Angewandte Eine Zeitschrift der Gesellschaft Deutscher Chemiker Chemie www.angewandte.de Akzeptierter Artikel Titel: Self-Assembly of Chiral Au Clusters into Crystalline Nanocubes of Exceptional Optical Activity Autoren: Lin Shi, Lingyun Zhu, Jun Guo, Lijuan Zhang, Yanan Shi, Yin Zhang, Ke Hou, Yonglong Zheng, Yanfei Zhu, Jiawei Lv, Shaoqin Liu, and Zhiyong Tang Dieser Beitrag wurde nach Begutachtung und Überarbeitung sofort als "akzeptierter Artikel" (Accepted Article; AA) publiziert und kann unter Angabe der unten stehenden Digitalobjekt-Identifizierungsnummer (DOI) zitiert werden. Die deutsche Übersetzung wird gemeinsam mit der endgültigen englischen Fassung erscheinen. Die endgültige englische Fassung (Version of Record) wird ehestmöglich nach dem Redigieren und einem Korrekturgang als Early-View-Beitrag erscheinen und kann sich naturgemäß von der AA-Fassung unterscheiden. Leser sollten daher die endgültige Fassung, sobald sie veröffentlicht ist, verwenden. Für die AA-Fassung trägt der Autor die alleinige Verantwortung. Zitierweise: Angew. Chem. Int. Ed. 10.1002/anie.201709827 Angew. Chem. 10.1002/ange.201709827 Link zur VoR: http://dx.doi.org/10.1002/anie.201709827 http://dx.doi.org/10.1002/ange.201709827 10.1002/ange.201709827 Angewandte Chemie COMMUNICATION Self-Assembly of Chiral Au Clusters into Crystalline Nanocubes of Exceptional Optical Activity Abstract: Self-assembly of inorganic nanoparticles into ordered structures is of paramount importance in both science and technology because of expected generation of new property through collective behavior; however, such nanoparticle assemblies with characteristics largely distinct from individual building blocks are hardly acquired so far. Here we use atomically precise Au clusters to fabricate ordered assemblies with emerging optical activity. Chiral Au clusters with strong circular dichroism (CD) but free of circularly polarized luminescence (CPL) are successfully synthesized and organized into uniform body-centred cubic (BCC) packing nanocubes. Once the ordered structure is formed, the CD intensity is significantly enhanced along with appearance of remarkable CPL response. Both experiment and theory calculation disclose that the CPL originates from restricted intramolecular rotation and ordered stacking pattern of chiral stabilizers, which are fastened in the crystalline lattices. Inorganic nanoparticle self-assembly not only offers a feasible route to realize possible application of nanomaterials in macro world, but also provides opportunity to produce new physiochemical properties beyond their individual building blocks through the collective behavior. Generally, the prerequisite of self-assembly is that both size and shape of the building blocks must be highly uniform. Such stringent requirement severely limits scale application of nanoparticles via self-assembly process, because different from molecular synthesis, to prepare monodisperse nanoparticles needs accurate control over nucleation and growth process that is time- and cost-consuming. Another great challenge in the field of nanoparticle assembly is that the reported assemblies seldom exhibit the emerging property or function greatly different from individual nanoparticles, and therefore the advantage of the ordered assemblies as well as the necessity of self-assembly fabrication are not highlighted. We expect that a specific type of nanoparticles, noble metal clusters with the size of less than 2 nm, would be excellent candidates for assembly building blocks. Thanks to their thermodynamic stability, varied types of noble metal clusters with magic number of composed atoms have been easily synthesized in a large quantity, allowing possible [a] [b] L. Shi, Prof. S. Liu School of Materials Science and Engineering, Center for Micro and Nanotechnology, Harbin Institute of Technology Harbin 150001 (P. R. China) E-mail: firstname.lastname@example.org L. Shi, Dr. L. Zhu, J. Guo, L. Zhang, Y. Shi, Y. Zhang, K. Hou, Y. Zheng, Y. Zhu, J. Lv, Prof. Z. Tang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 (P. R. China) E-mail: email@example.com Supporting