Assembly and Induction of Circularly Polarized Luminescence from

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Real-Time Monitoring of Hierarchical Self-Assembly and Induction of Circularly Polarized Luminescence from Achiral Luminogens Jing Zhang, Qiuming Liu, Wenjie Wu, Junhui Peng, Haoke Zhang, Fengyan Song, Benzhao He, Xiaoyan Wang, Herman H.-Y. Sung, Ming Chen, Bing Shi Li, Sheng-Hua Liu, Jacky W. Y. Lam, and Ben Zhong Tang ACS Nano, Just Accepted Manuscript • Publication Date (Web): 05 Mar 2019 Downloaded from http://pubs.acs.org on March 5, 2019

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Real-Time

Monitoring

of

Hierarchical

Self-

Assembly and Induction of Circularly Polarized Luminescence from Achiral Luminogens Jing Zhang,†,# Qiuming Liu,

Wenjie Wu,†,# Junhui Peng,† Haoke Zhang,† Fengyan Song,†

Benzhao He,† Xiaoyan Wang,§ Herman H.-Y. Sung,† Ming Chen,† Bing Shi Li,*,‡ Sheng Hua Liu,§ Jacky W. Y. Lam,† and Ben Zhong Tang*,†, †

Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research

Center for Tissue Restoration and Reconstruction, Institute for Advanced Study, and Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China ‡

College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060,

China §

Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of

Chemistry, Central China Normal University, Wuhan 430079, China Center for Aggregation-Induced Emission, SCUT-HKUST Joint Research Institute, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China

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whom correspondence should be addressed: [email protected] (B. S. Li);

[email protected] (B. Z. Tang)

ABSTRACT: Constructing artificial helical structures through hierarchical self-assembly and exploring the underlying mechanism are important, and they help to get insight from the structures, processes and functions from the biological helices and facilitate the development of material science and nanotechnology. Herein, the two enantiomers of chiral Au(I) complexes (S)-1 and (R)1 were synthesized and they exhibited impressive spontaneous hierarchical self-assembly transitions from vesicles to helical fibers. An impressive chirality inversion and amplification was accompanied with the assembly transition, as elucidated by the results of in situ and timedependent circular dichroism spectroscopy and scanning electron microscope imaging. The two enantiomers could serve as ideal chiral templates to co-assemble with other achiral luminogens to efficiently induce the resulting co-assembly systems to show circularly polarized luminescence (CPL). Our work has provided a simple but efficient way to explore the sophisticated self-assembly process and presented a facile and effective strategy to fabricate architectures with CPL properties.

KEYWORDS: aggregation-induced emission, gold complex, real-time monitoring, hierarchical self-assembly, circularly polarized luminescence


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Hierarchical self-assembly is ubiquitous in nature and it is one of the most sophisticated bottom– up approach used by living organisms to construct desirable architectures using molecular building blocks.1-8 Compared with the nonhierarchical self-assembled systems, biological systems with structural integrity originating from hierarchical self-assemblies are far superior. They exhibit higher stability against environmental changes (e.g. pH, temperature, and pressure) and much greater strength against external stimuli (e.g. mechanical, electric, or magnetic force).2 Because of these advantages, the strategy of hierarchical self-assembly has also been widely used to accomplish the construction of functional materials at nanoscale and microscale that have the applications in various fields ranging from optoelectronic materials to biomedicine.9-17 Therefore, in-depth exploration of the hierarchical self-assembly processes and the underlying mechanism are vital to mimic or even surpass nature’s designs and meet the real-life application. Chirality, as an important biochemical symbol of life, is omnipresent in nature and plays a crucial role in the hierarchical construction of living systems. Helicity, as the central structural motif in living hierarchical systems, is a consequence of hierarchical self-assembly constructed from chiral subunits such as amino acids. Through a hierarchical self-assembly approach, natural system is able to express and amplify molecular chirality into preferred supramolecular helicity (e.g., secondary alpha-helix structures of peptides and proteins) so as to perform various physiological functions. The precisely controllable scale and chirality sign are of great importance since they are closely related to diverse physiological functions in nature (e.g., recognition, catalytic activity, gene replication and expression).18-29 Therefore, insight into the underlying mechanisms of the hierarchical assemblies is a fundamental and important issue not only in modern biology but in material science and nanotechnology as well.30-32


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Nevertheless, it remains an incredibly paramount challenge to thoroughly decipher the hierarchical self-assembly process due to the involved complexity. Advanced microscopy technologies, including scanning force microscopy (SFM), scanning electron microscope (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), etc., can reveal a transitory morphology of the self-assembled morphologies at a specific stage of the self-assembly, but cannot reveal the whole assembly process. It has been well-established that optical spectrometer is a powerful technique on account of the extreme sensitivity of the I

J

chromophore to conformational, orientational, and supramolecular states.33,34 CD signals originate from the electronic transitions of the chromophore and are highly sensitive to the molecular conformations as well as the molecular aggregation.35,36 Therefore, CD spectrometer has been employed as one of the most important techniques for probing chirality variations in molecular, nano-assembles,

biological

macromolecular

and

supramolecular

systems.

