The salt reacts rapidly with water precipitating some of the platinum as hydrated dioxide, most of it remaining in solution as hexafluoroplatinate(iv). This behaviour resembles the reductive interaction of the hexafluoro-rhenates(v)-osmates(v) and -iridates(v), with water to give the quadripositive fluorosalts. Since the latter cannot be synthesized in aqueous media, they are probably thermod5mamically unstable with respect to hydrolysis. If so, evidently the hexafluoroplatinate(v) ion must remain intact during reduction to the hexafluoroplatinate(iv) ion. 

Treatment with potassium metal of a suspension of potassium per-rhenate in ethylenediamine containing a little water precipitates a brown powder that may be purified (with considerable difficulty) by repeated extraction with 2-propanol, followed by dissolution in potassium hydroxide and reprecipitation with 98% ethylenediamine (28, 95, 112). The final product is a diamagnetic white deliquescent solid that undergoes slow decomposition on exposure to the atmosphere. 

There is a quite extensive chemistry associated with the so-called mesoperrhenates and orthoper-rhenates, which are derivatives of the [ReOj] " and [ReOg] anions, and various mixed metal oxides. These phases have been surveyed in some detail in Ae review by Rouschias. More recent developments have included studies on rhenium-apatites containing the square pyramidal [ReOj] unit, hexagonal perovskites with cation vacancies that contain [ReOs] , and the double oxides M3Rc2O 0 (M = Sr or Ba) and MsRe20 2 (M = Ca or Sr). ... 

---