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Refractory metals have high melting points, with tungsten and rhenium the highest of all elements, and the other's melting points only exceeded by osmium and iridium, and the sublimation of carbon. These high melting points define most of their applications. All the metals are body-centered cubic except rhenium which is hexagonal close-packed.
Rhenium has one stable isotope, rhenium-185, which nevertheless occurs in minority abundance, a situation found only in two other elements (indium and tellurium). Naturally occurring rhenium is only 37.4% 185 Re, and 62.6% 187 Re, which is unstable but has a very long half-life (~10 10 years).
Oxotrichlorobis(triphenylphosphine)rhenium(V) is the chemical compound with the formula Re O Cl 3 (P Ph 3) 2. This yellow, air-stable solid is a precursor to a variety of other rhenium complexes. [1] In this diamagnetic compound, Re has an octahedral coordination environment with one oxo, three chloro and two mutually trans triphenylphosphine ...
Rhenium(VI) oxide has an appearance similar to that of copper. Rhenium(IV) oxide (or rhenium dioxide) is an oxide of rhenium, with the formula ReO 2. This gray to black crystalline solid is a laboratory reagent that can be used as a catalyst. It adopts the rutile structure. It forms via comproportionation: [4] 2 Re 2 O 7 + 3 Re → 7 ReO 2
Perrhenic acid is the chemical compound with the formula Re 2 O 7 (H 2 O) 2.It is obtained by evaporating aqueous solutions of Re 2 O 7.Conventionally, perrhenic acid is considered to have the formula HReO 4, and a species of this formula forms when rhenium(VII) oxide sublimes in the presence of water or steam. [2]
It is the raw material for all rhenium compounds, being the volatile fraction obtained upon roasting the host ore. [26] Rhenium, in addition to the +4 and +7 oxidation states, also forms a trioxide. It can be formed by reducing rhenium(VII) oxide with carbon monoxide at 200 C or elemental rhenium at 4000 C. [27] It can also be reduced with ...
Pages in category "Rhenium compounds" The following 29 pages are in this category, out of 29 total. This list may not reflect recent changes. O. Organorhenium chemistry;
Rhenium(VII) sulfide is a chemical compound with the formula Re 2 S 7.It has a complex structure, but can be synthesized from direct combination of the elements: [1] + Alternatively, rhenium(VII) oxide reacts with hydrogen sulfide in 4N HCl to the same end: [2] + +