Construction of novel Ag(0)-containing silver nanoclusters by regulating auxiliary phosphine ligands

Abstract

Controlled synthesis of metal clusters through minor changes in surface ligands holds significant interest because the corresponding entities serve as ideal models for investigating the ligand environment's stereochemical and electronic contributions that impact the corresponding structures and properties of metal clusters. In this work, we obtained two Ag(0)-containing nanoclusters (Ag₁₇ and Ag₃₂) with near-infrared emissions by regulating phosphine auxiliary ligands. Ag₁₇ and Ag₃₂ bear similar shells wherein Ag₁₇ features a trigonal bipyramid Ag₅ kernel while Ag₃₂ has a bi-icosahedral interpenetrating an Ag₂₀ kernel. Ag₁₇ and Ag₃₂ showed a near-infrared emission (NIR) of around 830 nm. Benefiting from the rigid structure, Ag₁₇ displayed a more intense near-infrared emission than Ag₃₂. This work provides new insight into the construction of novel superatomic silver nanoclusters by regulating phosphine ligands.

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Introduction

Metal nanoclusters have attracted wide attention because of their atom-precise structures and quantum size effects, which provide an ideal platform for investigating the connection between simple metal complexes and bulk metal nanoparticles.^1–16 In addition, their potential applications in optics,^17–20 catalysis,^21–25 and biomedicine^26–28 encourage us to synthesize novel structured nanoclusters to exploit versatile properties. Among these, nanoclusters with valence electron structures similar to atomic electron structures are considered “superatomic nanoclusters”.^29–34 The regulation of superatomic nanocluster structures and nuclearities is beneficial for broadening the diversity of properties and facilitating the exploration of the structure–property correlation at the atomic level. The synthesis of structurally well-defined Ag(0)-containing nanoclusters has been performed for over a decade, but the instability of silver nanoclusters restricts their structural modulation.^35–39

Currently, several effective methods have been developed to fine-tune the nanocluster structures, including heterometal doping,^40–42 ligand engineering,^43–48 counter ion template,^49–52 and so on. The ligand engineering strategy is considered one of the most effective ways to regulate the structure and supramolecular assembly of nanoclusters. Ligand engineering strategies have been reported to adjust the structures and properties of nanoclusters by the steric hindrance effect, electron-withdrawing and donating effects, etc.^53,54 Surface ligand regulation includes the primary ligands (such as thiolate ligands) and auxiliary ligands. Although manipulating primary ligands is effective for achieving higher nuclearities and electron counts, it is often a time-consuming and laborious process.^55–57 In contrast, the use of readily available auxiliary ligands, such as phosphine ligands, has the potential to be more efficient.^58,59

Herein, by regulating the auxiliary phosphine ligands, we synthesized two cases of superatomic silver nanoclusters, formulated as [Ag₁₇(L)₁₂(PPh₃)₆](NO₃)₃ (L = quinoline-2-thiol (deprotonation)-4-carboxyl, PPh₃ = triphenylphosphine, denoted as Ag₁₇) and [Ag₃₂(L)₁₈(P(Ph-^pCH₃)₃)₆Cl₂](NO₃)₄ (L = quinoline-2-thiol (deprotonation)-4-carboxyl, P(Ph-^pCH₃)₃ = tri-p-tolylphosphine, denoted as Ag₃₂). The atomically precise structures of two silver nanoclusters were determined by single-crystal X-ray diffraction (SC-XRD) and further confirmed by electrospray ionization mass spectrometry (ESI-MS) measurements. Both Ag₁₇ and Ag₃₂ feature Ag₄L₄P₂ unit-based surface structures, but Ag₁₇ has an Ag₅ trigonal bipyramid kernel while Ag₃₂ has the Ag₂₀ inner core with the fusion of two classical Ag₁₃ icosahedrons. Both of them have emissions in the near-infrared region under ambient temperature. The quantum yield of the Ag₁₇ solution is 3.09%, while the quantum yield of the Ag₃₂ solution is below 0.1%. Ag₁₇ shows superior luminescence properties compared to Ag₃₂ due to its rigid surface structure.