Amongst,

supramolecular helical systems generated from hierarchical assemblies is fully adaptable to the outstanding sensitivity of CD method, because chirality is usually significantly amplified in the progress of helical growth, which in turn facilitates CD detection.37-39 However, the realization of in situ and real-time monitoring for hierarchical self-assembly process by utilizing CD method is relatively rarely reported. As important as the chirality,

K

interactions such as aurophilic interactions are also

pivotal to precisely control the formation of distinct artificial helical architectures, especially those closely related to biological processes.40-50 In this work, by hybridizing chirality with aurophilic interactions in molecules, we have developed a chiral Au(I) system containing two enantiomers (S)-1 and (R)-1 featuring aggregation-induced emission (AIE) property, respectively (Scheme 1). The present chiral systems were found to undergo hierarchical self-assembly processes to form


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diverse well-defined architectures at each specific aggregate state. We monitored the real-time hierarchical architecture processes of molecules by CD spectroscopy, which were characterized with an impressive chirality inversion and amplification; meanwhile we also captured the transitory morphologies from vesicles to helical fibers which were formed on the corresponding stages of the assembly process by utilizing SEM and AFM imaging (Scheme 2). It is appealing that this chiral Au(I) system with highly-ordered helical organization is also an ideal chiral template to obtain desired circular polarized luminescence (CPL).51-56 In this work, by combining the chiral Au(I) system with different types of luminogens,57-59 we constructed a series of two-component co-assembly systems by employing a role-sharing and complementary strategy; the chiral Au complexes (S)-1 and (R)-1 were used as chiral templates and the added luminogens were selected to act as acceptors. The resulting co-assembly systems have successfully applied to CPL induction (Scheme 2). CPL is a highly sensitive and powerful tool for evaluating the excitedstate information of chiral luminescence system, and related studies have aroused considerable attention in recent years due to their fundamental importance and wide application potential in photo-technology and biosensor.60-67 However, the achievement of nano/micro architectures with suitable CPL performances are still a challenging task. We envisage that this template-directed CPL induction method may provide a facile and effective strategy to fabricate CPL-active materials.


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The target Au(I) complexes (S)-1 and (R)-1 were readily prepared along the synthetic route presented in Scheme S1 in the Supporting information. All the intermediates and desirable products were characterized by NMR and high-resolution mass spectroscopies with satisfactory results and specific details have been provide in the Supporting Information (Figures S1-S14). Both enantiomers possess very high chiral purity (enantiomeric excess (ee) value > 99%, Figure S15). Additionally, the molecular structures of complexes (S)-1 and (R)-1 have been further resolved by single crystal X-ray diffraction (details see below) and the associated data were collected in Table S1. Complexes (S)-1 and (R)-1 exhibited typical AIE properties,57,68,69 as evidenced by their respective photoluminescence (PL) spectra measured in the pure THF solution and aggregate states (Figure 1, Figures S16 and S17). Initially, their PL intensities are nearly zero with no any emission in the mixtures of water fraction (fw, vol %) less than 70%. When the water contents increased to 70% and 80%, weak orange emission bands centered at 560 nm appeared. Furthermore, the newly appeared emission were dramatically enhanced with the increase of water fraction to 90% and ultimately reached their maximum with 99% water. In light of the chiral nature of these two complexes, CD experiments were further performed to study the chirality of their aggregate states. As shown in Figure S18, the CD spectra of (S)-1 and (R)-1 display intense Cotton effects and a mirror-image relationship at the wavelength of F--K5-nm. Compared with pure THF solution, the CD bands and the corresponding absorption bands located at around 260 nm and 300 nm of a series of aggregate states, exhibited distinct difference (Figure S18), indicating that the chirality of the present enantiomers are sensitive to the change of the surrounding solvent environment.


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Figure 1. (A) PL spectra of complexes (S)-1 and (R)-1 in THF/water mixtures, /ex = 335 nm. Concentration: 5.0 × 10-5 M. (B) Plot of relative emission peak intensity (0AIE) at 560 nm versus fw of the THF/water mixtures, where 0AIE = I/I0, I = emission intensity and I0 = emission intensity in THF solution. Inset: photos taken under 365 nm UV. Amazingly, the freshly prepared mixtures containing 80% water (THF/water, 1/4, v/v) of complexes (S)-1 and (R)-1 were clear, but became turbid after one hour of aging, indicative of the formation of large aggregates with strong light scattering. It could be reasonably envisaged that appropriate self-assembly processes might occur in the THF/water (1/4, v/v) mixture. The challenge in exploring the self-assembly process is how to reveal all the transitional stages in the assembly.33 At this point, the highly sensitive CD spectrometer can monitor a continuous transition of the helical assemblies.35,36,70-72 We then conducted an in situ and time-dependent CD monitoring of the dynamic transition of the chiral nanostructures in the above critical THF/water (1/4, v/v) systems. Complex (R)-1 (1 × 10-4 M) was picked out as the representative for the following elaboration (Figure 2 and Figure S19).


