Nature of well-defined conductance of amine anchored molecular junctions

Abstract

Amine terminated molecules show well behaved conductance in the scanning tunneling microscope break-junction experimental measurements. We performed density functional theory based electron transport calculations to explain the nature of this phenomenon. We find that amines can be adsorbed only on apex Au atom, while thiolate group can be attached equally well to undercoordinated and clean Au surfaces. Our calculations show that only one adsorption geo metry is sterically and energetically possible for amine anchored junction whereas three different adsorption geometries with very distinct transport pro perties are almost equally probable for thiolate anchored junction. We calculated the conductance as a function of the junction stretching when the molecules are pulled by the scanning tunneling microscope tip from the Au electrode. Our calculations show that the stretching of the thiolate anchored junction during its formation is accompanied by significant electrode geometry distortio n. The amine anchored junctions exhibit very different behavior -- the electrode remains intact when the scan ning tunneling microscope tip stretches the junction.

References in corpus (14)

• The SIESTA method for ab initio order-N materials simulation
• Efficient index handling of multidimensional periodic boundary conditions
• Density functional method for nonequilibrium electron transport
• Quantum properties of atomic-sized conductors
• Dependence of Single Molecule Junction Conductance on Molecular Conformation
• Single-Molecule Circuits with Well-Defined Molecular Conductance
• Microscopic study of electrical transport through individual molecules with metallic contacts: I. "Band" lineup, voltage drop and high-field transport
• Probability of anomalously large Bit-Error-Rate in long haul optical transmission
• Microscopic study of electrical transport through individual molecules with metallic contacts: II. Effect of the interface structure
• Contact Atomic Structure and Electron Transport Through Molecules
• Fermi level alignment in molecular nanojunctions and its relation to charge transfer
• Do methanethiol adsorbates on the Au(111) surface dissociate?
• Orbital Interaction Mechanisms of Conductance Enhancement and Rectification by Dithiocarboxylate Anchoring Group
• First principle calculations of conductance within plane wave basis set via nonorthogonal Wannier-type atomic orbitals

Cited by in corpus (14)

• Advances and challenges in single-molecule electron transport
• Simultaneous Determination of Conductance and Thermopower of Single Molecule Junctions
• Amine-Linked Single Molecule Circuits: Systematic Trends Across Molecular Families
• Lithographic mechanical break junctions for single-molecule measurements in vacuum: possibilities and limitations
• Super-fermion representation of the Lindblad master equation for the electron transport problem
• Heat dissipation and its relation to thermopower in single-molecule junctions
• Conduction mechanisms in biphenyl-dithiol single-molecule junctions
• Nonequilibrium Fock space for the electron transport problem
• Conductance of a Conjugated Molecule with Carbon Nanotube Contacts
• Mechanism of the enhanced conductance of a molecular junction under tensile stress
• First-principles scheme for spectral adjustment in nanoscale transport
• A real-space method for highly parallelizable electronic transport calculations
• Modeling Single Molecule Junction Mechanics as a Probe of Interface Bonding
• Electron transport through dipyrimidinyl-diphenyl diblock molecular wire: protonation effect