Experimental section

Materials and reagents

All chemicals and solvents obtained from suppliers were used without further purification. All solvents were analytical-grade reagents. Silver nitrate (AgNO₃, 98%), triphenylphosphine (PPh₃, 97%), tri-p-tolylphosphine (P(Ph-^pCH₃)₃, 97%), 2-chloroquinoline-4-carboxylic acid (2-Cl-4-COOH-QL, 96%), thiourea (CH₄N₂S, 99%), sodium borohydride (NaBH₄, 98%), sodium hydroxide (NaOH, 98%), and hydrochloric acid (HCl, 38%) were used.

Synthesis of quinoline-2-thiol (deprotonation)-4-carboxyl (L)

L was synthesized according to the procedures described in the literature.⁶⁰ 2-Cl-4-COOH-QL (1 mol) was added to the EtOH solution of thiourea (1.2 mol) and the mixture was refluxed for 15–30 min. Then the solution was diluted to twice its volume with H₂O, and the yellow product obtained was dissolved in 10% NaOH. The yellow filtrate was acidified with 10% HCl and the yellow precipitate obtained was collected by filtration, washed with H₂O, and dried. It was recrystallized from EtOH to give yellowish-orange needles. The ¹H NMR spectra confirmed the structure (Fig. S1, ESI†). δ = 13.99 (s, 1H), 8.34–8.33 (d, 1H), 7.69–7.68 (d, 2H), 7.58 (d, 1H), 7.43–7.40 (m, 1H).

Synthesis of [Ag₁₇(L)₁₂(PPh₃)₆](NO₃)₃ (Ag₁₇)

AgNO₃ (12 mg, 0.07 mmol) was dissolved in a mixed solvent of 4 mL of methanol and 4 mL of dichloromethane at room temperature. Then L (10 mg, 0.05 mmol) and PPh₃ (13 mg, 0.05 mmol) were added under vigorous stirring to afford Ag–S–P complex. About 5 min later, freshly prepared NaBH₄ (2 mg, 0.052 mmol) in 1 mL of methanol was added dropwise under stirring. The color of the solution changed from yellow to brown–black. Five hours later, the brown–black solution was collected after centrifuging. The mixture evaporated slowly at room temperature and orange crystals were obtained for five days. Yield: 15% (based on Ag). Elemental analysis (found (calcd.), %; based on C₂₂₈H₁₆₂Ag₁₇N₁₅O₃₃P₆S₁₂): C, 44.86 (45.31); H, 2.62 (2.70); N, 3.19 (3.48); S, 6.48 (6.37); O 8.54 (8.74).

Synthesis of [Ag₃₂(L)₁₈(P(Ph-^pCH₃)₃)₆Cl₂](NO₃)₄ (Ag₃₂)

AgNO₃ (17 mg, 0.1 mmol) was dissolved in a mixed solvent of 4 mL of methanol and 4 mL of dichloromethane at room temperature. Then L (12 mg, 0.06 mmol) and P(Ph-^pCH₃)₃ (25 mg, 0.082 mmol) were added under vigorous stirring. About 5 min later, freshly prepared NaBH₄ (2 mg, 0.052 mmol) in 1 mL of methanol was added dropwise under stirring. The color of the solution changed from yellow to brown–black. Five hours later, the brown–black solution was collected after centrifuging. The mixture evaporated slowly at room temperature and black block crystals were obtained for five days. Yield: 27% (based on Ag). Elemental analysis (found (calcd.), %; based on C₃₀₆H₂₃₄Ag₃₂N₂₂O₄₈P₆S₁₈Cl₂): C, 39.91 (39.64); H, 2.32 (2.54); N, 3.41 (3.32); S, 6.39 (6.22); O, 8.35 (8.28).

Characterization

¹H NMR spectroscopy was carried out on a Bruker 400 spectrometer operating at 600 MHz with DMSO-d6 as the solvent. Electrospray ionization mass spectrometry (ESI-MS) was performed on a X500R QTOF spectrometer. Powder X-ray diffraction (PXRD) patterns of the samples were recorded on a D/MAX-3D diffractometer. Elemental analyses (EA) were carried out with a PerkinElmer 240 elemental analyzer. Fourier transform infrared (FT-IR) spectra were recorded on a Bruker ALPHA II spectrometer. UV-vis absorption spectra were obtained by means of a Hitachi UH4150 UV-visible spectrophotometer. The NIR luminescence spectra were measured with an Edinburgh FLS 980 fluorescence spectrometer. The luminescence lifetime was measured on an Edinburgh FLS 980 fluorescence spectrometer operating in time-correlated single-photon counting (TCSPC) mode. The quantum yield (QY) was measured using an integrating sphere on an Edinburgh FLS 980 fluorescence spectrometer. X-ray photoelectron spectroscopy (XPS) was conducted using a Thermo ESCALAB 250XI with Al Kα radiation as the excitation source. C 1s calibrated binding energies at 284.8 eV. Energy-dispersive spectroscopy and elemental mapping measurements were performed via a Zeiss Sigma 500.

