Light Up a Nanocluster

Abstract

Atomically precise metal nanoclusters (MNCs) have emerged as tailorable luminescent materials with visible to near-infrared emission modulated by core (kernel) size, metal composition, and ligand engineering. These ultrasmall clusters exhibit discrete quantum-confined electronic states with strong spin–orbit coupling (SOC), enabling diverse emission pathways. Current research focuses on elucidating emission mechanisms and developing strategies to enhance fluorescence quantum yields. In this review, we emphasize structure–photoluminescence (PL) correlations and the underlying excited-state origins of luminescence: (i) coinage-metal clusters display multiple emissive channels—including prompt fluorescence, room-temperature phosphorescence, and TADF; (ii) the electronic gap and thus emission energy is directly governed by core size and metal identity, with core shrinkage and enhanced SOC generally inducing red-shifts; and (iii) ligand shell properties (identity/rigidity/packing) control charge-transfer pathways and nonradiative decay, while heterometal doping or rigidification modulates state ordering to brighten emission without necessarily shifting band positions. Importantly, many clusters exhibit dual-emission behavior. We propose a coupled core–shell emissive-state model in which one band originates from metal-core excitation and the other from a ligand- or motif-centered charge-transfer state. Finally, we outline future challenges: dissecting core versus shell contributions to PL and boosting quantum efficiency through targeted control of cluster composition and ligand shell. Progress on these fronts is crucial for the rational design of next-generation cluster emitters.

Keywords

aggregation-induced emission / coinage-metal nanoclusters / heterometal doping / photoluminescence

References

[1] F. Hu, Z. J. Guan, G. Yang, et al., “Molecular Gold Nanocluster Au156 Showing Metallic Electron Dynamics,” Journal of the American Chemical Society 143 (2021): 17059–17067.

[2] S. H. Li, J. Wei, Q. F. Yao, X. R. Song, J. P. Xie, and H. H. Yang, “Emerging Ultrasmall Luminescent Nanoprobes for in Vivo Bioimaging,” Chemical Society Reviews 52 (2023): 1672–1696.

[3] S. Li, N. N. Li, X. Y. Dong, S. Q. Zang, and T. C. W. Mak, “Chemical Flexibility of Atomically Precise Metal Clusters,” Chemical Reviews 124 (2024): 7262–7378.

[4] Z. Y. Liu, L. S. Luo, and R. C. Jin, “Visible to NIR-II Photoluminescence of Atomically Precise Gold Nanoclusters,” Advanced Materials 36 (2024): 2309073.

[5] Y. Li, M. Zhou, and R. Jin, “Programmable Metal Nanoclusters With Atomic Precision,” Advanced Materials 33 (2021): 2006591.

[6] X. J. Zou, X. Kang, and M. Z. Zhu, “Recent Developments in the Investigation of Driving Forces for Transforming Coinage Metal Nanoclusters,” Chemical Society Reviews 52 (2023): 5892–5967.

[7] Z. C. Zhao, J. Y. Wei, Z. L. Lang, et al., “A Superatomic {Ag8}⁶⁺ Cluster Induced by Asymmetric Mixed-Addendum Polyoxometalate,” Journal of the American Chemical Society 147 (2025): 25107–25114.

[8] M. Z. Chi, J. Y. Wei, Z. C. Zhao, et al., “Structural Isomerism of {Ag14}¹⁰⁺ Nanocluster Encapsulated by Bowl-Like Polyoxometalates,” Angewandte Chemie International Edition 64 (2025): e202424499.

[9] Q. F. Yao, M. Zhu, Z. C. Yang, et al., “Molecule-Like Synthesis of Ligand-protected Metal Nanoclusters,” Nature Reviews Materials 10 (2025): 89–108.

[10] S. Maity, S. Kolay, S. Chakraborty, A. Devi, and A. P. Rashic, “A Comprehensive Review of Atomically Precise Metal Nanoclusters With Emergent Photophysical Properties towards Diverse Applications,” Chemical Society Reviews 54 (2025): 1785–1844.

[11] Y. Q. Feng, M. Y. Zhao, J. X. Yang, et al., “Wearing Gigantic Silver Armor on Transition-Metal-Containing Polyoxometalates: Formation of Supertetrahedral Intercluster Compounds,” Angewandte Chemie International Edition 64 (2025): e202505511.

[12] Y. Q. Feng, F. Y. Fu, L. L. Zeng, et al., “Atomically Precise Silver Clusters Stabilized by Lacunary Polyoxometalates With Photocatalytic CO₂ Reduction Activity,” Angewandte Chemie International Edition 63 (2024): e202317341.

[13] T. K. Chen, H. B. Lin, Y. T. Cao, Q. F. Yao, and J. P. Xie, “Interactions of Metal Nanoclusters With Light: Fundamentals and Applications,” Advanced Materials 34 (2022): 2103918.

[14] S. Hossain, D. Hirayama, A. Ikeda, et al., “Atomically Precise Thiolate-Protected Gold Nanoclusters: Current Status of Designability of the Structure and Physicochemical Properties,” Aggregate 4 (2023): e255.

[15] C. M. Aikens, “Electronic and Geometric Structure, Optical Properties, and Excited State Behavior in Atomically Precise Thiolate-Stabilized Noble Metal Nanoclusters,” Accounts of Chemical Research 51 (2018): 3065–3073.

[16] D. M. Chevrier, V. D. Thanthirige, Z. Luo, et al., “Structure and Formation of Highly Luminescent Protein-stabilized Gold Clusters,” Chemical Science 9 (2018): 2782–2790.

[17] M. Zhou, T. Higaki, Y. W. Li, et al., “Three-Stage Evolution From Nonscalable to Scalable Optical Properties of Thiolate-Protected Gold Nanoclusters,” Journal of the American Chemical Society 141 (2019): 19754–19764.

[18] Z. Han, X. Y. Dong, P. Luo, et al., “Ultrastable Atomically Precise Chiral Silver Clusters With More Than 95% Quantum Efficiency,” Science Advances 6 (2020): eaay0107.

