An unusual reaction of A π-complexed lithio-arene: the characterization and structure of μ-(2,2'-difluoro-5,5'-dimethylbenzophenone)bis(tricarbonylchromium(0))

(π-Lithioarene)tricarbonychromium(0) complexes are suggested to be in equilibrium with carbene-bridged dimers at low temperature; the dimers can be trapped with acid chlorides or chloroformate esters yielding bis[(arene)tricarbonylchromium(0)]-carbinols or -ketones, respectively. Thus, the lithiation of (p-fluorotoluene)tricarbonylchromium(0) followed by addition of methyl chloroformate yields …