Ferrocenyl(dimethyl)aluminum dimer [(η5-C5H5)Fe(η5-C5H4)AlMe2]2

The reaction of ferrocenyllithium (FcLi, 1) with dimethyl or diethylaluminum chloride affords known mixed dimers 2 built from dialkyl(ferrocenyl))aluminium and dialkylaluminum chloride and also, depending on the reaction conditions, the unknown dimers from dialkyl(ferrocenyl)aluminum 3, of which the dimethyl derivative could be isolated in a pure state and characterised by X-ray structural analysis. The ferrocenyl group occupies the bridging position and there is a centre of inversion. The solution-state structures were determined by NMR spectroscopic methods (1H, 13C, 27Al NMR). The gas-phase structure of monomer FcAlH23(M) was optimised at the B3LYP/6-311 + G(d,p) level of theory.

Graphical abstractThe dimer of dimethyl(ferrocenyl))aluminum was prepared and fully characterised in solution and in the solid state for the first time. This dimer contains the ferrocenyl group in a fairly unsymmetrical bridging position: Al(1)–C(1) = 204.6(5) and Al(1)–C(1A) = 226.9(4) pm).Figure optionsDownload full-size imageDownload as PowerPoint slide