[19] Z. N. Wu, J. L. Liu, Y. Gao, et al., “Assembly-Induced Enhancement of Cu Nanoclusters Luminescence With Mechanochromic Property,” Journal of the American Chemical Society 137 (2015): 12906–12913.

[20] T. T. Li, Z. Y. Wang, Y. Zhang, and Z. N. Wu, “Engineering Coinage Metal Nanoclusters for Electroluminescent Light-Emitting Diodes,” Nanomaterials 12 (2022): 3837.

[21] Z. N. Wu, Q. F. Yao, S. Q. Zang, and J. P. Xie, “Aggregation-induced Emission in Luminescent Metal Nanoclusters,” National Science Review 8 (2020): nwaa208.

[22] S. X. Wang, X. M. Meng, A. Das, et al., “A 200-Fold Quantum Yield Boost in the Photoluminescence of Silver-Doped Ag_XAu_25−X Nanoclusters: The 13th Silver Atom Matters,” Angewandte Chemie International Edition 53 (2014): 2376–2380.

[23] X. Kang, M. Zhou, S. X. Wang, G. D. Sun, M. Z. Zhu, and R. C. Jin, “The Tetrahedral Structure and Luminescence Properties of Bi-metallic Pt1Ag28(SR)18(PPh3)4 Nanocluster,” Chemical Science 8 (2017): 2581–2587.

[24] Z. K. Wu and R. C. Jin, “On the Ligand's Role in the Fluorescence of Gold Nanoclusters,” Nano Letters 10 (2010): 2568–2573.

[25] Y. Z. Wu, J. Kong, W. Zhang, S. X. Wang, and M. Zhou, “Effect of Silver Alloying on the Vibrational Dynamics of Rod-Shaped Gold Nanoclusters,” Journal of Physical Chemistry C 127 (2023): 13723–13730.

[26] N. Goswami, Q. F. Yao, Z. T. Luo, J. G. Li, T. Chen, and J. P. Xie, “Luminescent Metal Nanoclusters With Aggregation-Induced Emission,” Journal of Physical Chemistry Letters 7 (2016): 962–975.

[27] J. S. Xin, J. Xu, C. Zhu, et al., “Restriction of Intramolecular Rotation for Functionalizing Metal Nanoclusters,” Chemical Science 14 (2023): 8474–8482.

[28] T. Chen, S. Yang, J. S. Chai, et al., “Crystallization-induced Emission Enhancement: A Novel Fluorescent Au-Ag Bimetallic Nanocluster With Precise Atomic Structure,” Science Advances 3 (2017): e1700956.

[29] D. Liu, G. Q. Gao, Y. Y. Zhang, et al., “A Dual-site Doping Strategy to Enhance the Sodium Storage Performance of an O3-type Layered Sodium Oxide Cathode,” Chemical Communications 61 (2025): 15258–15261.

[30] C. H. Yao, C. Q. Xu, I. H. Park, et al., “Giant Emission Enhancement of Solid-State Gold Nanoclusters by Surface Engineering,” Angewandte Chemie International Edition 59 (2020): 8270–8276.

[31] J. Mei, N. L. C. Leung, R. T. K. Kwok, J. W. Y. Lam, and B. Z. Tang, “Aggregation-Induced Emission: Together We Shine, United We Soar!,” Chemical Reviews 115 (2015): 11718–11940.

[32] X. Kang, S. X. Wang, and M. Z. Zhu, “Observation of a New Type of Aggregation-induced Emission in Nanoclusters,” Chemical Science 9 (2018): 3062–3068.

[33] S. S. Zhang, L. Feng, R. D. Senanayake, et al., “Diphosphine-protected Ultrasmall Gold Nanoclusters: Opened Icosahedral Au13 and Heart-shaped Au8 Clusters,” Chemical Science 9 (2018): 1251–1258.

[34] H. Chang, N. S. Karan, K. Shin, et al., “Highly Fluorescent Gold Cluster Assembly,” Journal of the American Chemical Society 143 (2020): 326–334.

[35] H. Z. Ma, X. N. Zhang, L. Liu, et al., “Bioactive NIR-II Gold Clusters for Three-dimensional Imaging and Acute Inflammation Inhibition,” Science Advances 9 (2023): eadh7828.

[36] S. E. Crawford, M. J. Hartmann, and J. E. Millstone, “Surface Chemistry-Mediated Near-Infrared Emission of Small Coinage Metal Nanoparticles,” Accounts of Chemical Research 52 (2019): 695–703.

[37] R. C. Jin, C. J. Zeng, M. Zhou, and Y. X. Chen, “Atomically Precise Colloidal Metal Nanoclusters and Nanoparticles: Fundamentals and Opportunities,” Chemical Reviews 116 (2016): 10346–10413.

[38] K. L. D. M. Weerawardene and C. M. Aikens, “Theoretical Insights Into the Origin of Photoluminescence of Au25(SR)18– Nanoparticles,” Journal of the American Chemical Society 138 (2016): 11202–11210.

[39] Q. Li, C. J. Zeman, G. C. Schatz, and X. W. Gu, “Source of Bright Near-Infrared Luminescence in Gold Nanoclusters,” ACS Nano 15 (2021): 16095–16105.

[40] S. Link, A. Beeby, S. FitzGerald, M. A. El-Sayed, T. G. Schaaff, and R. L. Whetten, “Visible to Infrared Luminescence From a 28-Atom Gold Cluster,” Journal of Physical Chemistry B 106 (2002): 3410–3415.

[41] J. P. Xie, Y. G. Zheng, and J. Y. Ying, “Protein-Directed Synthesis of Highly Fluorescent Gold Nanoclusters,” Journal of the American Chemical Society 131 (2009): 888–889.

[42] A. Mathew, E. Varghese, S. Choudhury, S. K. Pal, and T. Pradeep, “Efficient Red Luminescence From Organic-soluble Au25 Clusters by Ligand Structure Modification,” Nanoscale 7 (2015): 14305–14315.