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As shown in Figure 2A, the CD curve of the freshly prepared THF/water (1/4, v/v) mixture showed a weak positive signal at the wavelength of ~300 nm and two relatively strong signals at the wavelength of ~250 nm and 230 nm, respectively, which are attributed to absorption of the chiral binaphthyl moieties.66,72-74 The broad peak at the wavelength of 300 nm began to decrease at prolonged incubation time, and became reversed after 3 h of incubation time. After incubation for 144 h, the peak exhibited the highest negative signal with an impressive molar ellipticity ([4]) of 440000 deg cm2 dmol-1. A similar inversion of the absorption was observed for the peak at the wavelength of ~250 nm. But its corresponding absorption spectra remained unchanged (Figure 2B). The plot of [4] versus time in Figure 2C showed a much more intuitive picture of the above inversions. While the band at the wavelength of 210 nm showed only a monotonous enhancement at prolonged incubation time, which in turn indicates that the varying signals located at ~250 and 300 nm contain much more induced components originated from self-assembly process. The CD profile of enantiomer (S)-1 exhibited almost a mirror reversion with that of (R)-1 (Figure 2D), while its absorption also showed no any obvious changes (Figure S19), further implying that the dynamic self-assembly exerts a significant impact on their CD signals. Herein, the results of the above in situ CD monitoring preliminarily verified our hypothesis that the molecules have undergone multiple morphological transitions before forming the steady self-assembly. This morphological transitional process is very slow and it undergoes at the time scale of hours, which offers the possibility to monitor the morphological transition.


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Figure 2. The time-dependent CD (A) and UV (B) spectra, and plots (C) of [4] versus time of complex (R)-1 measured in THF/water (1/4, v/v) mixture. (D) CD spectra of complexes (S)-1 and (R)-1 measured in THF/water (1/4, v/v) mixtures (dash line: fresh mixtures; solid line: mixtures stored for 144 h; inset: amplification of their fresh states). Concentration: 1 × 10-4 M. [4] = molar ellipticity.


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Visual confirmation of the nanostructures formed at the specific stage were then garnered from microscopic imaging.35 As expected, further time-dependent morphological changes of (R)-1 observed directly by SEM, AFM and transmission electron microscopy (TEM) unambiguously proved our proposed self-assembly processes. As shown in Figure 3A, Figures S20 and S21, vesicles were formed upon aggregation in the freshly prepared THF/water mixtures, and their average diameters decreased with the increase of water fractions consistent with the DLS data (Figure S22). It’s well-known that the formation of vesicles is a complicated process. Regarding our present THF/water mixture, we proposed that these two chiral enantiomers are more likely to self-assemble into spherical micelles first and then evolved into hollow vesicles upon entry of water molecules.75 According to their molecular structures, we presumed that the hydrophilic pentafluorophenyl groups formed the interior and exterior coronas, while the more hydrophobic binaphthyl group probably became the membrane of the vesicles. Additionally, there exist multiple intra- and intermolecular weak interactions as well as weak aurophilic interactions (vide infra) to assist the formation of membranes.75 To better unveil the reason for the chiral inversion and amplification observed in CD spectra, we also conducted the morphological monitoring of the selfassembled structures by SEM at different time intervals of the incubation of the six days. As shown in Figure 3A and Figure S23, the vesicles began to coalesce one-by-one and formed the “necklace”-like morphology after one hour of incubation. And the above “necklaces” gradually grew into loosely twisted helical ribbons or fibers with the axial elongation and fusion after 6 h. After three days, compactly twisted helical fibers with the helical pitch of ~300 nm ((S)-1) and ~400 nm ((R)-1) formed, where spirals could be clearly observed (Figure 3A, Figures S23-S26). In addition, the helical fibers formed by (S)-1 are uniformly right-handed (P) (Figure 3B), while the helical nanofibers formed by (R)-1 are all left-handed (M) (Figure 3C), i.e., the handedness of


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helixes formed by the two enantiomer are perfectly opposite, which further verifies that their mirror CD signals observed in this stage are dominated by the opposite helical superamolecuar chirality. It should be mentioned that the CD signal we detected actually reflects statistical information of excessive handedness of all levels of chiral molecular architectures, including single molecular chirality and supramolecular assemblies as well.59 Herein, the morphological transition process can be patched up based on these images, which helps rationalize the timedependent variation in CD signal: 1) For the freshly prepared THF/water mixture, the chiral signals originated from the molecular chirality, mainly associated with the chiral binaphthyl moieties. 2) In the following three hours, due to the fusion of vesicle aggregates and further formation of loosely twisted ribbons, the chirality generating from the newly-formed self-assembly system is opposite to the molecular chirality to result in the annihilation of the original CD signal. 3) Subsequently, the formation of compact helix gradually dominates the chiral environment and the overall supramolecular chirality ultimately supersedes the molecular chirality. And the opposite handedness of helical fibers renders the CD signal completely inverse. 4) In the final stage, much longer helical fibers with micrometer scale (Figure S27) ultimately formed over six days and orange fibers can be clearly observed under fluorescence microscopy (FLM) (Figure S28). Concomitantly, the supramolecular chirality is further significantly amplified, well consistent with the significant increase in CD signal. It should be mentioned that we also noted that the helices of (S)-1 are relatively more compact and their helical pitches are smaller than those of (R)-1 formed at the same time intervals (S)-1): ~300 nm; (R)-1: ~400 nm as shown in Figures S25 and S26). Herein, we presume that the different degrees of amplification in CD signals of the two enantiomers observed in Figure 2D, especially the signals significantly influenced by the selfassembly processes at ~250-300 region, should be mainly associated with these distinct helical


