Abstract
Graphene nanostructures with π magnetism offer a chemically tunable platform to explore quantum magnetic interactions. However, the realization of nanographene-based chains bearing controlled spin order is highly challenging due to the limited availability of building blocks and the lack of efficient polymerization strategies for chain growth. Here, we demonstrate the successful on-surface synthesis of spin-1/2 antiferromagnetic Heisenberg chains with parity-dependent magnetization based on antiaromatic diaza-hexa-peri-hexabenzocoronene (diaza-HBC) units. Using distinct synthetic strategies, two types of spin chain with different terminals are synthesized, both exhibiting a robust odd–even effect on the spin coupling along the chain. Combined investigations using scanning tunnelling microscopy, non-contact atomic force microscopy, density functional theory calculations and quantum spin models confirm the structures of the diaza-HBC chains and elucidate their magnetic properties, which have an S = 1/2 spin per unit through electron donation from the diaza-HBC core to the Au(111) substrate. Gapped excitations are observed in even-numbered chains, while enhanced Kondo resonance emerges in odd-numbered units of odd-numbered chains due to the redistribution of the unpaired spin along the chain. Our findings provide an effective strategy to construct inaccessible nanographene-based spin chains and unveil the odd–even effect in their magnetic properties, offering potential applications in nanoscale spintronics.
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Data availability
The authors declare that the data supporting the findings of this study are available within the paper and its Supplementary Information files. The data that support the findings of this study are also available from the corresponding authors upon request.
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Acknowledgements
We thank Z. Wang (Boston College) and F. Liu (University of Utah) for the helpful discussions. L.H. and J.M. acknowledge the financial support from the National Natural Science Foundation of China (grant no. 92463307); H.-J.G. acknowledges the financial support from the National Natural Science Foundation of China (grant no. 62488201); H.-J.G., L.H. and H.C. acknowledge the Innovation Program of Quantum Science and Technology (grant no. 2021ZD0302700); S.D. acknowledges the National Key Research and Development Program of China (grant no. 2022YFA1204100); X. Feng and J.M. acknowledge the EU Graphene Flagship (Graphene Core 3, grant no. 881603), the Center for Advancing Electronics Dresden (cfaed), H2020-EU.1.2.2.—FET Proactive grant (LIGHT-CAP, grant no. 101017821) and EIC-2022-Pathfinder Open (ATYPIQUAL, grant no. 101099098); J.F.-R. and J.C.G.H. acknowledge the Portuguese Foundation for Science and Technology (FCT) (grant no. PTDC/FIS-MAC/2045/2021), SNF Sinergia (Grant Pimag) and the HE grant no. FUNLAYERS-101079184; J.F.-R. acknowledges funding from Generalitat Valenciana funding Prometeo2021/017 and grant no. MFA/2022/045, and funding from MICIIN-Spain (grant no. PID2019-109539GB-C41); X.L., L.H. and H.C. acknowledge the Chinese Academy of Sciences (CAS) Project for Young Scientists in Basic Research (grant nos. YSBR-003 and YSBR-053); Y.G. acknowledges the financial support from the National Natural Science Foundation of China (grant no. 52350322).
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H.-J.G. and X. Feng supervised the project. L.H., J.M. and. C.-A.P. conceived the experiment. X. Fu, L.H., X.H., H.C., Y.W., Z.C. and X.L. performed STM/AFM experiments with the guidance of H.-J.G. K.L. synthesized and characterized the precursor molecules under the supervision of J.M. and X. Feng. J.C.G.H. performed theoretical calculations supervised by J.F.-R. Y.G. carried out DFT calculations with the guidance of S.D. L.H., J.M., J.F-.R., X. Feng and H.-J.G. wrote the manuscript with inputs from all authors. X. Fu, L.H. and K.L. contributed equally to this work.
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Nature Synthesis thanks Jiong Lu, Shiyong Wang and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Primary Handling Editor: Peter Seavill, in collaboration with the Nature Synthesis team.
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Fu, X., Huang, L., Liu, K. et al. Building spin-1/2 antiferromagnetic Heisenberg chains with diaza-nanographenes. Nat. Synth 4, 684–693 (2025). https://doi.org/10.1038/s44160-025-00743-5
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DOI: https://doi.org/10.1038/s44160-025-00743-5
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