1 research outputs found
MoleculeâElectrode Interfaces Controlled by Bulky LongâLegged Ligands in Organometallic Molecular Wires
Abstract Precise control of moleculeâelectrode interface is essential for molecular devices. Herein, new ruthenium acetylide molecular wires with longâlegged phosphine ligands to form a sterically controlled moleculeâelectrode interface are designed. The sharpened Raman signals ascribed to acetylene stretching are observed for the selfâassembled monolayers (SAMs) of the molecular wires with the biphenylâ (2Au) and tertâbutylbiphenylâsubstituted longâlegged dppeâtype ligands (3Au), suggesting that steric hindrance causes formation of uniform SAMs. Scanning tunneling microscope breakâjunction (STMâBJ) study of 3Au reveals narrow conductance features compared with those of 1Au bearing the parent dppe ligands, indicating formation of a uniform molecular junction. Furthermore, the effective electronic interactions between the molecule and electrodes are unique to the longâlegged derivatives, as revealed by the surfaceâenhanced Raman scattering study. Thus, the bulky longâlegged strategy turns out to provide a design concept for a wellâdefined moleculeâelectrode interface