Results and discussion

Ag₁₇ and Ag₃₂ were prepared by a one-pot reduction method. Briefly for Ag₁₇, AgNO₃ was dissolved in a mixed solvent of methanol and dichloromethane at room temperature followed by the addition of L and PPh₃ under vigorous stirring to afford the Ag–S–P complex. Subsequently, freshly prepared NaBH₄ in methanol was added dropwise under stirring. The color of the solution changed from yellow to brown–black. The raw product solution was collected after centrifuging. Orange crystals were obtained by evaporating slowly in darkness for five days. Ag₃₂ was prepared by a similar method but with P(Ph-^pCH₃)₃ instead of PPh₃, and the black block crystals of Ag₃₂ were obtained (Scheme 1).

Scheme 1 Synthetic routes for Ag₁₇ and Ag₃₂.

The chemical compositions of Ag₁₇ and Ag₃₂ were confirmed by electrospray ionization mass spectroscopy (ESI-MS). As shown in Fig. 1a, the ESI-MS spectrum of Ag₁₇ shows a prominent signal at m/z 1952.70, which corresponds to the [Ag₁₇(PPh₃)₆(L)₁₂]³⁺ species (calcd. m/z 1952.69). Ag₁₇ exhibits a 2-electron configuration (17 − 12 − 3 = 2e). As shown in Fig. 1b, the ESI-MS spectrum of Ag₃₂ shows a prominent signal at m/z 2256.26, which corresponds to the [Ag₃₂(P(Ph-^pCH₃)₃)₆(L)₁₈Cl₂]⁴⁺ species (calcd. m/z 2256.24). It bears an eight-electron closed-shell (32 − 18 − 2 − 4 = 8e) structure. The presence of NO₃⁻ in Ag₁₇ and Ag₃₂ was also confirmed by Fourier transform infrared (FT-IR) spectra and negative-ion mode ESI-MS spectra (Fig. S2 and S3, ESI†). Powder X-ray diffraction (PXRD) further verified the phase purity of Ag₁₇ and Ag₃₂ (Fig. S4, ESI†). X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectrometry (EDS) elemental mapping of Ag₁₇ and Ag₃₂ revealed all of the expected elements and the presence of Ag(0) in Ag₁₇ and Ag₃₂ (Fig. S5–S8, ESI†).

Fig. 1 (a) Positive-ion mode ESI-MS of Ag₁₇ in CH₃OH. (Inset) Measured (black line) and simulated (red line) isotopic distribution patterns of the molecular ion peak. (b) Positive-ion mode ESI-MS of Ag₃₂ in CH₃OH. (Inset) Measured (black line) and simulated (red line) isotopic distribution patterns of the molecular ion peak.

Single-crystal X-ray diffraction (SC-XRD) analysis revealed that Ag₁₇ crystallized in the P3̄1c space group. The overall structure of Ag₁₇ shows a 3-fold rotational symmetry (Fig. 2a and Fig. S9, ESI†). Ag₁₇ has an Ag₅ trigonal bipyramid (Fig. 2b) covered by the Ag₁₂(L)₁₂(PPh₃)₆ shell (Fig. S10a, ESI†). The 3-fold axis passes through the top and bottom of the two vertexes of the kernel. Thus, the Ag₁₂(L)₁₂(PPh₃)₆ shell could be regarded as a trimeric structure of the Ag₄L₄(PPh₃)₂ unit (Fig. 2c and d). Each Ag₄L₄(PPh₃)₂ is located on one side of the trigonal bipyramid. The thiolates in the “equatorial” position of the kernel adopt a μ₄ bridging mode and the other thiolates near the vertexes of the kernel adopt a μ₃ bridging mode. The Ag atoms located above the triangular Ag₃ face of the Ag₅ trigonal bipyramid are quadruply coordinated to three sulfur atoms of three L ligands and one phosphorus atom of PPh₃. The other Ag atoms located near vertexes of the kernel are quadruply coordinated to two sulfur atoms and two nitrogen atoms of the neighboring two L ligands. In addition, the free carboxylic acid functional groups impart potential for post-modification to Ag₁₇.

