Monodisperse N-Doped Graphene Nanoribbons Reaching 7.7 Nanometers in Length

Abstract

The properties of graphene nanoribbons are highly dependent on structural variables such as width, length, edge structure, and heteroatom doping. Therefore, atomic precision over all these variables is necessary for establishing their fundamental properties and exploring their potential applications. An iterative approach is presented that assembles a small and carefully designed molecular building block into monodisperse N-doped graphene nanoribbons with different lengths. To showcase this approach, the synthesis and characterisation of a series of nanoribbons constituted of 10, 20 and 30 conjugated linearly-fused rings (2.9, 5.3, and 7.7 nm in length, respectively) is presented.

Keywords: graphene; nanoribbons; polycyclic aromatic hydrocarbons.

Scheme 1

Iterative synthesis of NR‐10, NR‐20, and NR‐30.

Figure 1

NMR spectra of NR‐10, NR‐20, and NR‐30 in CDCl₃. The assignments correspond to the lettering in Scheme 1. The stars indicate residual solvent peaks.

Figure 2

a) UV/Vis electronic absorption and b) photoluminescence spectra in CHCl₃. c) Cyclic voltammograms in an Ar‐saturated 0.1 m solution of nBu₄NPF₆ in ODCB. Potentials versus Fc/Fc⁺. d) TRMC (λ _ex=355 nm, I ₀=9.1×10¹⁵ photons cm⁻²).