Molecular Junctions Inspired by Nature: Electrical Conduction through Noncovalent Nanobelts

Area of Science:

• Molecular electronics
• Materials science
• Supramolecular chemistry

Background:

• Charge transport is crucial in biomolecular systems but poorly understood in molecular junctions.
• Translating biomolecular charge transport principles to synthetic devices remains a challenge.

Purpose of the Study:

• To design and investigate electrical properties of novel noncovalent nanobelt (NCN) junctions.
• To explore the effect of hydrogen bonding patterns on charge transport in NCN dimers.

Main Methods:

• Density functional theory (DFT) calculations, including frontier molecular orbitals (FMOs) and projected density of states (DOS).
• Non-equilibrium Green's functions (NEGF-DFT) to study conductance properties.
• Analysis of binding energies for self-assembly potential.

Main Results:

• NCN dimer junctions exhibited metallic-like behavior with low HOMO-LUMO gaps and states at the Fermi level.
• Conductance decreased with cooperative hydrogen bonding, with uniform distribution yielding the highest conductance (51.3 × 10^-6 S).
• Seebeck coefficients indicated n-type behavior for higher conductors and p-type for lower conductors.

Conclusions:

• Hydrogen bonding significantly influences charge transport in NCN junctions.
• NCNs show potential for forming self-assembled monolayer (SAM) heterojunctions for long-range charge transport.
• The study provides insights into designing molecular electronic devices based on noncovalent interactions.