Fig. 2 (a) The overall structure of Ag₁₇. (b) The Ag₅ kernel of Ag₁₇. (c) The Ag₄S₄ motif of Ag₁₇. (d) The Ag₁₇ peripheral Ag₄L₄(PPh₃)₂ unit. (e) The overall structure of Ag₃₂. (f) The Ag₂₀ kernel of Ag₃₂ (the polyhedron highlighted is an Ag₅ unit). (g) The Ag₄S₆ motif of Ag₃₂. (h) The Ag₃₂ peripheral Ag₄L₆(P(Ph-^pCH₃)₃)₂ unit. Atom colors: Ag, dark green, turquoise and orange; P, purple; N, blue; S, yellow; Cl, light green; C, gray; O, red. All hydrogen atoms are omitted for clarity.

Ag₃₂ adopts the P4̄3n space group with a formula [Ag₃₂(P(Ph-^pCH₃)₃)₆(L)₁₈Cl₂]. The overall structure of Ag₃₂ is shown in Fig. 2e. Structurally, Ag₃₂ features an Ag₂₀ kernel, which is the fusion of two classical Ag₁₃ icosahedrons (Fig. 2f). Alternatively, the Ag₂₀ kernel could also be regarded as the fusion of the Ag₅ trigonal bipyramid by sharing the icosahedral central Ag atom. Probably due to Ag₁₇ and Ag₃₂ having an Ag₅ trigonal bipyramid-based kernel, they have similar surface structures (Fig. S10b, ESI†). Compared to Ag₁₇ with a trimeric structure of Ag₄L₄(PPh₃)₂ units, Ag₃₂ has three monomeric Ag₄L₄(P(Ph-^pCH₃)₃)₂ units (Fig. 2g and h). The additional two L ligands capping the Ag₄L₄(P(Ph-^pCH₃)₃)₂ units prevent their polymerization. There are two Cl-terminated atoms at both ends of Ag₂₀, and each Cl atom caps the Ag₃ triangular face (Fig. S11, ESI†). Each silver atom of the Ag₃ triangular face is not only coordinated with Cl but also protected by S and N (deprotonation) from two quinoline ligands. The distances between Ag and Cl atoms in Ag₃₂ were 2.589 and 2.606 Å (average 2.60 Å), which were not only much shorter than the sum of van der Waals radii of Ag and Cl atoms (1.72 Å + 1.80 Å = 3.52 Å), but also shorter than the sum of the atomic radii of Ag and Cl atoms (1.44 Å + 1.62 Å = 3.06 Å). Accordingly, the interactions between Ag and Cl atoms in Ag₃₂ could be considered covalent interactions. The Ag–Ag bond distances of Ag₃ are 3.276 Å and 3.288 Å. The average Ag–Ag distance between the Ag atoms in the outer shell to the core in Ag₃₂ is 2.9575 Å, which is shorter than that of Ag₁₇ (3.3109 Å). All the thiolates in Ag₃₂ are μ₃ coordination modes. Twelve of the -SR groups were co-coordinated with two Ag atoms in the core and one Ag atom in the shell layer, and the remaining six -SR groups were coordinated with one Ag atom in the core and two Ag atoms in the shell layer. Due to the change of the phosphine ligand (replace PPh₃ with P(Ph-^pCH₃)₃), the π⋯π interactions (Fig. S12, ESI†) and the change in steric hindrance caused by the alteration of the phosphine ligand, which affected the arrangement of the peripheral ligands, ultimately resulted in two different structures of Ag₁₇ and Ag₃₂.

