Highly 13C isotope enriched azafullerene, C59N, for nuclear spin labelling

TL;DR

This paper reports the synthesis of highly $^{13}$C isotope enriched azafullerene C$_{59}$N embedded in C$_{60}$, demonstrating homogeneous isotope distribution and potential applications in biological labeling and quantum computing.

Contribution

It introduces a method to produce highly $^{13}$C enriched azafullerene C$_{59}$N with homogeneous isotope distribution and characterizes its properties for potential scientific applications.

Findings

Homogeneous $^{13}$C distribution confirmed by Raman spectroscopy.

ESR measurements show similar concentration levels as non-enriched fullerenes.

Accurate simulation of ESR spectrum with known hyperfine coupling constants.

Abstract

Synthesis of highly $^{13}$C isotope enriched azafullerene, C$_{59}$N embedded in C$_{60}$ is reported. $^{13}$C enriched fullerenes, produced with the Kr\"{a}tschmer-Huffmann process, were subject to a N$_{2}$ discharge that produces C$_{59}$N with a low probability. Raman spectroscopy indicates a homogeneous $^{13}$C distribution. Electron spin resonance measurement (ESR) proves that the C$_{59}$N concentration, 0.2 %, is similar as in non-enriched fullerenes. The ESR spectrum is simulated accurately with the known $^{14}$N and $^{13}$C hyperfine coupling constants. The material enables the nuclear spin-labelling of heterofullerene complexes with a potential for biological applications. It might also find applications as a building element for quantum computation.