[43] Z. T. Luo, X. Yuan, Y. Yu, et al., “From Aggregation-Induced Emission of Au(I)–Thiolate Complexes to Ultrabright Au(0)@Au(I)–Thiolate Core–Shell Nanoclusters,” Journal of the American Chemical Society 134 (2012): 16662–16670.

[44] O. Koshevoy, Y. C. Chang, A. J. Karttunen, et al., “Intensely Luminescent Homoleptic Alkynyl Decanuclear Gold(I) Clusters and Their Cationic Octanuclear Phosphine Derivatives,” Inorganic Chemistry 51 (2012): 7392–7403.

[45] Y. Yu, Z. T. Luo, D. M. Chevrier, et al., “Identification of a Highly Luminescent Au22(SG)18 Nanocluster,” American Chemical Society 136 (2014): 1246–1249.

[46] K. Pyo, V. D. Thanthirige, K. U. Kwak, P. Pandurangan, G. Ramakrishna, and D. Lee, “Ultrabright Luminescence From Gold Nanoclusters: Rigidifying the Au(I)–Thiolate Shell,” Journal of the American Chemical Society 137 (2015): 8244–8250.

[47] Q. F. Yao, X. Yuan, V. Fung, et al., “Understanding Seed-mediated Growth of Gold Nanoclusters at Molecular Level,” Nature Communications 8 (2017): 927.

[48] M. Zhou, T. Higaki, G. X. Hu, et al., “Three-orders-of-magnitude Variation of Carrier Lifetimes With Crystal Phase of Gold Nanoclusters,” Science 364 (2019): 279–282.

[49] Z. N. Wu, Q. F. Yao, J. H. Chai, et al., “Unraveling the Impact of Gold(I)–Thiolate Motifs on the Aggregation-Induced Emission of Gold Nanoclusters,” Angewandte Chemie International Edition 59 (2020): 9934–9939.

[50] L. S. Luo, Z. Y. Liu, X. S. Du, and R. C. Jin, “Photoluminescence of the Au38(SR)26 Nanocluster Comprises Three Radiative Processes,” Communications Chemistry 6 (2023): 22.

[51] Z. Han, X. L. Zhao, P. Peng, et al., “Intercluster Aurophilicity-driven Aggregation Lighting Circularly Polarized Luminescence of Chiral Gold Clusters,” Nano Research 13 (2020): 3248–3252.

[52] P. Luo, X. J. Zhai, S. Bai, et al., “Highly Efficient Circularly Polarized Luminescence From Chiral Au 13 Clusters Stabilized by Enantiopure Monodentate NHC Ligands,” Angewandte Chemie International Edition 62 (2023): e202219017.

[53] S. M. Zhai, H. Zhang, Y. Wang, et al., “Stimuli-Responsive Circularly Polarized Luminescence of Gold Clusters Based on Hydrogen-Bond Driven Intercluster Coupling,” Angewandte Chemie International Edition 64 (2025): e202502168.

[54] C. Zhang, S. Guan, Z. M. Zhang, B. Y. Wu, Z. Han, and S. Q. Zang, “Maximized Circularly Polarized Luminescence From Metal Clusters Accelerates Chiral Photopolymerization,” Nature Communications 16 (2025): 6848.

[55] J. Zhou, X. F. Yang, P. S. Zheng, et al., “Construction of an Au12Cd2 Nanocluster With Circularly Polarized Luminescence by a Metal- and Ligand-exchange Strategy,” Chemical Science 15 (2024): 4853–4859.

[56] H. Y. Ru, J. K. Yang, Y. N. Yang, et al., “Unprecedented Stacking-dependent Piezoluminescence Enhancement in Atomically Precise Superatomic Gold Nanoclusters,” Science Advances 11 (2025): eadv0298.

[57] Y. N. Yang, Q. Y. Wan, M. J. Zhu, et al., “Pressure-Activated Efficient Near-Infrared Luminescence in Atomically Precise Gold Nanoclusters,” Journal of the American Chemical Society 147 (2025): 26991–26999.

[58] C. Zhang, X. B. Gao, W. R. Chen, et al., “Advances of Gold Nanoclusters for Bioimaging,” Iscience 25 (2022): 105022.

[59] A. Baghdasaryan and H. J. Dai, “Molecular Gold Nanoclusters for Advanced NIR-II Bioimaging and Therapy,” Chemical Reviews 125 (2025): 5195–5227.

[60] Y. Tian, W. J. Zheng, X. Y. Zhang, et al., “Triple Ligand Engineered Gold Nanoclusters With Enhanced Fluorescence and Device Compatibility for Efficient Electroluminescence Light-Emitting Diodes,” Nano Letters 23 (2023): 4423–4430.

[61] Y. C. Chao, K. P. Cheng, C. Y. Lin, et al., “Non-Toxic Gold Nanoclusters for Solution-Processed White Light-Emitting Diodes,” Scientific Reports 8 (2018): 8860.

[62] Y. S. Yang, K. Z. Wang, and D. P. Yan, “Ultralong Persistent Room Temperature Phosphorescence of Metal Coordination Polymers Exhibiting Reversible pH-Responsive Emission,” ACS Applied Materials and Interfaces 8 (2016): 15489–15496.

[63] Y. Yu, J. Y. Fu, G. T. Chang, and R. X. Li, “Progress in the Modulation of Fluorescence Intensity, Lifetime, Polychromaticity, and Stability for Information Encryption and Printing Compatibility,” Journal of Alloys and Compounds 1040 (2025): 183420.

[64] Y. T. Cao, J. H. Guo, R. Shi, et al., “Evolution of Thiolate-stabilized Ag Nanoclusters From Ag-thiolate Cluster Intermediates,” Nature Communications 9 (2018): 2379.

[65] Y. P. Xie, Y. L. Shen, G. X. Duan, J. Han, L. P. Zhang, and X. Lu, “Silver Nanoclusters: Synthesis, Structures and Photoluminescence,” Materials Chemistry Frontiers 4 (2020): 2205–2222.