As illustrated in Fig. 3a and b, Ag₁₇ and Ag₃₂ in CH₃OH exhibit distinct UV-vis absorption spectra with molecule-like optical transitions. The UV-vis spectrum of Ag₁₇ shows optical absorption bands at 330, 387, 487, and 597 nm. Likewise, Ag₃₂ has absorptions at 357, 499, and 653 nm. The similar absorption in the high-energy region may derived from their similar surface structures. To gain an insight into the electronic structures and absorption characteristics of Ag₁₇ and Ag₃₂, time-dependent density functional theory (TD-DFT) calculations were performed to simulate the optical absorptions (Fig. 3, Fig. S13 and S14, ESI†). The calculated UV-vis absorption spectra of Ag₁₇ and Ag₃₂ match well with the experimental ones with slight shifts. For Ag₁₇, the transition for the peaks of 423 nm is mainly from the outer shell. The lowest-energy absorption band at 618.2 nm is attributed to electronic transition from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO). For the Ag₃₂, the transitions for the peaks of 362.5 nm and 451.0 nm are from the outer shell. The lowest-energy absorption band at 597.7 nm is attributed to the electronic transition from the HOMO to the LUMO. The two nanoclusters of 2e Ag₁₇ and 8e Ag₃₂ exhibit clear super-atomic orbital characteristics with 1S² and 1S²1P⁶ (Fig. S15, ESI†).

Fig. 3 Experimental (black) and calculated (red) absorption spectra of Ag₁₇ (a) and Ag₃₂ (b) in CH₃OH.

Both Ag₁₇ and Ag₃₂ have emissions in the near-infrared region in solution (Fig. 4 and Fig. S16, ESI†). The Ag₁₇ NCs in CH₃OH show the maximum emission peak remaining at 830 nm. The HOMO of Ag₁₇ mainly lies on the Ag₅ kernel, while the LUMO is located on the surface ligands. Thus, the emission is mainly derived from the metal-to-ligand charge transfer (MLCT). The Ag₃₂ nanocluster in CH₃OH shows the maximum emission peak at 840 nm, mainly from the mixed MLCT and cluster-centered transition. It can be found that the luminescence intensity of Ag₁₇ is an order of magnitude higher than that of Ag₃₂. The quantum yield (QY) of Ag₁₇ in the CH₃OH solution is 3.09%, while the QY of Ag₃₂ is below 0.1%. The lifetimes of Ag₁₇ and Ag₃₂ are 1.47 μs and 1.61 μs (Fig. S17 and S18, ESI†), respectively, indicating phosphorescence. Similarly, the emission peak intensity of Ag₁₇ in the near-infrared region is stronger than that of Ag₃₂ in the solid state (Fig. S19 and S20, ESI†). As mentioned above in the structural analysis section, Ag₁₇ has a trimeric structure of Ag₄L₄(PPh₃)₂ units and Ag₃₂ has three discrete monomeric Ag₄L₄(P(Ph-^pCH₃)₃)₂ units. Therefore, the rigid structure of Ag₁₇ decreases the nonradiative decay, resulting in enhanced luminescence. Besides, rotation of the methyl groups on the phosphine ligands of Ag₃₂ also dissipates energy, facilitating nonradiative decay that converts light into heat.⁶¹

Fig. 4 Emission spectra of Ag₁₇ and Ag₃₂ in CH₃OH solution (excited at 400 nm).

Conclusions

In conclusion, we synthesized two new superatomic silver nanoclusters Ag₁₇ and Ag₃₂ by adjusting phosphine ligands. The structural anatomy indicated that the kernel of Ag₁₇ is Ag₅ and the kernel of Ag₃₂ is Ag₂₀. The inner cores of Ag₁₇ and Ag₃₂ have huge distinctions while the peripheral Ag–S motifs have some similarities. In addition, both the solution states and the solid states of Ag₁₇ and Ag₃₂ have luminescence properties in the near-infrared region. Due to the rigid structure of Ag₁₇ and the high-frequency vibrations of the methyl groups of Ag₃₂, Ag₁₇ shows stronger near-infrared emission intensity and higher QY. This work provides new insight into the construction of novel superatomic silver nanoclusters by co-reduction by regulating phosphine ligands.

Author contributions

Qing-Qing Ma and Xue-Jing Zhai: investigation, data curation, formal analysis and writing – original draft; Jia-Hong Huang: writing – original draft and validation; Yubing Si: theoretical simulation; Xi-Yan Dong: conceptualization, writing – review & editing and funding acquisition; Shuang-Quan Zang: supervision and funding acquisition; and Thomas C. W. Mak: supervision.