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conformations.76,77 Accordingly, our results further confirm the dynamic self-assembly effect and the vital role of supramolecular helical structures in determining the CD signal.78 Similarly, for bio-mimetic self-assembly, in most cases, their molecular chirality is also transferred to their selfassembled aggregates through hierarchical approach, which ensures a very efficient outcome for the generation of highly functional self-assembled structures.2 Our findings may provide an important perspective for mimicking biological hierarchical self-assembly process or developing bioinspired helical systems. As we know, hierarchical self-assembly is a subtle process, which is sensitive to the changes on the environmental conditions. We also carried out systematic research on the THF/water systems with different water fractions with time, however we didn’t observe any similar hierarchical selfassembly, chiral inversion or amplification (Figure S29). Therefore, a volume ratio of THF/water of 1/4 is critical for the transition and formation of the observed self-assembly, which provides suitable driving force for the formation of hierarchical self-assembly. To further get insight into the driving force of their hierarchical self-assembly, we also obtained the crystals of both enantiomers by layering hexane as a poor solvent on top their respective dichloromethane solution. Detailed crystallographic data have been collected in Table S1. As illustrated in Figure 4A and 4B, there exist multiple intra- and intermolecular IKI contacts (3.6~3.8 Å) between two paralleled aromatic rings in the crystal structures of (S)-1 and (R)-1, which are connected via weak aurophilic interactions with gold-gold distances of 3.6~3.8 Å and CH F interactions of 2.7 Å. In addition, perfect helical arrangements formed via the head-to-tail stackings through the above multiple weak interactions are observed for both of them (Figure 4C). In supramolecular chemistry, noncovalent interactions such as hydrogen bonding and IKI interactions have been widely used as the driving forces to construct higher-order structures such


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molecular conformation and distinct packing modes of these two chiral enantiomers, these differences at molecular level could be amplified gradually with the evolution of hierarchical selfassembly process, which may ultimately result in different supramolecular helical morphologies with opposite handedness and different helical pitch (Figure 2, Figures S25 and S26).59 To better explore their aggregation and self-assembly processes at the atomic level, theoretical calculation based on B3LYP/6-31G/LANL2DZ level and CPCM (conductor polarizable continuum model) solvation model was performed. The optimized structures of monomers, dimers and tetramers for (S)-1 and (R)-1 with different packing modes in THF/water (1/4, v/v) have been presented in Figure 4D and Figure S30. The calculated energies of dimers with different packing modes indicate that their respective dimer prefers to stack in a parallel and head-to-tail pattern with lower potential energy (Table S2), which is consistent with the crystal packing results. When two dimers are further integrated together to constitute tetramers (T1–T3) in the longitudinal or lateral direction with different modes, the T3 mode is dominant over the other two counterparts T1 and T2. While their energy differences are much smaller than those of the dimers (D1 and D2) implying that the strong layer-layer interaction with collective effect may minimize the energy difference in different packing modes. Combining with the crystal structural analysis, we can rationalize the packing variation for the assembly process: Firstly, the molecules both tend to pack into single layer structures at their lowest dimension, which are then followed by the wrapping up of multilayers in the longitudinal and lateral directions. Ultimately, multi-dimensional growth leads to the formation of higher-ordered helical fibers at lower energy as verified by the microscopic observations.


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(E, F) fluorescent images of rods formed by BPEA (C, E) and (S)-1/BPEA (D, F, co-assembly system). In the above self-assembly systems, we did not detect any obvious CPL signals. It is probably due to the weak luminescence of the enantiomers. It has been reported that a co-assembly of a chiral luminogen with other luminogens can efficiently enhance the CPL signal.66,67,84-88 Inspired by this idea, we employ a role-sharing and complementary strategy to construct a two-component co-assembly system; the chiral Au complexes (S)-1 and (R)-1 were used as chiral templates and typical luminogens were selected to act as chiral acceptors. The two components were expected to perform cooperatively to realize a higher output of CPL-active systems. We first chose conventional luminophors with aggregation-caused quenching (ACQ) effect and co-assembled it with chiral enantiomers (S)-1 and (R)-1 to testify this co-assembly strategy. The luminogen 9,10bis(phenylethynyl)anthracene (BPEA) was used as the achiral I

"

to co-assembly with the

chiral Au complex. A typical procedure was the same as that reported in the reference.51 First, the complex (S)-1 or (R)-1 and BPEA were dissolved into good THF solvent with molar ratio of 1:1. Then 4-fold volume of water was added to THF solution to get a homogeneous and turbid solution. The concentration of BPEA is fixed as 5 × 10-5 M to guarantee the solubility of BPEA in the mixture. After storing for three days, the above solution was routinely measured with the CD spectrometer (Figure S31). Multiple new peaks were observed at the range of 320-550 nm for both of them, which originated from the BPEA component based on the absorption analysis, indicating the successful chiral induction through co-assembly route. The above exciting results spurred us to further measure their corresponding co-assembled structures. For comparison, the SEM images of pure BPEA in the aggregate states were also captured. As shown in Figure 5 and Figure S32, BPEA formed regular rod-like structures; after