information for this article is given via a link at the end of the document. construction of the assemblies at atomic level. However, until now there are very rare reports on self-assembly of noble metal clusters into ordered colloidal structures; and more importantly, no any new function is achieved with the assembled structures compared with individual building blocks though the clusters themselves possess many intriguing optical, electrical, magnetic and catalytic property. Herein, we target investigating self-assembly of chiral Au clusters mainly because of the following two reasons. (1) With respect to other nanoparticles, specific chirality could appear in Au clusters originating from organic ligand, surface staple or intrinsic Au atom arrangement, which gives rise to many additional unique features. (2) It is known that chirality and its corresponding property are highly sensitive to surrounding environment and spatial organization, so their assemblies might generate the novel property distinct from individual chiral clusters. Based on above idea, we attempt to design and synthesize the smallest chiral Au clusters, which optical activity is supposed to be easily influenced after self-assembly into the ordered structures. (R)- or (S)-2,2'-bis(di-p-tolylphosphino)-1,1'-binaphthyl, (R)or (S)-Tol-BINAP, was adopted as chiral ligands to synthesize Au clusters (Supporting Information part 1.2). The single crystal X-ray diffraction (SC-XRD) analysis reveals that the products are Au3[(R)-Tol-BINAP]3Cl and Au3[(S)-Tol-BINAP]3Cl clusters, respectively (Table S1 and S2), and as-formed crystal structure of both Au3[(R)-Tol-BINAP]3Cl and Au3[(S)-TolBINAP]3Cl clusters belongs to a cubic space group, I213, which is chiral. In detail, three Au atoms in one cluster connect with each other and form a regular triangle, in which the Au-Au bond lengths are 2.676(2) Å (Figure 1 and Figure S1b). These Au-Au bond lengths are well in the reported range of 2.572(2)-3.216(2) Å, suggesting presence of the attractive aurophilic interaction inside chiral Au clusters. In addition, each Au atom binds with a chiral bi-phosphine ligand through the P-Au-P bond with unequal bond length of 2.380(7) Å and 2.397(8) Å. By simply changing the chirality of ligand from R to S during synthesis, one can easily achieve the cluster of opposite chirality (Figure 1). Figure 1. Au3[(R)-Tol-BINAP]3Cl (a) and Au3[(S)-Tol-BINAP]3Cl (b) (Au, yellow; P, orange; C, gray; for clarity, hydrogen and counter anion chloride are omitted). The surface aromatic ligands arrange in either left-handed or righthanded stacking when viewed perpendicularly to Au3 plane. This article is protected by copyright. All rights reserved. Accepted Manuscript Lin Shi[a], [b], Lingyun Zhu[b], Jun Guo[b], Lijuan Zhang[b], Yanan Shi[b], Yin Zhang[b], Ke Hou[b], Yonglong Zheng[b], Yanfei Zhu[b], Jiawei Lv[b], Shaoqin Liu*[a], Zhiyong Tang*[b] 10.1002/ange.201709827 Angewandte Chemie The molecular formula of Au3[(R)-Tol-BINAP]3Cl cluster was further verified by electrospray ionization mass spectrometry (ESI-MS). Figure S2a shows an isotopically resolved peak at m/z = 2626.71987 with a +1 charge, corresponding to a species of the cluster minus one Cl- (calcd: 2626.68411 in Figure S2b). As for the Au3 core, its charge state is determined by measuring the bonding energy of Au4f7/2 via Xray photoelectron spectroscopy (XPS). The fitting result manifests that all the Au atoms in the cluster are same, characteristic with the bonding energy of Au 4f7/2 at 84.4 eV and Au 4f5/2 at 88.1 eV that locates in the middle of Au (0) and Au (I) (Figure S3). In regard of the surrounding chiral ligand, its six aromatic rings can be divided into three groups based on the crystal structure (Figure 1): two outward naphthalene rings (yellow double hexagons), two outward p-tolyl rings (yellow hexagons) and two inward p-tolyl rings (red hexagon and hollow hexagon). These aromatic rings form left- or right-handed stacking on the surface of Au clusters based on the chirality of ligands (Figure 1), endowing the capability to produce the strong optical activity of Au