Chromium hexacarbonyl

As described in a 2023 survey of methods "most cost-effective routes for the synthesis of group 6 hexacarbonyls are based on the reduction of the metal chlorides (CrCl3, MoCl5 or WCl6) with magnesium, zinc or aluminium powders... under CO pressures".

[3] Early work on methods included contributions from luminaries such as Walter Hieber, his student Ernst Otto Fischer, and Giulio Natta.

Using specially produced chromium metal will react with CO gas to give Cr(CO)6 directly, although the method is not used commercially.

[4][5][6] On one hand, there has been continuous efforts to calculate the electronic structures (including HOMO and LUMO) as well as its molecular geometry on the chromium hexacarbonyl compound with various approaches.

Alkyl and aryl organolithium reagents (RLi) add to Cr(CO)6 to give anionic acyl complexes.

[17] In reactions, potassium perrhenate (KReO4) is reduced and carbonylated by the chromium reagents and undergoes [C5H5]− ligand-transfer to afford Re(CO)3(C5H5) complex derivatives.

NFPA 704 four-colored diamond Health 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroform Flammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oil Instability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogen Special hazards (white): no code
Orbital interactions in a chromium-CO complex. On the left, a filled sigma-orbital on CO overlaps with an empty d-orbital on the metal. On the right, an empty pi-antibonding orbital on CO overlaps with a filled d-orbital on the metal.