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co-assembling with complex (S)-1 or (R)-1, slender and longer rods were observed. The FLM images (Figure 5 and Figure S33) revealed the formation of bright orange microcrystals for both co-assembled systems, which completely differed from the original green luminescence solely from the BPEA assemblies and the weak emission solely from the enantiomers. The merged color of the co-assembled emission agreed well with the results of spectral measurements in solution states (Figure S34), confirming the successful co-assembly between (S)-1/(R)-1 and BPEA. We further test if the co-assembly system can efficiently lead to the CPL enhancement. Strong CPL signals centered at 560 nm for both co-assembly systems were detected with the luminescence dissymmetry factor (|glum|)89 values of ~1 × 10-3, measured using a JASCO CPL-300 spectrometer (Figure 5B and Figures S35 and S36), which are comparable values for conventional pure organic assembled systems.52,58 To further testify that this co-assembly strategy is not only restricted to conventional ACQ luminophores, we also co-assembled achiral AIEgens with (S)-1 and (R)-1. We tested our typical highly emissive AIEgens in the aggregate state, tetraphenyl ethylene (TPE)90 and 2,3,5,6tetrakis(4-methoxyphenyl)pyrazine (TPP-4M)91 by using similar co-assembly strategies used for BPEA. The pertinent induced CD spectra, absorption and FLM imaging information have been presented in Figures S37-S40. As shown in Figure 5B, Figures S35 and S36, when (S)-1 and (R)1 co-assembled with the blue luminogens TPE and TPP-4M, respectively, desirable CPL profiles centered at 470 nm (co-assembled with TPE) and 410 nm (co-assembled with TPP-4M) were observed and reasonably high glum values could be obtained (3~5 × 10-3). Therefore, we envisage the above template-directed CPL induction method might provide a facile and effective strategy to achieve the fabrication of a variety of CPL-active materials. Systematic work is still in demand


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to make an extension to realize CPL modulation via tailored co-assemblies with various AIEgens in the further work. CONCLUSIONS In summary, two AIE-active chiral Au(I) complexes have been synthesized in this work, in which their specific aggregates undergo spontaneous hierarchical self-assembly to achieve inverse helical architectures. In situ and real-time CD monitoring for the entire dynamic self-assembly processes reveals an impressive chiral inversion and significant amplification during the hierarchical evolution processes from vesicles to helical fibers. In addition, we have successfully realized the induction of CPL signals from achiral luminogens by utilizing the present chiral enantiomers as chiral transcription templates. Therefore, this study may provide inspiring insight into the hierarchical self-assembly mechanisms, which will facilitate in-depth understanding of the origin of living helical architectures and provide guidance for the fabrication of various chiral functional materials through assembly approach. Meanwhile, we also present a facile and effective strategy to realize the induction of CPL signals. And its extension to realize CPL modulation via tailored co-assemblies with various AIEgens is underway. EXPERIMENTAL SECTION Materials. The target complexes were prepared along the synthetic route presented in Scheme S1. The detail experimental procedure and synthetic methods are described in Supporting Information. Other reagents were purchased and used as received. 1H, 13C and 19F NMR spectra were measured on a Bruker AVIII 400 MHz NMR spectrometer. High-resolution mass spectra (HRMS) were recorded on a GCT Premier CAB 048 mass spectrometer system operating in a MALDI-TOF mode. UV spectra were measured on a Varian CARY 50 UV-visible


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spectrophotometer. PL spectra were recorded on a PerkinElmer LS 55 spectrofluorometer. X-ray diffraction measurements were conducted on a Nonius Kappa CCD diffractometer with Mo $\ radiation and a D/max-2550 PC X-ray diffractometer with Cu $\ radiation. Circular dichroism (CD) spectra were recorded with a Chirascan spectrometer (Applied Photophysics, England). Circularly polarized photoluminescence (CPPL) spectra were recorded on a commercialized instrument JASCO CPL-300. Morphological characterizations. The Morphological structures of the aggregates were investigated by a Bruker Multimode VIII atom force microscopy (AFM) instrument, FEI Tecnai G2 F30 transmission electron microscopy (TEM) and HITACHI-SU8010 scanning electron microscope (SEM) at accelerating voltages of 200 and 5 kV, respectively. Fluorescence images were captured using the fluorescence microscope DHG-9070A (Olympus, Japan). Sample preparation. Stock solutions of (S)-1 and (R)-1 in THF (1 mmol) were prepared. A certain volume (20 ] > of such stock solutions were transferred to small glass vials (5 mL). After adding appropriate amounts of THF, distilled water was added dropwise under vigorous stirring to afford 0.1 mmol or 50 ]

(S)-1 and (R)-1 aggregate solutions. The mixtures were dropped on

silicon wafers and the solvents were removed under reduced pressure at room temperature, and the SEM images of the aggregates on silicon wafers were taken. Theoretical calculation. DFT calculations were performed with the Gaussian 09 program, at the B3LYP/6-31G level of theory. The basis set employed was 6-31G (Lanl2DZ for Au atoms). Geometry optimization was performed without any symmetry constraints. To account for solvent effects, the conductor polarizable continuum model (CPCM) in THF/water (1:4, v/v) was employed.92


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ASSOCIATED CONTENT Supporting Information. Materials and methods, synthetic procedures, characterization, property investigation and crystallographic data are available free of charge via the Internet at http://pubs.acs.org. AUTHOR INFORMATION Corresponding Authors *[email protected] (B. S. Li) *[email protected] (B. Z. Tang) Author Contributions # These

authors contributed equally.

ACKNOWLEDGMENT We are grateful for financial support from the National Natural Science Foundation of China (21788102, 21472059 and 21574085), the Research Grants Council of Hong Kong (16308016, C2014-15G, C6009-17G, and A-HKUST605/16), the Innovation and Technology Commission (ITC-CNERC14SC01), the Science and Technology Plan of Shenzhen (JCYJ20160229205601482 and JCYJ20140425170011516), the China Postdoctoral Science Foundation (2016M602532 and 2017T100646), and the National Natural Science Foundation of Guangdong province (2016A030312002 and 2017A030313067). REFERENCES


22

Page 23 of 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

1.

