Titanocene dicarbonyl explained

Dicarbonylbis(cyclopentadienyl)titanium is the chemical compound with the formula (η⁵-C₅H₅)₂Ti(CO)₂, abbreviated Cp₂Ti(CO)₂. This maroon-coloured, air-sensitive species is soluble in aliphatic and aromatic solvents.^[1] It has been used for the deoxygenation of sulfoxides, reductive coupling of aromatic aldehydes and reduction of aldehydes.

Structure and synthesis

Cp₂Ti(CO)₂ is prepared by the reduction of titanocene dichloride with magnesium as a slurry in THT under an atmosphere of carbon monoxide.^[2]

(C₅H₅)₂TiCl₂ + Mg + 2 CO → (C₅H₅)₂Ti(CO)₂ + MgCl₂Both Cp₂Ti(CO)₂ and Cp₂TiCl₂ are tetrahedral as are related zirconium and hafnium compounds. Of historical interest, the complex was first prepared by the reduction of titanocene dichloride with sodium cyclopentadienyl under an atmosphere of carbon monoxide.^[3]

Its structure has been confirmed by X-ray crystallography.^[4]

Notes and References

Book: Sikora . D. J. . Moriarty . K. J. . Rausch . M. D. . Dicarbonylbis(η ⁵ -Cyclopentadienyl) Complexes of Titanium, Zirconium, and Hafnium . 1990 . Inorganic Syntheses . 28 . 250–251 . 10.1002/9780470132593.ch64 . 978-0-471-52619-3 .
Encyclopedia: 2001 . Dicarbonylbis(cyclopentadienyl)titanium . . John Wiley & Sons, Ltd . 10.1002/047084289X.rd073. Snead . Thomas E. . 0-471-93623-5 .
10.1021/ja01512a062. A Metal Carbonyl Compound of Titanium. 1959. Murray. James G.. Journal of the American Chemical Society. 81. 3. 752–753.
10.1016/S0022-328X(00)86431-1. Crystal and Molecular Structure of Titanocene Dicarbonyl, (η⁵-C₅H₅)₂Ti(CO)₂. 1975. Atwood. Jerry L.. Stone. Karen E.. Alt. Helmut G.. Hrncir. Duane C.. Rausch. Marvin D.. Journal of Organometallic Chemistry. 96. C4–C6.