Stability And Destabilization Processes In The Formation Of Ferrocene-Based Metal-Organic Molecule-Metal Nano-Junctions

The realization of functional metal-molecule junctions relies on our understanding and control of the fundamental interactions leading to or preventing the formation of nanojunctions. In this work, focusing on the promising double-decker organometallic compound ferrocene, deposited on a Cu(111) surface, we show that destabilization or dissociation of these compounds can occur depending on the nature of the metal atom deposited on the ferrocene. Specifically, at variance with the more common deposition of Cu atoms, Fe atoms can give rise to a disassembly of the Fe(C5H5)(2) structure in a barrierless way, potentially realizing catalytic active sites. Conversely, the deposition of Co can occur only upon overcoming an activation barrier of about 0.85 eV. In this case, the ferrocene does not dissociate, but the Co atom results fully inserted in the upper C5H5 ring of the organometallic molecule, thus becoming a new six-member structure that eventually allows for a selective extraction of deposited ferrocene molecules.