Geometries and binding energies of complexes of cations with benzene (BEN), ferrocene (FC) and (1,1')(3,3')[3,3]ferrocenophane (FCP) have been computed and compared using high level abinitio and DFT calculations. Ferrocene and (l,l')(3,3')[3,3]ferrocenophane are stable compounds that can be used as new binding units for the molecular recognition of cations, since in this Letter we demonstrate that the binding capability toward cations of these compounds using one cyclopentadienyl ring is superior to benzene in similar to 10 kcal/mol. (c) 2006 Elsevier B.V. All rights reserved.