Unraveling the Interplay between Quantum Transport and Geometrical Conformations in Monocyclic Hydrocarbons Molecular Junctions

TL;DR

This study investigates how the geometrical conformations of monocyclic hydrocarbons influence quantum transport in molecular junctions, combining simulations, DFT calculations, and experiments to better understand molecular electronics.

Contribution

It introduces a new criterion for determining molecular orientation in monocyclic hydrocarbons and links conformation to transport properties in molecular junctions.

Findings

Identified molecular orientations of benzene, toluene, and cyclohexane on gold contacts.

Established correlation between molecular conformation and electronic transport.

Enhanced understanding of molecular electronics with complex cyclic hydrocarbons.

Abstract

In the field of molecular electronics, particularly in quantum transport studies, the orientation of molecules plays a crucial role. This orientation, with respect to the electrodes, can be defined through the cavity of ring-shaped monocyclic hydrocarbon molecules. In this manuscript, we unveil the geometrical conformation of these molecules when they are trapped between two atomically sharp electrodes through a combination of dynamic simulations, electronic transport calculations based on density functional theory, and break junction experiments under room conditions. Moreover, we present a novel criterion for determining the molecular orientation of benzene, toluene, (aromatic) and cyclohexane (aliphatic) solvents. Our findings for the identification of the molecular orientations on gold metal nanocontacts and their associated transport properties, can improve the understanding of molecular electronics using more complex cyclic hydrocarbons.