[66] G. Li, Z. Lei, and Q. M. Wang, “Luminescent Molecular Ag−S Nanocluster [Ag62S13(SBut)32](BF4)4,” Journal of the American Chemical Society 132 (2010): 17678–17679.

[67] A. Desireddy, B. E. Conn, J. S. Guo, et al., “Ultrastable Silver Nanoparticles,” Nature 501 (2013): 399–402.

[68] B. E. Conn, A. Desireddy, A. Atnagulov, et al., “M4Ag44(p-MBA)30 Molecular Nanoparticles,” Journal of Physical Chemistry C 119 (2015): 11238–11249.

[69] S. Jin, S. X. Wang, Y. B. Song, et al., “Crystal Structure and Optical Properties of the [Ag62S12(SBut)32]2+ Nanocluster With a Complete Face-Centered Cubic Kernel,” Journal of the American Chemical Society 136 (2014): 15559–15565.

[70] Y. Niihori, N. Takahashi, and M. Mitsu, “Photophysical and Thermodynamic Properties of Ag29(BDT)12(TPP)X (x = 0–4) Clusters in Secondary Ligand Binding–Dissociation Equilibria Unraveled by Photoluminescence Analysis,” Journal of Physical Chemistry C 124 (2020): 5880–5886.

[71] W. Ishii, Y. Okayasu, Y. Kobayashi, et al., “Excited State Engineering in Ag29 Nanocluster Through Peripheral Modification With Silver(I) Complexes for Bright Near-Infrared Photoluminescence,” Journal of the American Chemical Society 145 (2023): 11236–11244.

[72] D. M. Chevrier, B. E. Conn, B. Li, et al., “Interactions Between Ultrastable Na4Ag44(SR)30 Nanoclusters and Coordinating Solvents: Uncovering the Atomic-Scale Mechanism,” ACS Nano 14 (2020): 8433–8441.

[73] S. B. Wang, W. M. He, Y. J. Cui, Z. Zhou, L. F. Ma, and S. Q. Zang, “Atomically Precise Chiral Silver Clusters Based on Non-chiral Ligands for Acid/Base Stimulated Luminescence Response,” Nanoscale 15 (2023): 12679–12685.

[74] S. S. Zhang, S. Havenridge, C. K. Zhang, et al., “Sulfide Boosting near-Unity Photoluminescence Quantum Yield of Silver Nanocluster,” Journal of the American Chemical Society 144 (2022): 18305–18314.

[75] C. K. Zhang, W. D. Si, Z. Wang, C. H. Tung, and D. Sun, “Chiral Ligand-Concentration Mediating Asymmetric Transformations of Silver Nanoclusters: NIR-II Circularly Polarized Phosphorescence Lighting,” Angewandte Chemie International Edition 63 (2024): e202404545.

[76] A. Hajda, R. Guha, S. M. Copp, and J. Olesiak-Bańska, “Two-photon Brightness of NIR-emitting, Atomically Precise DNA-stabilized Silver Nanoclusters,” Chemical Science 16 (2024): 1737–1745.

[77] V. Rück, N. K. Mishra, K. K. Sørensen, et al., “Bioconjugation of a Near-Infrared DNA-Stabilized Silver Nanocluster to Peptides and Human Insulin by Copper-Free Click Chemistry,” Journal of the American Chemical Society 145 (2023): 16771–16777.

[78] A. K. Das, S. Biswas, S. S. Manna, B. Pathak, and S. Mandal, “An Atomically Precise Silver Nanocluster for Artificial Light-harvesting System Through Supramolecular Functionalization,” Chemical Science 13 (2022): 8355–8364.

[79] A. Sardar, Y. T. Wang, A. Mazumder, et al., “High-Yield Synthesis of Cu29 Nanoclusters and Their Applications in Photothermal Conversion and Catalysis,” Inorganic Chemistry 64 (2025): 17687–17695.

[80] H. Li, H. S. Zhai, C. J. Zhou, et al., “Atomically Precise Copper Cluster With Intensely Near-Infrared Luminescence and Its Mechanism,” Journal of Physical Chemistry Letters 11 (2020): 4891–4896.

[81] M. M. Zhang, X. Y. Dong, Z. Y. Wang, et al., “AIE Triggers the Circularly Polarized Luminescence of Atomically Precise Enantiomeric Copper(I) Alkynyl Clusters,” Angewandte Chemie International Edition 59 (2020): 10052–10058.

[82] S. K. Peng, H. Yang, D. Luo, et al., “Enhancing Photoluminescence Efficiency of Atomically Precise Copper(i) Nanoclusters Through a Solvent-induced Structural Transformation,” Inorganic Chemistry Frontiers 9 (2022): 5327–5334.

[83] H. Li, T. Wang, J. J. Han, et al., “Fluorescence Resonance Energy Transfer in Atomically Precise Metal Nanoclusters by Cocrystallization-induced Spatial Confinement,” Nature Communications 15 (2024): 5351.

[84] X. L. Sun, W. Y. Jiang, P. L. Du, et al., “Atomically Precise Cu12 Nanoclusters With Thermally Activated Delayed Fluorescence Properties,” Inorganic Chemistry 64 (2025): 716–722.

[85] L. J. Liu, M. M. Zhang, Z. Q. Deng, et al., “NIR-II Emissive Anionic Copper Nanoclusters With Intrinsic Photoredox Activity in Single-electron Transfer,” Nature Communications 15 (2024): 4688.

[86] J. J. Fang, Z. Liu, Y. Zhang, Z. Y. Wang, Y. P. Xie, and X. Lu, “Alkynyl Copper(I) Nanoclusters with Thermally Activated Delayed Fluorescence as Efficient Scintillator for X-Ray Imaging,” Science China Chemistry 68 (2025): 4904–4911.

