Metallophilicity Enhances Electron Transport through Parallel Organometallic 1D Chain Junctions Formed In Situ

TL;DR

This study demonstrates that aurophilic interactions in gold cyanide molecular wires significantly influence their electron transport properties, with parallel arrangements enhancing conductance due to metallophilic coupling.

Contribution

It uncovers the role of metallophilicity in modulating electron transport in in situ assembled 1D gold cyanide chains, highlighting the impact of chain arrangement.

Findings

Parallel chains exhibit higher conductance than series chains.

Aurophilic interactions reorder electronic states, enhancing conductance.

Conductance decays exponentially in series configurations due to quantum interference.

Abstract

We reveal the role of aurophilic interactions in the formation and conductance of gold cyanide molecular wires of variable length-to-width ratios assembled at the tip of an STM break junction in ambient conditions. Specifically, we identify electron transport signatures through 1D single chains containing variable number of monomeric repeats of gold cyanide AuCN, linked in series (AuCN)n, and through adjacent molecular wires linked in parallel. When bound in series, destructive quantum interference causes an exponential decay of conductance in (AuCN)n 1D wires for n=1-3. But when bound in parallel, aurophilic coupling through the gold atoms of neighboring chains reorders electronic states and results in significant enhancement of conductance. Our work reveals that metallophilicity can play a significant role in junction assembly and electron transport characteristics.