clusters. hexane increasing (Figure 2b), resulting from formation of strong intermolecular interactions among chiral ligands upon cluster assembly. In detail, the negative CD peak at 239 nm red shifts to 256 nm, and the original positive peak at 267 nm becomes weak and finally disappears; while the negative peak at 288 nm decreases and red shifts, accompanying with formation of new negative peaks at 325 nm and 355 nm (Figure 2b). Most importantly, the positive peak at around 366 nm of the maximum gabs factor gradually diminishes and finally disappears (black arrow in Figure 2b), whereas a new positive peak progressively appears at 445 nm and enhances with the fraction of n-hexane increasing (red arrow in Figure 2b).The maximum gabs value at 445 nm is up to 8.6 x 10-3 in 70% n-hexane (Figure S5b). When the fraction of n-hexane exceeds 70%, the mixed solvent becomes turbid and UV-Vis absorption intensity increases substantially (Figure 3c), implying that large-sized aggregates with strong light scattering are produced with too much antisolvent (Figure S6). As a result, the maximum gabs factor is decreased (4.5 x 10-3 for 80% n-hexane and 4.0 x 10-3 for 90% n-hexane, respectively) (Figure 2c, d). Figure 2. a, CD spectra of Au3[(R)-Tol-BINAP]3Cl and Au3[(S)-Tol-BINAP]3Cl clusters in DCM. b-d, CD spectra (b), UV-Vis spectra (c) and corresponding gabs factor (d) of Au3[(R)-Tol-BINAP]3Cl clusters in DCM with various n-hexane content (cluster concentration: 5 x 10-5 M; optical path length: 1 mm). Figure 3. a, PL spectra of Au3[(R)-Tol-BINAP]3Cl clusters in DCM with various n-hexane content (inserts present digital photos of samples with 0 or 70% nhexane under irradiation of 365 nm UV light). b, Relative PL intensity against composition of the mixed solvent. c, d, CPL spectra (c) and corresponding glum factor (d) of Au3[(R)-Tol-BINAP]3Cl (blue curve) and Au3[(S)-Tol-BINAP]3Cl (red curve) assemblies in 70% n-hexane. The dashed fluctuations in (c) are the original collected data, while the solid curves are the smoothed ones (cluster concentration: 5 x 10-5 M; optical path length: 1 mm). The enantiomers of Au clusters that are well dispersed in dichloromethane (DCM) exhibit intense CD response with an excellent mirror image in the wavelength range of 220 nm - 500 nm (Figure 2a), and thus we select Au3[(R)-Tol-BINAP]3Cl clusters as the representative for following study. The CD spectrum of Au3[(R)-Tol-BINAP]3Cl possesses four distinct peaks at 239 nm, 267 nm, 288 nm and 366 nm, respectively, which is largely different with CD feature of pure chiral ligands (Figure S4). Impressively, the maximum absorption anisotropy factor (gabs factor) reaches 7.0 x 10-3 at 366 nm (Figure S5a), which is record high among the reported noble metal clusters (Table S3). Subsequent self-assembly of chiral Au clusters in polar DCM was easily implemented through adding non-polar nhexane as antisolvent. Evidently, all the CD peaks show gradual bathochromic shift and become broadened with the fraction of n- A striking discovery in optical property is that upon selfassembly, the non-luminescent Au clusters progressively become highly luminescent (Figure 3a and Figure S6). An orange emission band centered at 583 nm appears for Au3[(R)Tol-BINAP]3Cl clusters when the fraction of n-hexane is increased to 40%, and displays further enhancement with increase of n-hexane fraction. When the fraction value of nhexane gets to 70%, the photoluminescence (PL) intensity reaches the highest value with a quantum yield (QY) of 3.6% (calibrated with luminescent Rhodamine 6G) (Figure 3b). The PL intensity shows obvious decrease when the fraction value of nhexane exceeds 70%, likely due to formation of large-sized This article is protected by copyright. All rights reserved. Accepted Manuscript COMMUNICATION 10.1002/ange.201709827 Angewandte Chemie aggregates with poor crystallinity. The similar change is found by analyzing their PL decay profiles. The dominant PL decay time also follows the order: 50% n-hexane (0.59 μs) 60% nhexane (0.69 μs) 70% n-hexane (0.79 μs) 80% n-hexane (0.75 μs) 90% n-hexane (0.68 μs) (Figure