Boncheva, M.; Whitesides, G. M. Biomimetic Approaches to the Design of Functional,

Self-Assembling Systems. Dekker Encyclopedia of Nanoscience and Nanotechnology; 2004; pp 287-294. 2.

Lee, Y. S. Self-Assembly and Nanotechnology: a Force Balance Approach. John Wiley &

Sons: 2008. 3.

Xu, J.; Liu, X.; Lv, J.; Zhu, M.; Huang, C.; Zhou, W.; Yin, X.; Liu, H.; Li, Y.; Ye, J.

Morphology Transition and Aggregation-Induced Emission of an Intramolecular Charge-Transfer Compound. Langmuir 2008, 24, 4231-4237. 4.

Mai, Y.; Eisenberg, A. Self-Assembly of Block Copolymers. Chem. Soc. Rev. 2012, 41,

5969-5985. 5.

Rest, C.; Kandanelli, R.; Fernández, G. Strategies to Create Hierarchical Self-assembled

Structures via Cooperative Non-Covalent Interactions. Chem. Soc. Rev. 2015, 44, 2543-2572. 6.

Keizer, H. M.; Sijbesma, R. P. Hierarchical Self-Assembly of Columnar Aggregates.

Chem. Soc. Rev. 2005, 34, 226-234. 7.

Datta, S.; Saha, M. L.; Stang, P. J. Hierarchical Assemblies of Supramolecular

Coordination Complexes. Acc. Chem. Res. 2018, 51, 2047-2063. 8.

Kastelic, J.; Palley, I.; Baer, E. A Structural Mechanical Model for Tendon Crimping. J.

Biomech. 1980, 13, 887-893. 9.

Lopes, W. A.; Jaeger, H. M. Hierarchical Self-assembly of Metal Nanostructures on

Diblock Copolymer Scaffolds. Nature 2001, 414, 735-738. 10.

Liu, B.; Zeng, H. C. Room Temperature Solution Synthesis of Monodispersed Single-

Crystalline ZnO Nanorods and Derived Hierarchical Nanostructures. Langmuir 2004, 20, 41964204.


23

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

11.

Page 24 of 34

Wu, H.; Thalladi, V. R.; Whitesides, S.; Whitesides, G. M. Using Hierarchical Self-

Assembly To Form Three-Dimensional Lattices of Spheres. J. Am. Chem. Soc. 2002, 124, 1449514502. 12.

Whang, D.; Jin, S.; Wu, Y.; Lieber, C. M. Large-Scale Hierarchical Organization of

Nanowire Arrays for Integrated Nanosystems. Nano Lett. 2003, 3, 1255-1259. 13.

Wang, M.; Du, L.; Wu, X.; Xiong, S.; Chu, P. K. Charged Diphenylalanine Nanotubes and

Controlled Hierarchical Self-Assembly. ACS Nano 2011, 5, 4448-4454. 14.

Kim, B. H.; Shin, D. O.; Jeong, S.-J.; Koo, C. M.; Jeon, S. C.; Hwang, W. J.; Lee, S.; Lee,

M. G.; Kim, S. O. Hierarchical Self-Assembly of Block Copolymers for Lithography-Free Nanopatterning. Adv. Mater. 2008, 20, 2303-2307. 15.

Hifsudheen, M.; Mishra, R. K.; Vedhanarayanan, B.; Praveen, V. K.; Ajayaghosh, A. The

Helix to Super-Helix Transition in the Self-Assembly of I

: Superseding of Molecular

Chirality at Hierarchical Level. Angew. Chem., Int. Ed. 2017, 56, 12634-12638. 16.

Miszta, K.; de Graaf, J.; Bertoni, G.; Dorfs, D.; Brescia, R.; Marras, S.; Ceseracciu, L.;

Cingolani, R.; van Roij, R.; Dijkstra, M.; Manna, L. Hierarchical Self-Assembly of Suspended Branched Colloidal Nanocrystals into Superlattice Structures. Nat. Mater. 2011, 10, 872-876. 17.

Tian, Y.; Yan, X.; Saha, M. L.; Niu, Z.; Stang, P. J. Hierarchical Self-Assembly of

Responsive Organoplatinum(II) Metallacycle–TMV Complexes with Turn-On Fluorescence. J. Am. Chem. Soc. 2016, 138, 12033-12036. 18.

Lv, Z.; Chen, Z.; Shao, K.; Qing, G.; Sun, T. Stimuli-Directed Helical Chirality Inversion

and Bio-Applications. Polymers 2016, 8, 310-328. 19.

Pokroy, B.; Kang, S. H.; Mahadevan, L.; Aizenberg, J. Self-Organization of a Mesoscale

Bristle into Ordered, Hierarchical Helical Assemblies. Science 2009, 323, 237-240.


24

Page 25 of 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

20.

Zotti, M. D.; Formaggio, F.; Crisma, M.; Peggion, C.; Moretto, A.; Toniolo, C. Handedness

Preference and Switching of Peptide Helices. Part I: Helices Based on Protein Amino Acids. J. Pept. Sci. 2014, 20, 307-322. 21.

Rich, A.; Zhang, S. Z-DNA: the Long Road to Biological Function. Nat. Rev. Genet. 2003,

4, 566-572. 22.

Song, G.; Ren, J. Recognition and Regulation of Unique Nucleic Acid Structures by Small

Molecules. Chem. Commun. 2010, 46, 7283-7294. 23.