Conflicts of interest

There are no conflicts to declare.

Acknowledgements

This work was supported by the National Natural Science Foundation of China (No. U21A20277, 92061201), the Excellent Youth Foundation of Henan Scientific Committee (232300421022) and the Thousand Talents (Zhongyuan Scholars) Program of Henan Province (234000510007).

References

1. R. Jin, C. Zeng, M. Zhou and Y. Chen, Chem. Rev., 2016, 116, 10346–10413.
2. Z. Lei, X.-K. Wan, S.-F. Yuan, Z.-J. Guan and Q.-M. Wang, Acc. Chem. Res., 2018, 51, 2465–2474.
3. Y. Jin, C. Zhang, X.-Y. Dong, S.-Q. Zang and T. C. W. Mark, Chem. Soc. Rev., 2021, 50, 2297–2319.
4. X. Kang, Y. Li, M. Zhu and R. Jin, Chem. Soc. Rev., 2020, 49, 6443–6514.
5. Y.-M. Su, Z. Wang, C.-H. Tung, D. Sun and S. Schein, J. Am. Chem. Soc., 2021, 143, 13235–13244.
6. X.-Y. Dong, Y. Si, J.-S. Yang, C. Zhang, Z. Han, P. Luo, Z.-Y. Wang, S.-Q. Zang and T. C. W. Mak, Nat. Commun., 2020, 11, 3678.
7. M. S. Bootharaju, S. Lee, G. Deng, S. Malola, W. Baek, H. Häkkinen, N. Zheng and T. Hyeon, Angew. Chem., Int. Ed., 2021, 60, 9038–9044.
8. J.-H. Huang, Z.-Y. Wang, S.-Q. Zang and T. C. W. Mak, ACS Cent. Sci., 2020, 6, 1971–1976.
9. A. C. Templeton, W. P. Wuelfing and R. W. Murray, Acc. Chem. Res., 2000, 33, 27–36.
10. R. H. Adnan, J. M. L. Madridejos, A. S. Alotabi, G. F. Metha and G. G. Andersson, Adv. Sci., 2022, 9, 2105692.
11. F. Hu, R.-L. He, Z.-J. Guan, C.-Y. Liu and Q.-M. Wang, Angew. Chem., Int. Ed., 2023, 62, e202304134.
12. K. H. Wijesinghe, N. A. Sakthivel, T. Jones and A. Dass, J. Phys. Chem. Lett., 2020, 11, 6312–6319.
13. K. L. D. M. Weerawardene, P. Pandeya, M. Zhou, Y. Chen, R. Jin and C. M. Aikens, J. Am. Chem. Soc., 2019, 141, 18715–18726.
14. N. A. Sakthivel, M. Shabaninezhad, L. Sementa, B. Yoon, M. Stener, R. L. Whetten, G. Ramakrishna, A. Fortunelli, U. Landman and A. Dass, J. Am. Chem. Soc., 2020, 142, 15799–15814.
15. O. Lopez-Acevedo, H. Tsunoyama, T. Tsukuda, H. Häkkinen and C. M. Aikens, J. Am. Chem. Soc., 2010, 132, 8210–8218.
16. C. P. Joshi, M. S. Bootharaju, M. J. Alhilaly and O. M. Bark, J. Am. Chem. Soc., 2015, 137, 11578–11581.
17. X.-J. Zhai, J.-H. Hu, J. Guan, Y. Si, X.-Y. Dong, P. Luo, F. Pan, Z. Yu, R. Han and S.-Q. Zang, Nano Res., 2023, 16, 11366–11374.
18. S. Biswas and Y. Negishi, J. Phys. Chem. Lett., 2024, 15, 947–958.
19. R.-W. Huang, Y.-S. Wei, X.-Y. Dong, X.-H. Wu, C.-X. Du, S.-Q. Zang and T. C. W. Mark, Nat. Chem., 2017, 9, 689–697.
20. W.-M. He, Z. Zhou, Z. Han, S. Li, Z. Zhou, L.-F. Ma and S.-Q. Zang, Angew. Chem., Int. Ed., 2021, 60, 8505–8509.
21. S. Biswas, S. Das and Y. Negishi, Nanoscale Horiz., 2023, 8, 1509–1522.