S7). The microsecond PL decay time and the large Stokes shift of ~138 nm clearly suggest that the luminescence of clusters originates from a triplet parentage, which is assigned to a triplet ligand-tometal charge transfer (3LMCT) excited state or a triplet ligand-tometal-metal charge transfer (3LMMCT) excited state. It needs to be stressed that based on the facts of 2.676(2) Å Au-Au bond length and the mixed-valence of Au (0/I), the attractive aurophilic interaction should considerably contribute to the PL property of chiral Au clusters. More intriguingly, these chiral Au cluster assemblies show strong CPL response in the same wavelength region as their PL peak centered at 583 nm (Figure 3c). It is noted that the luminescence anisotropy factor (glum factor), remains zero when the fraction of n-hexane is less than 40%, followed by dramatic increase and subsequent slight decrease with gradual increase of n-hexane content (Figures S8 and S9). The maximum glum factor of about ± 7 x 10-3 is acquired in 70% n-hexane (Figure 3d). Figure 4. a, Scanning electron microscope (SEM) image of Au3[(R)-TolBINAP]3Cl cluster assemblies in DCM with 70% n-hexane. The insert is side view of a nanocube. b, PXRD pattern of Au3[(R)-Tol-BINAP]3Cl cluster assemblies (black curve) and simulated pattern according to the crystal structure (red lines). c, d, TEM image (c) and corresponding SAED patterns (d) of self-assembled nanocubes. What is the reason responsible for the significant change in both CD and CPL activity upon tuning n-hexane fraction in the mixture solvent? To answer this question, we firstly characterized the morphology and structure of as-assembled products. As revealed by dynamic light scattering (DLS) measurement, Au3[(R)-Tol-BINAP]3Cl clusters are well dispersed in the solvent with n-hexane fraction of less than 40%; whereas the cluster aggregates appear when n-hexane fraction exceeds 40% and their sizes gradually grow from hundred nanometers to several micrometers along with increase of poor solvent fraction (Figure S10). Transmission electron microscopy (TEM) imaging and corresponding selected area electron diffraction (SAED) survey further indicate that the cluster aggregates are irregular and amorphous when the fraction of n-hexane is less than 60%, while well-defined nanocubes of sharp edges start to appear in the mixed solvent of 60% hexane (Figure S11). Significantly, cluster assemblies become very uniform when the fraction of nhexane reaches 70%, which exhibit a cubic morphology with an average edge length of 366 nm (Figure 4a, c and Figure S12). With further increase of the fraction of n-hexane, the grain sizes of Au cluster aggregates instead decrease and their shapes turn to be disparity (Figure S13), which are caused by too quick aggregation of Au clusters in poor solvent. We then focused the structure investigation on uniform nanocubes obtained in 70% hexane (Figure 4). Notably, all the diffraction peaks in powder X-ray diffraction (PXRD) curve of nanocubes are well assigned to the simulated BCC packing pattern based on the single crystal structure of Au3[(R)-Tol-BINAP]3Cl clusters (Figure 4b). Such an ordered BCC packing structure is also verified by SAED observation on single nanocube (Figure 4c, d), where sharp diffraction spots corresponding to (-200) and (020) reflections are clearly discerned along  direction. The calculated interplanar spacing along (-200) from SAED (1.41 nm) is very close to the value acquired by SC-XRD (1.44 nm), which further confirms the crystalline BCC packing pattern inside nanocubes. To understand the influence of cluster assembly on the optical activity, theory calculation on individual cluster was firstly carried out. It deserves mentioning that the simulated UV-Vis absorption and CD spectra of the enantiomers match very well with the measured ones regardless of the peak sign or the peak position, demonstrating the validity of our calculation (Figure S14a). The HOMO of Au3[(R)-Tol-BINAP]3Cl and Au3[(S)-TolBINAP]3Cl clusters mainly lies on the Au and P atoms, while the transition-related doubly degenerate LUMO and LUMO+1 mostly