Because rhenium is a rare element, relatively few applications exist, but the area has been a rich source of concepts and a few useful catalysts.
A noteworthy feature of organorhenium chemistry is the coexistence of oxide and organic ligands in the same coordination sphere.
In refluxing water, it forms the triaquo cation:[5] With tetraethylammonium bromide Re(CO)5Br reacts to give the anionic tribromide:[6] One of the first transition metal hydride complexes to be reported was (C5H5)2ReH.
Well known is methylrhenium trioxide ("MTO"), CH3ReO3 a volatile, colourless solid, a rare example of a stable high-oxidation state metal alkyl complex.
[8] MTO and other organylrhenium trioxides catalyze oxidation reactions with hydrogen peroxide as well as olefin metathesis in the presence of a Lewis acid activator.