[87] S. J. Zhou, S. S. Zhang, H. P. Li, D. Sun, J. Z. Zhang, and X. Xin, “Solvent-Induced Self-Assembly of Copper Nanoclusters for White Light Emitting Diodes,” ACS Applied Nano Materials 4 (2021): 10911–10920.

[88] Z. Z. Yang, A. L. Yang, W. Ma, et al., “Atom-precise Fluorescent Copper Cluster for Tumor Microenvironment Targeting and Transient Chemodynamic Cancer Therapy,” Journal Nanobiotechnology 20 (2020): 20.

[89] D. S. Zhang, M. Y. Zhu, Y. F. He, et al., “Efficient and Bright Broadband Electroluminescence Based on Environment-friendly Metal Halide Nanoclusters,” Light: Science & Applications 13 (2024): 82.

[90] Z. Y. Liu, M. Zhou, L. S. Luo, Y. T. Wang, E. Kahng, and R. C. Jin, “Elucidating the Near-Infrared Photoluminescence Mechanism of Homometal and Doped M25(SR)18 Nanoclusters,” Journal of the American Chemical Society 145 (2023): 19969–19981.

[91] A. L. Ma, J. W. Wang, Y. F. Wang, et al., “Atomically Precise M15 (M = Au/Ag/Cu) Alloy Nanoclusters: Structural Analysis, Optical and Electrocatalytic CO2 Reduction Properties,” Polyoxometalates 3 (2024): 9140054.

[92] X. Kang, X. Wei, S. Jin, et al., “Rational Construction of a Library of M29 Nanoclusters From Monometallic to Tetrametallic,” Proceedings of the National Academy of Sciences of the United States of America 116 (2019): 18834–18840.

[93] M. S. Bootharaju, C. P. Joshi, M. R. Parida, O. F. Mohammed, and O. M. Bakr, “Templated Atom-Precise Galvanic Synthesis and Structure Elucidation of a [Ag24Au(SR)18]⁻ Nanocluster,” Angewandte Chemie International Edition 55 (2016): 922–926.

[94] Q. Q. Yuan, X. Kang, D. Q. Hu, C. W. L. Qin, S. X. Wang, and M. Z. Zhu, “Metal Synergistic Effect on Cluster Optical Properties: Based on Ag25 Series Nanoclusters,” Dalton Transactions 48 (2019): 13190–13196.

[95] X. Kang, S. X. Wang, Y. B. Song, et al., “Bimetallic Au2Cu6 Nanoclusters: Strong Luminescence Induced by the Aggregation of Copper(I) Complexes With Gold(0) Species,” Angewandte Chemie International Edition 55 (2016): 3611–3614.

[96] X. Kang, X. W. Li, H. Z. Yu, et al., “Modulating Photo-luminescence of Au2Cu6 Nanoclusters via Ligand-engineering,” RSC Advances 7 (2017): 28606–28609.

[97] X. Liu, J. Y. Yuan, C. H. Yao, et al., “Crystal and Solution Photoluminescence of MAg24(SR)18 (M = Ag/Pd/Pt/Au) Nanoclusters and some Implications for the Photoluminescence Mechanisms,” Journal of Physical Chemistry C 121 (2017): 13848–13853.

[98] F. Hu, Z. C. Long, F. M. Zhao, W. Q. Shi, M. G. Zhou, and Q. M. Wang, “Anti-Heavy-Atom Effect Observed in Near-Infrared Emissive Bimetallic Nanoclusters Au28Cu12X4Cl4 (X = Cl, Br, and I),” Journal of the American Chemical Society 147 (2025): 19886–19892.

[99] X. J. Wang, B. Yin, L. R. Jiang, et al., “Ligand-protected Metal Nanoclusters as Low-loss, Highly Polarized Emitters for Optical Waveguides,” Science 381 (2023): 784–790.

[100] W. Q. Shi, L. L. Zeng, R. L. He, et al., “Near-unity NIR Phosphorescent Quantum Yield From a Room-temperature Solvated Metal Nanocluster,” Science 383 (2024): 326–330.

[101] V. Yadav, A. Jana, S. Acharya, et al., “Site-specific Substitution in Atomically Precise Carboranethiol-protected Nanoclusters and Concomitant Changes in Electronic Properties,” Nature Communications 16 (2025): 1197.

[102] D. Arima, S. Hidaka, S. Yokomori, et al., “Triplet-Mediator Ligand-Protected Metal Nanocluster Sensitizers for Photon Upconversion,” Journal of the American Chemical Society 146 (2024): 16630–16638.

[103] H. L. Liu, Z. L. Zhou, Z. W. Wang, et al., “Dual-Emission Au-Ag Nanoclusters With Enhanced Photoluminescence and Thermal Sensitivity for Intracellular Ratiometric Nanothermometry,” Biosensors 15 (2025): 510.

[104] X. J. Wang, K. Y. Kuang, M. M. Jing, X. Zhao, S. Chen, and M. Z. Zhu, “Progress in Electrochemiluminescence of Metal Nanoclusters,” Chemical Physics Reviews 5 (2024): 041310.

[105] Y. Liu, Y. Wang, and N. Pinna, “Atomically Precise Metal Nanoclusters for Photocatalytic Water Splitting,” ACS Materials Letters 6 (2024): 2995–3006.

[106] Z. B. Gan, Y. J. Lin, L. Luo, et al., “Fluorescent Gold Nanoclusters With Interlocked Staples and a Fully Thiolate-Bound Kernel,” Angewandte Chemie International Edition 55 (2016): 11567–11571.

[107] H. H. Deng, X. Q. Shi, F. F. Wang, et al., “Fabrication of Water-Soluble, Green-Emitting Gold Nanoclusters With a 65% Photoluminescence Quantum Yield via Host–Guest Recognition,” Chemistry of Materials 29 (2017): 1362–1369.

[108] T. Q. Yang, B. Peng, B. Q. Shan, et al., “Origin of the Photoluminescence of Metal Nanoclusters: From Metal-Centered Emission to Ligand-Centered Emission,” Nanomaterials 10 (2020): 261.

