Visually Constructing the Chemical Structure of a Single Molecule by Scanning Raman Picoscopy

TL;DR

This paper introduces scanning Raman picoscopy, a novel ultrahigh-resolution imaging technique that visualizes vibrational modes of single molecules, enabling direct structural determination at the Ångström scale.

Contribution

The paper presents a new methodology combining interference effects and Raman fingerprint databases to visually construct molecular structures from vibrational images.

Findings

Achieved Ångström-level Raman imaging of individual vibrational modes.

Demonstrated visual assembly of a single molecule's chemical structure.

Proposed a Lego-like process for molecular structural determination.

Abstract

The strong spatial confinement of a nanocavity plasmonic field has made it possible to visualize the inner structure of a single molecule and even to distinguish its vibrational modes in real space. With such ever-improved spatial resolution, it is anticipated that full vibrational imaging of a molecule could be achieved to reveal molecular structural details. Here we demonstrate full Raman images of individual vibrational modes on the {\AA}ngstr\"om level for a single Mg-porphine molecule, revealing distinct characteristics of each vibrational mode in real space. Furthermore, by exploiting the underlying interference effect and Raman fingerprint database, we propose a new methodology for structural determination, coined as scanning Raman picoscopy, to show how such ultrahigh-resolution spectromicroscopic vibrational images can be used to visually assemble the chemical structure of a single molecule through a simple Lego-like building process.