1 research outputs found
Single-Molecule Conductance Behavior of Molecular Bundles
Controlling the orientation of complex molecules in molecular
junctions
is crucial to their development into functional devices. To date,
this has been achieved through the use of multipodal compounds (i.e.,
containing more than two anchoring groups), resulting in the formation
of tri/tetrapodal compounds. While such compounds have greatly improved
orientation control, this comes at the cost of lower surface coverage.
In this study, we examine an alternative approach for generating multimodal
compounds by binding multiple independent molecular wires together
through metal coordination to form a molecular bundle. This was achieved
by coordinating iron(II) and cobalt(II) to 5,5′-bis(methylthio)-2,2′-bipyridine
(L1) and (methylenebis(4,1-phenylene))bis(1-(5-(methylthio)pyridin-2-yl)methanimine)
(L2) to give two monometallic
complexes, Fe-1 and Co-1, and two bimetallic
helicates, Fe-2 and Co-2. Using XPS, all
of the complexes were shown to bind to a gold surface in a fac fashion through three thiomethyl groups. Using single-molecule
conductance and DFT calculations, each of the ligands was shown to
conduct as an independent wire with no impact from the rest of the
complex. These results suggest that this is a useful approach for
controlling the geometry of junction formation without altering the
conductance behavior of the individual molecular wires