In-architecture X-ray assisted C-Br dissociation for on-surface fabrication of diamondoid chains

TL;DR

This paper demonstrates a novel in-architecture X-ray technique to selectively debrominate self-assembled dibromodiamantanes on gold, enabling the creation of diamondoid chains for advanced nanomaterial fabrication.

Contribution

It introduces a new X-ray assisted method for in-situ debromination of diamondoids, facilitating the formation of diamondoid chains on surfaces.

Findings

Debromination occurs at atomic wavelengths and low temperatures.

Self-assembled layers retain their arrangement after debromination.

Diamondoid chains are fabricated in proximity, inaccessible by annealing.

Abstract

The fabrication of well-defined, low-dimensional diamondoid-based materials is a promising approach for tailoring diamond properties such as superconductivity. On-surface self-assembly of halogenated diamondoids under ultrahigh vacuum conditions represents an effective strategy in this direction, enabling reactivity exploration and on-surface synthesis approaches. Here we demonstrate through scanning probe microscopy, time-of-flight mass spectrometry and photoelectron spectroscopy, that self-assembled layers of dibromodiamantanes on gold can be debrominated at atomic wavelengths (Al K$\alpha$ at 8.87 $\mathring{A}$ and Mg K$\alpha$ at 9.89 $\mathring{A}$) and low temperatures without affecting their well-defined arrangement. The resulting 'in-architecture' debromination enables the fabrication of diamantane chains from self-assembled precursors in close proximity, which is otherwise inaccessible through annealing on metal surfaces. Our work introduces a novel approach for the fabrication of nanodiamond chains, with significant implications for in-architecture and layer-by-layer synthesis.