Structural Studies and Solution Dynamics of Complexes of Magnesium with theN,N-Dimethylaminomethylferrocenyl Ligand

Abstract

The reaction of {C,N-[Fe(η5-C5H5)(η5-C5H3(CH2NMe2)-2)]}Li, (FcN)Li, with magnesium bromide affords the magnesate complex Li2Mg(FcN)2Br2(OEt2)2 (1). Extraction of 1 with diethyl ether yields (FcN)2Mg(OEt2) (2). The reaction of (FcN)Li with magnesium halides and THF directly affords (FcN)2Mg(THF) (3). In solution, these compounds appear as a mixture of diastereomers, whereas in the solid state they each crystallize as a single rac-diastereomer. The ratio of rac-meso-diastereomers in solution is solvent- and temperature-dependent, consistent with an intermolecular exchange between the diastereomers. An intramolecular dynamic phenomenon involving dissociation and recoordination of Mg−N bonds was also observed.