[109] Q. C. Peng, Y. B. Si, Z. Y. Wang, et al., “Thermally Activated Delayed Fluorescence Coinage Metal Cluster Scintillator,” ACS Central Science 9 (2023): 1419–1426.

[110] Z. Y. Liu, Q. B. Nie, B. L. Han, et al., “Atom-precise Coinage Metal Nanoclusters for near-infrared Emission: Excited-state Dynamics and Mechanisms,” Chemical Society Reviews 54 (2025): 9092–9115.

[111] K. L. D. M. Weerawardene and C. M. Aikens, “Origin of Photoluminescence of Ag 25 (SR) 18– Nanoparticles: Ligand and Doping Effect,” Journal of Physical Chemistry C 122 (2018): 2440–2447.

[112] M. Zhou, C. Zeng, M. Sfeir, et al., “Evolution of Excited-State Dynamics in Periodic Au 28 , Au 36 , Au 44 , and Au 52 Nanoclusters,” Journal of Physical Chemistry Letters 8 (2017): 4023–4030.

[113] S. Takano, H. Hirai, T. Nakashima, T. Iwasa, T. Taketsugu, and T. Tsukuda, “Photoluminescence of Doped Superatoms M@Au12 (M = Ru, Rh, Ir) Homoleptically Capped by (Ph2)PCH2P(Ph2): Efficient Room-Temperature Phosphorescence From Ru@Au 12,” Journal of the American Chemical Society 143 (2021): 10560–10564.

[114] K. Bharti, J. K. Sahu, and K. K. Sadhu, “Origin of Luminescence Properties and Synthetic Methods for Gold- and Bimetallic Gold-based Nanomaterials,” Advanced Materials 3 (2022): 5698–5724.

[115] Y. X. Chen, H. D. Yu, L. H. Wu, et al., “Unlocking Multi-photon Excited Luminescence in Pyrazolate Trinuclear Gold Clusters for Dynamic Cell Imaging,” Nature Communications 15 (2024): 7356.

[116] M. S. Devadas, J. Kim, E. Sinn, D. Lee, T. Goodson, and G. Ramakrishna, “Unique Ultrafast Visible Luminescence in Monolayer-Protected Au25 Clusters,” Journal of Physical Chemistry C 114 (2010): 22417–22423.

[117] Y. T. Wang, Z. Y. Liu, A. Mazumder, et al., “Tailoring Carbon Tails of Ligands on Au52(SR)32 Nanoclusters Enhances the Near-Infrared Photoluminescence Quantum Yield From 3.8 to 18.3%,” Journal of the American Chemical Society 145 (2023): 26328–26338.

[118] M. Zhou and Y. B. Song, “Origins of Visible and Near-Infrared Emissions in [Au25(SR)18]⁻ Nanoclusters,” Journal of Physical Chemistry Letters 12 (2021): 1514–1519.

[119] Y. Negishi, K. Nobusada, and T. Tsukuda, “Glutathione-Protected Gold Clusters Revisited: Bridging the Gap Between Gold(I)−Thiolate Complexes and Thiolate-Protected Gold Nanocrystals,” Journal of the American Chemical Society 127 (2005): 5261–5270.

[120] A. Fernando, K. Weerawardene, N. Karimova, and C. Aikens, “Quantum Mechanical Studies of Large Metal, Metal Oxide, and Metal Chalcogenide Nanoparticles and Clusters,” Chemical Reviews 115 (2015): 6112–6216.

[121] M. Wei, Y. Tian, L. J. Wang, Y. K. Hong, D. Luo, and Y. L. Sha, “The Emission Mechanism of Gold Nanoclusters Capped With 11-Mercaptoundecanoic Acid, and the Detection of Methanol in Adulterated Wine Model,” Materials 14 (2021): 6342.

[122] C. M. Aikens, “Geometric and Electronic Structure of Au25(SPhX)18− (X = H, F, Cl, Br, CH3, and OCH3),” Journal of Physical Chemistry Letters 1 (2010): 2594–2599.

[123] J. Qian, Z. C. Yang, J. K. Lyu, Q. F. Yao, and J. P. Xie, “Molecular Interactions in Atomically Precise Metal Nanoclusters,” Precision Chemistry 2 (2024): 495–517.

[124] Z. X. Luo and S. Q. Lin, “Advances in Cluster Superatoms for a 3D Periodic Table of Elements,” Coordination Chemistry Reviews 500 (2024): 215505.

[125] X. K. Wan, X. S. Han, Z. J. Guan, W. Q. Shi, J. J. Li, and Q. M. Wan, “Interplay of Kernel Shape and Surface Structure for NIR Luminescence in Atomically Precise Gold Nanorods,” Nature Communications 15 (2024): 7214.

[126] Q. Tang, F. H. Li, and D. E. Jiang, “Superatomic Au25(SC2H5)18 Nanocluster Under Pressure,” ACS Nanoscience Au 2 (2022): 40–48.

[127] X. Wang, Y. Zhong, T. T. Li, et al., “Sequential Addition of Cations Increases Photoluminescence Quantum Yield of Metal Nanoclusters near Unity,” Nature Communications 16 (2025): 587.

[128] C. J. Zeng, Y. X. Chen, G. Li, and R. C. Jin, “Magic Size Au64(S-c-C6H11)32 Nanocluster Protected by Cyclohexanethiolate,” Chemistry of Materials 26 (2014): 2635–2641.

[129] W. J. Du, S. Jin, L. Xiong, et al., “Ag 50 (Dppm) 6 (SR) 30 and Its Homologue AuxAg50–x(Dppm)6(SR)30 Alloy Nanocluster: Seeded Growth, Structure Determination, and Differences in Properties,” Journal of the American Chemical Society 139 (2017): 1618–1624.

[130] Z. B. Gan, Y. G. Liu, L. Wang, et al., “Distance Makes a Difference in Crystalline Photoluminescence,” Nature Communications 11 (2020): 5572.

