Conformation-Controlled Electron Transport in Single-Molecule Junctions Containing Oligo(phenylene ethynylene) Derivatives

摘要: Understanding the relationships between molecular structure and electronic transport characteristics of single-molecule junctions is fundamental technological importance for future electronics. Herein, we report a combined experimental theoretical study on conductance series oligo(phenylene ethynylene) (OPE) wires, which consist two phenyl-ethynyl-phenyl π units with different dihedral angles. The was studied by scanning tunneling microscopy (STM)-based break-junction techniques under conditions, including variable temperature bias potential, suggested that coherent mechanism takes place in OPE wires length 2.5 nm. are strongly affected coupling strength systems, can be tuned controlling their intramolecular conformation. A cos(2)θ dependence revealed angles conjugated units. Theoretical investigations basis density functional theory nonequilibrium Green's functions (NEGF) gave consistent results observations provided insights into conformation-dominated conductance.