locate on the naphthalene rings of (R)- or (S)-Tol-BINAP ligands (Figure S14b). All the excited states are composed by metal-toligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT), so the conformation of chiral ligands on Au cluster surfaces is crucial in determining their optical activity (for detailed analysis, see Figure S14-S25). The extremely enhanced optical activity via self-assembly of the chiral Au clusters can be understood based on crystal structure analysis. In the nanocube with the ordered chiral I213 packing structure, each Au cluster contacted with six nearby Au clusters, which are divided into two groups as the cluster assembly possesses a local chiral C3 symmetry (Supporting Movie). Three adjacent Au clusters form CH/π interactions with the central one via both outward naphthalene ring pairs (Figure S26) and the inward p-tolyl ring pairs (Figure S27). Meanwhile, the other three adjacent Au clusters form CH/π interactions with the central one through an outward naphthalene rings and an inward p-tolyl rings (Figure S28). Note that the attraction energy of the CH/π interactions is in the range of -1.5 to -2.5 kcal/mol, which is much larger than the molecular thermal energy at room temperature (0.57 kcal/mol). Once the Au clusters are This article is protected by copyright. All rights reserved. Accepted Manuscript COMMUNICATION 10.1002/ange.201709827 Angewandte Chemie COMMUNICATION Acknowledgements The authors acknowledge financial support from National Key Basic Research Program of China (2014CB931801 and 2016YFA0200700, Z.Y.T.), National Natural Science Foundation of China (21475029 and 91427302, Z.Y.T.), Frontier Science Key Project of the Chinese Academy of Sciences (QYZDJ-SSWSLH038, Z.Y.T.), Instrument Developing Project of the Chinese Academy of Sciences (YZ201311, Z.Y.T.), CAS-CSIRO Cooperative Research Program (GJHZ1503, Z.Y.T.), "Strategic Priority Research Program" of Chinese Academy of Sciences (XDA09040100, Z.Y.T.) and K.C.Wong Education Foundation. Keywords: self-assembly • gold • nanocluster • chirality • circularly polarized luminescence  a) T. Wang, J. Zhuang, J. Lynch, O. Chen, Z. Wang, X. Wang, D. LaMontagne, H. Wu, Z. Wang, Y. C. Cao, Science 2012, 338, 358-363; b) C. R. Kagan, C. B. Murray, Nat. Nanotech. 2015, 10, 1013-1026; c) J.-H. Choi, H. Wang, S. J. Oh, T. Paik, P. Sung, J. Sung, X. Ye, T. Zhao, B. T. Diroll, C. B. Murray, C. R. Kagan, Science 2016, 352, 205-208; d) M. A. Boles, M. Engel, D. V. Talapin, Chem. Rev. 2016, 116, 11220-11289; e) T. Chen, S. Yang, J. Chai, Y. Song, J. Fan, B. Rao, H. Sheng, H. Yu, M. Zhu, Science Advances 2017, 3, e1700956; f) L. Ai, W. Jiang, Z. Liu, J. Liu, Y. Gao, H. Zou, Z. Wu, Z. Wang, Y. Liu, H. Zhang, B. Yang, Nanoscale 2017, 9, 12618-12627.  a) P. F. Damasceno, M. Engel, S. C. Glotzer, Science 2012, 337, 453-457; b) G. Singh, H. Chan, A. Baskin, E. Gelman, N. Repnin, P. Král, R. Klajn, Science 2014, 345, 1149-1153;  D. V. Talapin, E. V. Shevchenko, M. I. Bodnarchuk, X. Ye, J. Chen, C. B. Murray, Nature 2009, 461, 964-967.  H. Qian, M. Zhu, Z. Wu, R. Jin, Acc. Chem. Res. 2012, 45, 1470-1479.  a) R. Jin, C. Zeng, M. Zhou, Y. Chen, Chem. Rev. 2016, 116, 1034610413; b) C. Zeng, Y. Chen, K. Kirschbaum, K. J. Lambright, R. Jin, Science 2016, 354, 1580-1584.  Nonappa, T. Lahtinen, J. S. Haataja, T.-R. Tero, H. Häkkinen, O. Ikkala, Angew. Chem. Int. Ed. 2016, 55, 16035-16038; Angew. Chem. 2016, 128, 16269-16272.  S. Knoppe, T. Burgi, Acc. Chem. Res. 2014, 47, 1318-1326.  C. Zeng, T. Li, A. Das, N. L. Rosi, R. Jin, J. Am. Chem. Soc. 2013, 135, 10011-10013.  Y. Yanagimoto, Y. Negishi, H. Fujihara, T. Tsukuda, J. Phys. Chem. B 2006, 110, 11611-11614.  CCDC 1491313 (Au3[(R)-Tol-BINAP]3Cl), 1491314 (Au3[(S)-TolBINAP]3Cl) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via http://www.ccdc.cam.ac.uk/data_request/cif.  H. Schmidbaur, A. Schier, Chem. Soc. Rev. 2012, 41, 370-412. Z. Y. Bao, W. Zhang, Y.-L. Zhang, J. He, J. Dai, C.-T. Yeung, G.-L. Law, D. Y. Lei, Angew. Chem. Int. Ed. 2017, 56, 1283-1288; Angew. Chem. 2017, 129, 1303-1308.  C. Po, A. Y.-Y. Tam, K. M.-C. Wong, V. W.