[2-(N,N-Dimethylaminomethyl)ferrocenyl] as a ligand towards mercury

The diorganomercurial bis[2-(N,N-dimethylaminomethyl)ferrocenyl]mercury(II), (FcN)2Hg (3), can be obtained by the symmetrisation of the heteroleptic (FcN)HgCl (2) with Na2S2O3 or in the transmetallation reaction of 2 with (FcN)Li. By crystallisation only the crystals of rac-(FcN)2Hg were obtained. X-ray diffraction analysis revealed linear coordinated mercury atom with two η1-bonded FcN ligands. Additionally, weak chelate interactions exist between mercury and nitrogen atoms of the CH2NMe2 side chains. According to the 1H-NMR findings, these interactions are not preserved in solution. Diorganomercurial 3 appears in solution as a mixture of two diastereomers with rac/meso-(FcN)2Hg ratio of 1:1. This diastereomeric ratio in solution remains constant within a wide temperature range and in different solvents. The NMR spectroscopic data of the heteroleptic organomercurials [(FcN)HgCl]2·H2O (1) and (FcN)HgCl (2) indicate the chelate-free structure of this compounds in solution within the studied temperature interval (−80 to 90 °C).