22. T. Kawawaki, T. Okada, D. Hirayama and Y. Negishi, Green Chem., 2024, 26, 122–163.
23. X.-K. Wan, J.-Q. Wang, Z.-A. Nan and Q.-M. Wang, Sci. Adv., 2017, 3, e1701823.
24. Y. Lei, F. Mehmood, S. Lee, J. Greeley, B. Lee, S. Seifert, R. E. Winans, J. W. Elam, R. J. Meyer, P. C. Redfern, D. Teschner, R. Schlögl, M. J. Pellin, L. A. Curtiss and S. Vajda, Science, 2010, 328, 224–228.
25. M. Cao, R. Pang, Q.-Y. Wang, Z. Han, Z.-Y. Wang, X.-Y. Dong, S.-F. Li, S.-Q. Zang and T. C. W. Mak, J. Am. Chem. Soc., 2019, 141, 14505–14509.
26. J. Yang, F. Yang, C. Zhang, X. He and R. Jin, ACS Mater. Lett., 2022, 4, 1279–1296.
27. Y. Hua, Z.-H. Shao, A. Zhai, L.-J. Zhang, Z.-Y. Wang, G. Zhao, F. Xie, J.-Q. Liu, X. Zhao, X. Chen and S.-Q. Zang, ACS Nano, 2023, 17, 7837–7846.
28. Z. Yang, R. Shi, X. Liu, Q. Zhang, M. Chen, Y. Shen, A. Xie and M. Zhu, ACS Mater. Lett., 2023, 5, 2361–2368.
29. T.-H. Huang, F.-Z. Zhao, Q.-L. Hu, Q. Liu, T.-C. Wu, D. Zheng, T. Kang, L.-C. Gui and J. Chen, Inorg. Chem., 2020, 59, 16027–16034.
30. P. Luo, S. Bai, X. Wang, J. Zhao, Z.-N. Yan, Y.-F. Han, S.-Q. Zang and T. C. W. Mark, Adv. Opt. Mater., 2021, 9, 2001936.
31. M. Zhu, C. M. Aikens, F. J. Hollander, G. C. Schatz and R. Jin, J. Am. Chem. Soc., 2008, 130, 5883–5885.
32. M. W. Heaven, A. Dass, P. S. White, K. M. Holt and R. W. Murray, J. Am. Chem. Soc., 2008, 130, 3754–3755.
33. R. S. Dhayal, J.-H. Liao, Y.-C. Liu, M.-H. Chiang, S. Kahlal, J.-Y. Saillard and C. W. Liu, Angew. Chem., Int. Ed., 2015, 54, 3702–3706.
34. L. G. AbdulHalim, M. S. Bootharaju, Q. Tang, S. Del Gobbo, R. G. AbdulHalim, M. Eddaoudi, D.-E. Jiang and O. M. Bark, J. Am. Chem. Soc., 2015, 137, 11970–11975.
35. A. Desireddy, B. E. Conn, J. Guo, B. Yoon, R. N. Barnett, B. M. Monahan, K. Kirschbaum, W. P. Griffith, R. L. Whetten, U. Landman and T. P. Bigioni, Nature, 2013, 501, 399–402.
36. M. Bodiuzzaman, E. Khatun, K. S. Sugi, G. Paramasivam, W. A. Dar, S. Antharjanam and T. Pradeep, J. Phys. Chem. C, 2020, 124, 23426–23432.
37. L. Pen, P. Yuan, H. Su, S. Malola, S. Lin, Z. Tang, B. K. Teo, H. Häkkinen, L. Zheng and N. Zheng, J. Am. Chem. Soc., 2017, 139, 13288–13291.
38. G.-X. Duan, L. Tian, J.-B. Wen, L.-Y. Li, Y.-P. Xie and X. Lu, Nanoscale, 2018, 10, 18915–18919.
39. F. Hu, J.-J. Li, Z.-J. Guan, S.-F. Yuan and Q.-M. Wang, Angew. Chem., Int. Ed., 2020, 59, 5312–5315.
40. W. Fei, S. Antonello, T. Dainese, A. Dolmella, M. Lahtinen, K. Rissanen, A. Venzo and F. Maran, J. Am. Chem. Soc., 2019, 141, 16033–16045.
41. W.-Q. Shi, Z.-J. Kuan, J.-J. Li, X.-S. Han and Q.-M. Wang, Chem. Sci., 2022, 13, 5148–5154.
