On-surface synthesis of chlorinated narrow graphene nanoribbon organometallic hybrids

Graphene nanoribbons (GNRs) and their derivatives attract growing attention due to their excellent electronic and magnetic properties as well as the fine-tuning of such properties that can be obtained by heteroatom substitution and/or edge morphology modification. Here, we introduce graphene nanoribbon derivatives—organometallic hybrids with gold atoms incorporated between the carbon skeleton and side Cl atoms. We show that narrow chlorinated 5-AGNROHs (armchair graphene nanoribbon organometallic hybrids) can be fabricated by on-surface polymerization with omission of the cyclodehydrogenation reaction by a proper choice of tailored molecular precursors. Finally, we describe a route to exchange chlorine atoms connected through gold atoms to the carbon skeleton by hydrogen atom treatment. This is achieved directly on the surface, resulting in perfect unsubstituted hydrogen-terminated GNRs. This will be beneficial in the molecule on-surface processing when the preparation of final unsubstituted hydrocarbon structure is desired.
This work was supported by the National Science Center, Poland (2019/35/B/ST5/02666), and the EU Project PAMS (610446). A.G.L., D.S.P., and P.B. acknowledge the Spanish Agencia Estatal de Investigación (Grants MAT2016-78293-C6-4-R, PID2019-107338RB-C66, and FIS2017-83780-P), Dep. Educación of the Basque Government and UPV/EHU (Grant IT-756-13), and the European Union (EU) through Horizon 2020 (FET-Open project SPRING Grant 863098) for support.