Abstract
Metallocene research has influenced the development of organometallic chemistry, and the metal–nonmetal inverted half-sandwich structure (inverse metallocene) was very recently discovered. However, additional instances are required to propose the concept inverse metallocene and it remains uncertain whether metal five-membered ring structures analogous to the cyclopentadienyl anion structure exist. Herein we report the synthesis of a series of palladium analogs Pd8(PPh)2(PPh3)2(Ph2P=O)(S-Adm)5 (Pd8–P), Pd6(PPh)(PPh3)(S-Adm)6 (Pd6), Pd5(PPh)(S-Adm)4[(Ph2P)2O] (Pd5–O), and Pd5(PPh)(S-Adm)4[(Ph2P)2CH2] (Pd5–C), identify their fundamental metal building block named five-membered Pd aromatic ring, and reveal their conjugation‒photothermy cor…
Abstract
Metallocene research has influenced the development of organometallic chemistry, and the metal–nonmetal inverted half-sandwich structure (inverse metallocene) was very recently discovered. However, additional instances are required to propose the concept inverse metallocene and it remains uncertain whether metal five-membered ring structures analogous to the cyclopentadienyl anion structure exist. Herein we report the synthesis of a series of palladium analogs Pd8(PPh)2(PPh3)2(Ph2P=O)(S-Adm)5 (Pd8–P), Pd6(PPh)(PPh3)(S-Adm)6 (Pd6), Pd5(PPh)(S-Adm)4[(Ph2P)2O] (Pd5–O), and Pd5(PPh)(S-Adm)4[(Ph2P)2CH2] (Pd5–C), identify their fundamental metal building block named five-membered Pd aromatic ring, and reveal their conjugation‒photothermy correlation. In particular, we report an average NIR-II photothermal conversion efficiency per metal atom of 14.7% and the stability of the five-membered Pd aromatic ring, as illustrated by the fact that Pd5–C maintained photothermy performance for >10 heating–cooling cycles even after the ligands were removed. We further demonstrate the great potential of inverse palladocenes in areas such as laser shielding, high-temperature degradation, ignition, and temperature/light control. These results declare the research and application start of a type of materials named inverse palladocenes.
Data availability
The X-ray crystallographic coordinates for structures reported in this study have been deposited at the Cambridge Crystallographic Data Center (CCDC), under deposition numbers 2500802 for Pd5–C, 2500805 for Pd5–O, 2500806 for Pd6, 2500807 for Pd8–P, and 2500808 for (Ph2P=O)2, respectively. These data can be obtained free of charge from the CCDC via www.ccdc.cam.ac.uk/data_request/cif. Checkcif file for Pd5–C, Pd5–O, Pd6, Pd8–P, and (Ph2P=O)2 CIF files and Supplementary Movie 1 are given as Supplementary Dataset. All data supporting the findings of this study are available within the article and its Supplementary Information files. All data are available from the corresponding author upon request. Source data are provided with this paper.
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Acknowledgements
This work was supported by the National Natural Science Foundation of China (Nos. 22471275, 22403096, 21925303, 21829501, 22033005, 22171267, 21771186, 21222301, 21171170 and 21528303), to Q.Y., J.L., and Z.W., the National Key Research and Development Program of China (No. 2022YFA1503900), the Guangdong Provincial Key Laboratory of Catalysis (No. 2020B121201002), the NSFC Center for Single-Atom Catalysis (22388102) to J.L., and the Anhui Provincial Natural Science Foundation 2408085QB040 to Q.Y. Computational resources were supported by the Center for Computational Science and Engineering at Southern University of Science and Technology and the CHEM high-performance supercomputer cluster (CHEM-HPC) located at department of chemistry, SUSTech.
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Author notes
These authors contributed equally: Qing You, Xue-Lian Jiang, Yan Zhao.
Authors and Affiliations
Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, CAS Center for Excellence in Nanoscience, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, PR China
Qing You, Wanmiao Gu & Zhikun Wu 1.
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, PR China
Xue-Lian Jiang & Jun Li 1.
Institute of Physical Science and Information Technology, Anhui University, Hefei, Anhui, PR China
Yan Zhao & Zhikun Wu 1.
Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing, PR China
Jun Li 1.
Fundamental Science Center of Rare Earths, Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou, PR China
Jun Li 1.
Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, PR China
Zhikun Wu
Authors
- Qing You
- Xue-Lian Jiang
- Yan Zhao
- Wanmiao Gu
- Jun Li
- Zhikun Wu
Contributions
Z.W and J.L. conceived the initial idea and managed the overall project. Q.Y. designed and performed the experiments. X.-L.J. performed the theoretical calculations and conducted the bonding analysis under the supervision of J.L. Q.Y. performed the electronic transition analyses using TD-DFT calculations. Y.Z. collected and analyzed the XPS, DPV, SEM, and TEM. data with the assistance of W.G., Q.Y., and Z.W. wrote the paper with the assistance of X.-L.J. and J.L.
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Correspondence to Jun Li or Zhikun Wu.
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You, Q., Jiang, XL., Zhao, Y. et al. Inverse palladocenes. Nat Commun (2026). https://doi.org/10.1038/s41467-026-68955-7
Received: 22 May 2025
Accepted: 15 January 2026
Published: 30 January 2026
DOI: https://doi.org/10.1038/s41467-026-68955-7