Lockhart, D. J.; Winzeler, E. A. Genomics, Gene Expression and DNA Arrays. Nature

2000, 405, 827-836. 24.

Xing, P.; Chen, H.; Bai, L.; Hao, A.; Zhao, Y. Superstructure Formation and Topological

Evolution Achieved by Self-Organization of a Highly Adaptive Dynamer. ACS Nano 2016, 10, 2716-2727. 25.

Zhu, Y.; Wang, H.; Wan, K.; Guo, J.; He, C.; Yu, Y.; Zhao, L.; Zhang, Y.; Lv, J.; Shi, L.;

Jin, R.; Zhang, X.; Shi, X.; Tang, Z. Enantioseparation of Au20(PP3)4Cl4 Clusters with Intrinsically Chiral Cores. Angew. Chem., Int. Ed. 2018, 57, 9059-9063. 26.

Gong, J.; Newman, R. S.; Engel, M.; Zhao, M.; Bian, F.; Glotzer, S. C.; Tang, Z. Shape-

Dependent Ordering of Gold Nanocrystals into Large-Scale Superlattices. Nat. Commun. 2017, 8, 14038-14046. 27.

Lv, J.; Hou, K.; Ding, D.; Wang, D.; Han, B.; Gao, X.; Zhao, M.; Shi, L.; Guo, J.; Zheng,

Y.; Zhang, X.; Lu, C.; Huang, L.; Huang, W.; Tang, Z. Gold Nanowire Chiral Ultrathin Films with Ultrastrong and Broadband Optical Activity. Angew. Chem., Int. Ed. 2017, 56, 5055-5060.


25

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

28.

Page 26 of 34

Zhou, Y.; Marson, R. L.; van Anders, G.; Zhu, J.; Ma, G.; Ercius, P.; Sun, K.; Yeom, B.;

Glotzer, S. C.; Kotov, N. A. Biomimetic Hierarchical Assembly of Helical Supraparticles from Chiral Nanoparticles. ACS Nano 2016, 10, 3248-3256. 29.

Yeom, J.; Yeom, B.; Chan, H.; Smith, K. W.; Dominguez-Medina, S.; Bahng, Joong H.;

Zhao, G.; Chang, W.-S.; Chang, S.-J.; Chuvilin, A.; Melnikau, D.; Rogach, A. L.; Zhang, P.; Link, S.; Král, P.; Kotov, N. A. Chiral Templating of Self-Assembling Nanostructures by Circularly Polarized Light. Nat. Mater. 2014, 14, 66-72. 30.

Yashima, E.; Maeda, K.; Okamoto, Y. Memory of Macromolecular Helicity Assisted by

Interaction with Achiral Small Molecules. Nature 1999, 399, 449-451. 31.

Shimomura, K.; Ikai, T.; Kanoh, S.; Yashima, E.; Maeda, K. Switchable Enantioseparation

Based on Macromolecular Memory of a Helical Polyacetylene in the Solid State. Nat. Chem. 2014, 6, 429-434. 32. F.

Yan, X.; Li, S.; Cook, T. R.; Ji, X.; Yao, Y.; Pollock, J. B.; Shi, Y.; Yu, G.; Li, J.; Huang, Hierarchical

Self-Assembly:

Well-Defined

Supramolecular

Nanostructures

and

Metallohydrogels via Amphiphilic Discrete Organoplatinum (II) Metallacycles. J. Am. Chem. Soc. 2013, 135, 14036-14039. 33.

Jonkheijm, P.; van der Schoot, P.; Schenning, A. P. H. J.; Meijer, E. W. Probing the

Solvent-Assisted Nucleation Pathway in Chemical Self-Assembly. Science 2006, 313, 80-83. 34.

Wei, P.; Zhang, J.-X.; Zhao, Z.; Chen, Y.; He, X.; Chen, M.; Gong, J.; Sung, H. H. Y.;

Williams, I. D.; Lam, J. W. Y.; Tang, B. Z. Multiple yet Controllable Photoswitching in a Single AIEgen System. J. Am. Chem. Soc. 2018, 140, 1966-1975. 35.

Liu, M.; Zhang, L.; Wang, T. Supramolecular Chirality in Self-Assembled Systems. Chem.

Rev. 2015, 115, 7304-7397.


26

Page 27 of 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

36.

Gottarelli, G.; Lena, S.; Masiero, S.; Pieraccini, S.; Spada, G. P. The Use of Circular

Dichroism Spectroscopy for Studying the Chiral Molecular Self-Assembly: An Overview. Chirality 2008, 20, 471-485. 37.

Maeda, K.; Yashima, E. Dynamic Helical Structures: Detection and Amplification of

Chirality. In Supramolecular Chirality, Crego-Calama, M.; Reinhoudt, D. N., Eds. Springer Berlin Heidelberg: Berlin, Heidelberg, 2006; pp 47-88. 38.

Yashima, E.; Ousaka, N.; Taura, D.; Shimomura, K.; Ikai, T.; Maeda, K. Supramolecular

Helical Systems: Helical Assemblies of Small Molecules, Foldamers, and Polymers with Chiral Amplification and Their Functions. Chem. Rev. 2016, 116, 13752-13990. 39.

Pescitelli, G.; Di Bari, L.; Berova, N. Application of Electronic Circular Dichroism in the

Study of Supramolecular Systems. Chem. Soc. Rev. 2014, 43, 5211-5233. 40.

