# On-surface synthesis of nonbenzenoid nanographenes through skeletal rearrangement reactions on Au(111)

## TL;DR

Scientists synthesized unique carbon nanostructures on a gold surface using skeletal rearrangement, creating nanographenes with varied properties.

## Contribution

The study demonstrates the on-surface synthesis of closed-shell and open-shell nonbenzenoid nanographenes via skeletal rearrangement.

## Key findings

- Five closed-shell and two open-shell nanographenes were formed on Au(111) through carbon rearrangements.
- Zigzag edges and fused pentagonal rings significantly influence band gap and spin polarization.
- Bond-resolved scanning tunneling microscopy and DFT calculations revealed structural and electronic properties.

## Abstract

Skeletal rearrangement reaction is a class of important chemical reactions to synthesize various constitutional isomers from a given precursor molecule. This approach allows the synthesis of diverse nanographenes incorporating five- and seven-membered rings, thereby tuning their chemical and physical properties. Here, we present formation of five types of closed-shell and two types of open-shell nanographenes on Au(111) via carbon rearrangements of 7-(2,6-dimethylphenyl)-12-[10-(2,6-dimethylphenyl)anthracen-9-yl]tetraphene. The structural, electronic, and magnetic properties of various products composed of pentagonal or pentagonal/heptagonal rings were in-detail investigated with a combination of bond-resolved scanning tunneling microscopy/scanning tunneling spectroscopy at 4.3 K and density functional theory calculations. We found that both zigzag edges and fused pentagonal rings significantly affect the band gap and the spin polarization. This discovery could facilitate the on-surface synthesis of intriguing carbon nanostructures through skeletal rearrangement.

We present on-surface synthesis of various nonbenzenoid nanographenes, including five closed-shell and two open-shell structures, through skeletal rearrangement reaction using a precursor molecule featuring an out-of-plane benzene ring.