Single-Molecule Junction Conductance through Diaminoacenes

TL;DR

This paper investigates how the conductance of single-molecule diaminoacenes depends on molecular structure, including fused aromatic rings and amino group positions, providing new experimental insights into molecular electronics.

Contribution

It presents experimental data on electron transport through diaminoacenes, highlighting the influence of aromatic ring fusion and amino group placement on conductance, which was previously underexplored.

Findings

Conductance varies with the number of fused aromatic rings.

Amino group position affects electron transport.

Maximum conductance occurs with minimal aromaticity disruption.

Abstract

The study of electron transport through single molecules is essential to the development of molecular electronics. Indeed, trends in electronic conductance through organic nanowires have emerged with the increasing reliability of electron transport measurements at the single-molecule level. Experimental and theoretical work has shown that tunneling distance, HOMO-LUMO gap and molecular conformation influence electron transport in both saturated and pi-conjugated nanowires. However, there is relatively little experimental data on electron transport through fused aromatic rings. Here we show using diaminoacenes that conductivity depends not only on the number of fused aromatic rings in the molecule, which defines the molecular HOMO-LUMO gap, but also on the position of the amino groups on the rings. Specifically, we find that conductance is highest with minimal disruption of aromaticity in fused aromatic nanowires.