42. S. Hossain, D. Suzuki, T. Iwasa, R. Kaneko, T. Suzuki, S. Miyajima, Y. Iwamatsu, S. Pollitt, T. Kawawaki, N. Barrabés, G. Rupprechter and Y. Negishi, J. Phys. Chem. C, 2020, 124, 22304–22313.
43. W.-D. Tian, W.-D. Si, S. Havenridge, C. Zhang, Z. Wang, C. M. Aikens, C.-H. Tung and D. Sun, Sci. Bull., 2024, 69, 40–48.
44. C. A. Hosier and C. J. Ackerson, J. Am. Chem. Soc., 2019, 141, 309–314.
45. J. Xin, J. Xu, C. Zhu, Y. Tian, Q. Zhang, X. Kang and M. Zhu, Chem. Sci., 2023, 14, 8474–8482.
46. Y. Wang, Z. Liu, A. Mazumder, C. G. Gianopoulos, K. Kirschbaum, L. A. Peteanu and R. Jin, J. Am. Chem. Soc., 2023, 145, 26328–26338.
47. L. C. McKenzie, T. O. Zaikova and J. E. Hutchison, J. Am. Chem. Soc., 2014, 136, 13426–13435.
48. S. Biswas, S. Das and Y. Negishi, Coord. Chem. Rev., 2023, 492, 215255.
49. L. Li, Y. Zhu, B. Han, Q. Wang, L. Zheng, L. Feng, D. Sun and Z. Wang, Chem. Commun., 2022, 58, 9234–9237.
50. R. K. Gupta, L. Li, Z. Wang, B.-L. Han, L. Feng, Z.-Y. Gao, C.-H. Tung and D. Sun, Chem. Sci., 2023, 14, 1138–1144.
51. Y. Horita, S. Hossain, M. Ishimi, P. Zhao, M. Sera, T. Kawawaki, S. Takano, Y. Niihori, T. Nakamura, T. Tsukuda, M. Ehara and Y. Negishi, J. Am. Chem. Soc., 2023, 145, 23533–23540.
52. J.-J. Li, C.-Y. Liu, Z.-J. Guan, Z. Lei and Q.-M. Wang, Angew. Chem., Int. Ed., 2022, 61, e202201549.
53. E. Khatun, A. Ghosh, P. Chakraborty, P. Singh, M. Bodiuzzaman, P. Ganesan, G. Nataranjan, J. Ghosh, S. K. Pal and T. Pradeep, Nanoscale, 2018, 10, 20033–20042.
54. X. Kang, S. Wang and M. Zhu, Chem. Sci., 2018, 9, 3062–3068.
55. Y. Wang, Z. Liu, A. Mazumder, C. G. Gianopoulos, K. Kirschbaum, L. A. Peteanu and R. Jin, J. Am. Chem. Soc., 2023, 145, 26328–26338.
56. Z. Liu, Y. Li, E. Kahng, S. Xue, X. Du, S. Li and R. Jin, ACS Nano, 2022, 16, 18448–18458.
57. N. A. Sakthivel and A. Dass, Acc. Chem. Res., 2018, 51, 1774–1783.
58. X. Wei, Y. Lv, H. Shen, H. Li, X. Kang, H. Yu and M. Zhu, Aggregate, 2023, 4, e246.
59. Z. He, Y. Yang, J. Zou, Q. You, L. Feng, M.-B. Li and Z. Wu, Chem. – Eur. J., 2022, 28, e202200212.
60. S. Nakano, T. Yoshida, H. Taniguchi and M. Yasuki, Chem. Pharm. Bull., 1980, 28, 49–56.
61. D. Xi, M. Xiao, J. Cao, L. Zhao, N. Xu, S. Long, J. Fan, K. Shao, W. Sun, X. Yan and X. Peng, Adv. Mater., 2020, 32, 1907855.

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Footnote

† Electronic supplementary information (ESI) available: Fig. S1–S20 and Tables S1–S4 for experimental details, detailed crystallographic structures, PXRD, and UV-vis spectra. CCDC 2327808 and 2327952. For ESI and crystallographic data in CIF or other electronic format see DOI: https://doi.org/10.1039/d4nr01152j

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