[131] N. Zhang, L. Qu, S. H. Dai, et al., “Intramolecular Charge Transfer Enables Highly-efficient X-ray Luminescence in Cluster Scintillators,” Nature Communications 14 (2023): 2901.

[132] Z. Y. Liu, L. S. Luo, J. Kong, E. Kahng, M. Zhou, and R. C. Jin, “Bright near-infrared Emission From the Au 39 (SR) 29 Nanocluster,” Nanoscale 16 (2024): 7419–7426.

[133] W. H. Jiang, X. M. Zeng, M. J. Wu, L. Qin, L. Y. Yao, and G. Y. Yang, “Thermally Activated Delayed Fluorescence-Based Near-Infrared-II Luminescence and Controlled Size Growth of Silver Nanoclusters,” ACS Nano 19 (2025): 7129–7139.

[134] P. Kimber and F. Plasser, “Energy Component Analysis for Electronically Excited States of Molecules: Why the Lowest Excited State Is Not Always the HOMO/LUMO Transition,” Journal of Chemical Theory and Computation 19 (2023): 2340–2352.

[135] L. Tang, W. Zhang, Q. K. Han, B. Wang, M. Zhou, and S. X. Wang, “Sub-ångström bond length tuning enhances photoluminescence quantum yield in copper nanoclusters,” Nature Communications 16 (2025): 10715.

[136] L. S. Luo, Z. Y. Liu, X. S. Du, and R. C. Jin, “Near-Infrared Dual Emission From the Au 42 (SR) 32 Nanocluster and Tailoring of Intersystem Crossing,” Journal of the American Chemical Society 144 (2022): 19243–19247.

[137] Z. Y. Liu, Y. W. Li, E. Kahng, et al., “Tailoring the Electron–Phonon Interaction in Au 25 (SR) 18 Nanoclusters via Ligand Engineering and Insight Into Luminescence,” ACS Nano 16 (2022): 18448–18458.

[138] Y. Zhong, J. W. Zhang, T. T. Li, et al., “Suppression of Kernel Vibrations by Layer-by-layer Ligand Engineering Boosts Photoluminescence Efficiency of Gold Nanoclusters,” Nature Communications 14 (2023): 658.

[139] H. K. Zhang, Z. Zhao, A. T. Turley, et al., “Aggregate Science: From Structures to Properties,” Advanced Materials 32 (2020): 2001457.

[140] J. Z. Yan, S. Malola, C. Y. Hu, et al., “Co-crystallization of Atomically Precise Metal Nanoparticles Driven by Magic Atomic and Electronic Shells,” Nature Communications 9 (2018): 3357.

[141] Q. Li, C. J. Zeman IV, B. Kalkan, et al., “Direct Observation of the Pressure-Induced Structural Variation in Gold Nanoclusters and the Correlated Optical Response,” Nano Letters 23 (2023): 132–139.

[142] A. Domínguez-Castro and T. Frauenheim, “Impact of Vibronic Coupling Effects on Light-driven Charge Transfer in Pyrene-functionalized Middle and Large-sized Metalloid Gold Nanoclusters From Ehrenfest Dynamics,” Physical Chemistry Chemical Physics 23 (2021): 17129–17133.

[143] J. N. Sun, X. J. Zhang, Z. K. Gong, and H. Xu, “Near-infrared Phosphorescence From Metal Nanoclusters With Nearly Unity Quantum Yield,” Innovation Materials 2 (2024): 100065.

[144] T. T. Li, H. F. Zhu, and Z. N. Wu, “Viewing Aggregation-Induced Emission of Metal Nanoclusters From Design Strategies to Applications,” Nanomaterials 13 (2023): 470.

[145] M. Q. Zhu, Q. F. Yao, Z. H. Liu, et al., “Aggregation-Induced Emission of Gold Nanoclusters by Ionic Liquids for White Light-Emitting Diode and Multiple-Ion Probe Applications,” Physical Chemistry Letters 13 (2022): 7722–7730.

[146] W. Y. Liang, H. L. Wang, P. X. Lu, et al., “Cocrystallization of Binary Silver Clusters into Supramolecular Assembly to Regulate Aggregation-Induced Emission and Thermally Activated Delayed Fluorescence,” Aggregate 6 (2025): e70019.

[147] Y. L. Li, W. Y. Xi, I. Hussain, M. L. Chen, and B. Tan, “Facile Preparation of Silver Nanocluster Self-assemblies With Aggregation-induced Emission by Equilibrium Shifting,” Nanoscale 13 (2021): 14207–14213.

[148] Q. Li, C. J. Zeman 4th, B. Kalkan, et al., “Direct Observation of the Pressure-Induced Structural Variation in Gold Nanoclusters and the Correlated Optical Response,” Nano Letters 23 (2023): 132–139.

[149] G. Zhang, B. L. Fang, J. Peng, S. L. Deng, L. M. Hu, and W. H. Lai, “Luminescent Gold Nanoclusters From Synthesis to Sensing: A Comprehensive Review,” Chemical Engineering Journal 503 (2025): 158294.

[150] E. D. Wang and Y. Gao, “Relativistic Effect Influencing the Diverse Bonding Character of the Interfacial Ag Staple Motifs in Thiolate-protected Nanoclusters,” Journal of Chemical Physics 160 (2024): 114305.

[151] M. Gutiérrez, Y. Zhang, and J. C. Tan, “Confinement of Luminescent Guests in Metal-Organic Frameworks: Understanding Pathways from Synthesis and Multimodal Characterization to Potential Applications of LG@MOF Systems,” Chemical Reviews 122 (2022): 10438.

[152] Y. K. Saito, A. Suda, M. Sakai, et al., “Controlled Nanocrystallization of Gold Nanoclusters Within Surfactant Envelopes: Enhancing Aggregation-induced Emission in Solution,” Chemical Science 15 (2024): 11775–11782.

[153] A. Muñoz-Castro and R. Arratia-Pere, “Spin–orbit Effects in Cluster Chemistry: Considerations and Applications for Rationalization of Their Properties,” Chemical Physics Reviews 4 (2023): 021313.

