Title: Methyltrioxorhenium
CAS Registry Number: 70197-13-6
CAS Name: (T-4)-Methyltrioxorhenium
Additional Names: MTO
Molecular Formula: CH3O3Re
Molecular Weight: 249.24
Percent Composition: C 4.82%, H 1.21%, O 19.26%, Re 74.71%
Line Formula: CH3ReO3
Literature References: Acts as an oxidation catalyst by transferring an oxygen atom from one species to another; hydrogen peroxide is often the oxygen source. Prepn: I. R. Beattie, P. J. Jones, Inorg. Chem. 18, 2318 (1979); W. A. Herrmann et al., Angew. Chem. Int. Ed. 27, 394 (1988). Catalytic uses: idem et al., ibid. 30, 1636, 1638, 1641 (1991). Photochemistry studies: H. Kunkely et al., Organometallics 10, 2090 (1991); L. J. Morris et al., ibid. 20, 2344 (2001). Review of catalytic chemistry: J. H. Espenson, Chem. Commun. 1999, 479-488; F. E. Kühn, W. A. Herrmann, Chemtracts Org. Chem. 14, 59-83 (2001).
Properties: Colorless solid, mp 110°. d23 4.21. Sol in acetonitrile, benzene, chloroform, ethanol, ether. Sparingly sol in carbon disulfide, hexane. Soly at 25° (g/l): water ~50; forms a golden ppt, poly-MTO. uv max (hexane): 205, 231, 260 nm (e 1600, 1500, 1020). uv max (aqueous): 239, 270 nm (e 1900, 1300). Air and moisture stable, Tdec >300°.
Melting point: Colorless solid, mp 110°
Absorption maximum: uv max (hexane): 205, 231, 260 nm (e 1600, 1500, 1020); uv max (aqueous): 239, 270 nm (e 1900, 1300)
Density: d23 4.21
Derivative Type: Poly-MTO
Line Formula: H0.5[(CH3)0.92ReO3]n
Literature References: First known "polymeric" organometallic oxide. Formed by MTO in aqueous soln. Prepn: W. A. Hermann, R. W. Fischer, J. Am. Chem. Soc. 117, 3223 (1995). Structural study: idem et al., ibid. 3231.
Properties: Golden solid with graphite-like consistence and reflectance. d23 4.38. Insol in practically all inorganic and organic solvents. Electric resistivity (25°): 6´10-3 W cm.
Density: d23 4.38
Use: Versatile organometallic catalyst active in oxidation reactions, olefin isomerization, epoxidation and metathesis. |