A series of heterometallic complexes of general formula [C][M7M’F7(RCO2)16]
have been synthesized and characterized. M and M’ are generally Cr(III),
V(III) and Co(II). The cation C is generally a dialkylammonium group and the
carboxylate is pivalate. The single-crystal X-ray structure of each complex
shows the eight-membered wheel, with a cation sitting in the cavity. The proton
NMR of these complexes has been studied, confirming the existence of the
heterometallic octanuclear wheel in solution, thus confirming the X-ray structure.
Additionally, the proton NMR of these complexes shows the close proximity of
the cation to the metal centers, proving that the solid state structure is kept in
solution. Cation exchange experiments have been performed and will also be
discussed in the presentation.