-W. Yam, J. Am. Chem. Soc. 2011, 133, 12136-12143.  Y. Dong, J. W. Y. Lam, A. Qin, Z. Li, J. Sun, H. H. Y. Sung, I. D. Williams, B. Z. Tang, Chem. Commun. 2007, 0, 40-42.  L.-Y. Yao, F. K.-W. Hau, V. W.-W. Yam, J. Am. Chem. Soc. 2014, 136, 10801-10806.  V. W.-W. Yam, V. K.-M. Au, S. Y.-L. Leung, Chem. Rev. 2015, 115, 75897728.  B. Ni, H. Liu, P.-p. Wang, J. He, X. Wang, Nat. Commun. 2015, 6, 8756.  S. Tsuzuki, K. Honda, T. Uchimaru, M. Mikami, K. Tanabe, J. Am. Chem. Soc. 2002, 124, 104-112.  J. Mei, N. L. C. Leung, R. T. K. Kwok, J. W. Y. Lam, B. Z. Tang, Chem. Rev. 2015, 115, 11718-11940.  K. Pyo, V. D. Thanthirige, K. Kwak, P. Pandurangan, G. Ramakrishna, D. Lee, J. Am. Chem. Soc. 2015, 137, 8244-8250. This article is protected by copyright. All rights reserved. Accepted Manuscript assembled, the strong intermolecular CH/π interactions would largely restrict the intramolecular rotation of the inward p-tolyl rings, which is confirmed by temperature- or concentrationdependent 1H nuclear magnetic resonance (NMR) spectroscopy (Figures S29-S33). Subsequently, ordered left- or right-handed stacking patterns are formed on the surface of R/S-Au3 clusters (red arrows in Figure 1,), which are responsible for enhancement of CD intensity. Such strong intermolecular CH/π interactions between chiral ligands further result in red shift of the peaks in both UV-Vis absorption and CD spectra (Figure 3b and 3c), which is reasonable considering that all the peaks originating from MLCT or LLCT process are largely contributed by chiral ligands (Figure 5 and Tables S4 and S5). More importantly, the restricted intramolecular rotation of inward ptolyl rings efficiently blocks the non-radiative relaxation channel of the excited state and populates its radiative decay pathway, which finally facilitates generation of PL and CPL responses from 3LMCT or 3LMMCT excited state. The corresponding luminescence mechanism is as follows: the singlet state formed via MLCT or LLCT process relaxes to triplet state through fast intersystem crossing with aid of the large spin-orbit coupling of heavy gold atoms, followed by PL and CPL generation via 3 LMCT or 3LMMCT process. Noteworthily, as for the exceptional case of nanocubes with ordered BCC packing structure (Figure 4), every inward p-tolyl rings on the Au cluster surfaces are fully fixed via intermolecular CH/π interactions, and thus both PL intensity and glum factor reach the highest values (Figure 3a and 3b). In summary, chiral Au3 clusters of the smallest size and the record-high optical absorption activity have been successfully synthesized and used as building blocks for spontaneous organization into nanocubes of well-defined BCC arrangement. Thanks to the strong intermolecular CH/π interactions, the rotation of chiral ligands are drastically restricted, and therefore the optical absorption activity of as-assembled products is redshifted and further enhanced. More excitingly, distinct from individual clusters free of luminescence, the chiral Au cluster assemblies become highly emissive and the strongest CPL response is acquired with the ordered structure. It is highly expected that design and application of clusters, which possess accurate atomic structure and specific optical, magnetic or catalytic property, will open the new era in the self-assembly field beyond conventional molecules and nanoparticles. 10.1002/ange.201709827 Angewandte Chemie COMMUNICATION Lin Shi, Lingyun Zhu, Jun Guo, Lijuan Zhang, Yanan Shi, Yin Zhang, Ke Hou, Yonglong Zheng, Yanfei Zhu, Jiawei Lv, Shaoqin Liu*, Zhiyong Tang* Page No. – Page No. Self-Assembly of Chiral Au Clusters into Crystalline Nanocubes of Exceptional Optical Activity Accepted Manuscript Chiral Au3 clusters that possess the remarkable CD anisotropy factor are successfully synthesized. This CD anisotropy factor is further enhanced upon cluster self-assembly. Distinct from individual clusters free of luminescence, the chiral Au cluster assemblies become highly emissive and the strongest CPL activity is achieved with the ordered bodycentred cubic structure. This article is protected by copyright. All rights reserved.