[154] A. I. Krylov, “From Orbitals to Observables and Back,” Journal of Chemical Physics 153 (2020): 080901.

[155] C. Y. Yi, H. J. Zheng, P. J. Herbert, Y. X. Chen, R. C. Jin, and K. L. Knappenberger Jr, “Ligand- and Solvent-Dependent Electronic Relaxation Dynamics of Au25(SR)18– Monolayer-Protected Clusters,” Journal of Physical Chemistry C 121 (2017): 24894–24902.

[156] S. A. Miller, J. M. Womick, J. F. Parker, R. W. Murray, and A. M. Moran, “Femtosecond Relaxation Dynamics of Au25L18−Monolayer-Protected Clusters,” Journal of Physical Chemistry C 113 (2009): 9440–9444.

[157] H. F. Qian, M. Y. Sfeir, and R. C. Jin, “Ultrafast Relaxation Dynamics of [Au25(SR)18] Q Nanoclusters: Effects of Charge State,” Journal of Physical Chemistry C 114 (2010): 19935–19940.

[158] T. D. Green and K. L. Knappenberger, “Relaxation Dynamics of Au25L18 Nanoclusters Studied by Femtosecond Time-resolved near Infrared Transient Absorption Spectroscopy,” Nanoscale 4 (2012): 4111.

[159] J. Kong, W. Zhang, Y. Z. Wu, and M. Zhou, “Optical Properties of Gold Nanoclusters Constructed From Au13 Units,” Aggregate 3 (2022): e207.

[160] J. Kong, Z. R. Kuang, W. Zhang, et al., “Robust Vibrational Coherence Protected by a Core–shell Structure in Silver Nanoclusters,” Chemical Science 15 (2024): 6906–6915.

[161] M. S. Devadas, V. D. Thanthirige, S. Bairu, E. Sinn, and G. Ramakrishna, “Temperature-Dependent Absorption and Ultrafast Luminescence Dynamics of Bi-Icosahedral Au25 Clusters,” Journal of Physical Chemistry C 117 (2013): 23155–23161.

[162] F. Cao, C. Xu, W. Zhang, et al., “Dual-Quartet Phosphorescent Emission in the Open-Shell M₁Ag₁₃ (M = Pt, Pd) Nanoclusters,” Nature Communications 15 (2024): 5962.

[163] D. E. Jiang and S. Dai, “From Superatomic Au25(SR)18− to Superatomic M@Au24(SR)18q Core−Shell Clusters,” Inorganic Chemistry 48 (2009): 2720–2722.

[164] X. Liu, W. W. Xu, X. Y. Huang, et al., “De Novo Design of Au36(SR)24 Nanoclusters,” Nature Communications 11 (2020): 3349.

[165] H. H. Deng, K. Y. Huang, L. F. Xiu, et al., “Bis-Schiff Base Linkage-triggered Highly Bright Luminescence of Gold Nanoclusters in Aqueous Solution at the Single-cluster Level,” Nature Communications 13 (2022): 3381.

[166] M. Walter, J. Akola, O. Lopez-Acevedo, et al., “A Unified View of Ligand-protected Gold Clusters as Superatom Complexes,” Proceedings of the National Academy of Sciences of United States of America 105 (2008): 9157–9162.

[167] X. Y. Ding, C. K. Zhang, L. X. Shi, et al., “Synergistic Coordination of Diphosphine With Primary and Tertiary Phosphorus Centers: Ultrastable Icosidodecahedral Ag30 Nanoclusters With Metallic Aromaticity,” Science Advances 10 (2024): eads0728.

[168] X. Wang, Z. Y. Liu, J. J. Wang, et al., “Electronic Structure and Aromaticity of an Unusual Cyclo[18]Carbon Precursor, C18Br6**,” Chemistry – A European Journal 29 (2023): e202300348.

[169] Z. Y. Liu, T. Lu, S. G. Hua, and Y. Yu, “Aromaticity of Hückel and Möbius Topologies Involved in Conformation Conversion of Macrocyclic [32]Octaphyrin(1.0.1.0.1.0.1.0): Refined Evidence From Multiple Visual Criteria,” Journal of Physical Chemistry C 123 (2019): 18593–18599.

[170] D. Kim, H. Ki, D. Im, et al., “Excited-State Structural Dynamics of the Cubane-Type Metal Cluster [Cu 4 I 4 (py) 4] Explored by Time-Resolved X-Ray Liquidography,” Advanced Science 12 (2025): 2414970.

[171] Y. X. Chen, M. Zhou, Q. Li, H. Gronlund, and R. C. Jin, “Isomerization-induced Enhancement of Luminescence in Au28(SR)20 Nanoclusters,” Chemical Science 11 (2020): 8176–8183.

[172] L. Y. Chen, C. W. Wang, Z. Yuan, and H. T. Chang, “Fluorescent Gold Nanoclusters: Recent Advances in Sensing and Imaging,” Analytical Chemistry 87 (2015): 216–229.

[173] Y. Xiao, Z. N. Wu, Q. F. Yao, and J. P. Xie, “Luminescent Metal Nanoclusters: Biosensing Strategies and Bioimaging Applications,” Aggregate 2 (2021): 114–132.

[174] M. Galchenko, A. Black, L. Heymann, and C. Klinke, “Field Effect and Photoconduction in Au25 Nanoclusters Films,” Advanced Materials 31 (2019): 1900684.

[175] M. A. Abbas, P. V. Kamat, and J. H. Bang, “Thiolated Gold Nanoclusters for Light Energy Conversion,” ACS Energy Letters 3 (2018): 840–854.

[176] J. X. Lu, B. Y. Shao, R. W. Huang, et al., “High-Efficiency Circularly Polarized Light-Emitting Diodes Based on Chiral Metal Nanoclusters,” Journal of the American Chemical Society 146 (2024): 4144–4152.

RIGHTS & PERMISSIONS

2026 The Author(s). Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.