Editing Group 7 element (section)

==== Rhenium ====

{{Main article|Organorhenium chemistry}}

[[Dirhenium decacarbonyl]] is the most common entry to organorhenium chemistry. Its reduction with sodium [[Amalgam (chemistry)|amalgam]] gives Na[Re(CO)<sub>5</sub>] with rhenium in the formal oxidation state −1.<ref>{{cite journal|doi = 10.1002/cber.19901230103|title = Nucleophile Addition von Carbonylmetallaten an kationische Alkin-Komplexe [CpL2M(η2-RC≡CR)]+ (M = Ru, Fe): μ-η1:η1-Alkin-verbrückte Komplexe|date = 1990|author = Breimair, Josef|journal = Chemische Berichte|volume = 123|page = 7|last2 = Steimann|first2 = Manfred|last3 = Wagner|first3 = Barbara|last4 = Beck|first4 = Wolfgang}}</ref> Dirhenium decacarbonyl can be oxidised with [[bromine]] to [[bromopentacarbonylrhenium(I)]]:<ref>{{cite book|title=Inorganic Syntheses|first=Steven P.|last =Schmidt|author2=Trogler, William C. |author3=Basolo, Fred |chapter=Pentacarbonylrhenium Halides | volume=28|date=1990|pages=154–159|doi=10.1002/9780470132593.ch42|isbn=978-0-470-13259-3}}</ref>
:Re<sub>2</sub>(CO)<sub>10</sub> + Br<sub>2</sub> → 2 Re(CO)<sub>5</sub>Br

Reduction of this pentacarbonyl with [[zinc]] and [[acetic acid]] gives [[pentacarbonylhydridorhenium]]:<ref name="Urb">{{cite book|author=Michael A. Urbancic|author2=John R. Shapley|chapter=Pentacarbonylhydridorhenium |title=Inorganic Syntheses|volume=28|pages=165–168|date=1990|doi =10.1002/9780470132593.ch43|isbn=978-0-470-13259-3}}</ref>
:Re(CO)<sub>5</sub>Br + Zn + HOAc → Re(CO)<sub>5</sub>H + ZnBr(OAc)

[[Methylrhenium trioxide]] ("MTO"), CH<sub>3</sub>ReO<sub>3</sub> is a volatile, colourless solid has been used as a [[catalyst]] in some laboratory experiments. It can be prepared by many routes, a typical method is the reaction of Re<sub>2</sub>O<sub>7</sub> and [[tetramethyltin]]:
:Re<sub>2</sub>O<sub>7</sub> + (CH<sub>3</sub>)<sub>4</sub>Sn → CH<sub>3</sub>ReO<sub>3</sub> + (CH<sub>3</sub>)<sub>3</sub>SnOReO<sub>3</sub>
Analogous alkyl and aryl derivatives are known. MTO catalyses for the oxidations with [[hydrogen peroxide]]. Terminal [[alkyne]]s yield the corresponding acid or ester, internal alkynes yield diketones, and [[alkene]]s give epoxides. MTO also catalyses the conversion of [[aldehyde]]s and [[diazoalkane]]s into an alkene.<ref>Hudson, A. (2002) “Methyltrioxorhenium” in ''Encyclopedia of Reagents for Organic Synthesis''. John Wiley & Sons: New York, {{ISBN|9780470842898}}, {{doi|10.1002/047084289X}}.</ref>