Hau, F. K.-W.; Lee, T. K.-M.; Cheng, E. C.-C.; Au, V. K.-M.; Yam, V. W.-W.

Luminescence Color Switching of Supramolecular Assemblies of Discrete Molecular Decanuclear Gold(I) Sulfido Complexes. Proc. Natl. Acad. Sci. U. S. A. 2014, 111, 15900-15905. 41.

Tan, S. F.; Chee, S. W.; Lin, G.; Mirsaidov, U. Direct Observation of Interactions between

Nanoparticles and Nanoparticle Self-Assembly in Solution. Acc. Chem. Res. 2017, 50, 1303-1312. 42.

Yao, L.-Y.; Hau, F. K.-W.; Yam, V. W.-W. Addition Reaction-Induced Cluster-to-Cluster

Transformation: Controlled Self-Assembly of Luminescent Polynuclear Gold(I) ]3-Sulfido Clusters. J. Am. Chem. Soc. 2014, 136, 10801-10806. 43.

Ruiz, J.; García, L.; Sol, D.; Vivanco, M. Template Synthesis, Metalation, and Self-

Assembly of Protic Gold(I)/(NHC)2 Tectons Driven by Metallophilic Interactions. Angew. Chem., Int. Ed. 2016, 55, 8386-8390.


27

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

44.

Page 28 of 34

Mohr, F.; Jennings, M. C.; Puddephatt, R. J. Self-Assembly in Gold(I) Chemistry: A

Double-Stranded Polymer with Interstrand Aurophilic Interactions. Angew. Chem., Int. Ed. 2004, 43, 969-971. 45.

Nakagawa, M.; Kawai, T. Chirality-Controlled Syntheses of Double-Helical Au

Nanowires. J. Am. Chem. Soc. 2018, 140, 4991-4994. 46.

Shi, L.; Zhu, L.; Guo, J.; Zhang, L.; Shi, Y.; Zhang, Y.; Hou, K.; Zheng, Y.; Zhu, Y.; Lv,

J.; Liu, S.; Tang, Z. Self-Assembly of Chiral Gold Clusters into Crystalline Nanocubes of Exceptional Optical Activity. Angew. Chem., Int. Ed. 2017, 56, 15397-15401. 47.

Yao, L.-Y.; Lee, T. K.-M.; Yam, V. W.-W. Thermodynamic-Driven Self-Assembly:

Heterochiral Self-Sorting and Structural Reconfiguration in Gold(I)–Sulfido Cluster System. J. Am. Chem. Soc. 2016, 138, 7260-7263. 48.

Aguiló, E.; Moro, A. J.; Gavara, R.; Alfonso, I.; Pérez, Y.; Zaccaria, F.; Guerra, C. F.;

Malfois, M.; Baucells, C.; Ferrer, M.; Lima, J. C.; Rodríguez, L. Reversible Self-Assembly of Water-Soluble Gold(I) Complexes. Inorg. Chem. 2018, 57, 1017-1028. 49.

Tiekink, E. R. T. Supramolecular Assembly of Molecular Gold(I) Compounds: An

Evaluation of the Competition and Complementarity between Aurophilic (Au Au) and Conventional Hydrogen Bonding Interactions. Coord. Chem. Rev. 2014, 275, 130-153. 50.

Lima, J.; Rodríguez, L. Supramolecular Gold Metallogelators: The Key Role of

Metallophilic Interactions. Inorganics 2015, 3, 1-18. 51.

Yang, D.; Duan, P.; Zhang, L.; Liu, M. Chirality and Energy Transfer Amplified Circularly

Polarized Luminescence in Composite Nanohelix. Nat. Commun. 2017, 8, 15727-15735. 52.

Kumar, J.; Nakashima, T.; Kawai, T. Circularly Polarized Luminescence in Chiral

Molecules and Supramolecular Assemblies. J. Phys. Chem. Lett. 2015, 6, 3445-3452.


28

Page 29 of 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

53.

Carr, R.; Evans, N. H.; Parker, D. Lanthanide Complexes as Chiral Probes Exploiting

Circularly Polarized Luminescence. Chem. Soc. Rev. 2012, 41, 7673-7686. 54.

Brandt, J. R.; Salerno, F.; Fuchter, M. J. The Added Value of Small-Molecule Chirality in

Technological Applications. Nat. Rev. Chem. 2017, 1, 0045-0056. 55.

Kim, J.; Lee, J.; Kim, W. Y.; Kim, H.; Lee, S.; Lee, H. C.; Lee, Y. S.; Seo, M.; Kim, S. Y.

Induction and Control of Supramolecular Chirality by Light in Self-Assembled Helical Nanostructures. Nat. Commun. 2015, 6, 6959-6966. 56.

Liu, Q.; Xia, Q.; Wang, S.; Li, B. S.; Tang, B. Z. In Situ Visualizable Self-Assembly,

Aggregation-Induced Emission and Circularly Polarized Luminescence of Tetraphenylethene and Alanine-Based Chiral Polytriazole. J. Mater. Chem. C 2018, 6, 4807-4816. 57.

Hong, Y.; Lam, J. W. Y.; Tang, B. Z. Aggregation-Induced Emission. Chem. Soc. Rev.

2011, 40, 5361-5388. 58.

Roose, J.; Tang, B. Z.; Wong, K. S. Circularly-Polarized Luminescence (CPL) from Chiral

AIE Molecules and Macrostructures. Small 2016, 12, 6495-6512. 59.

Li, B. S.; Wen, R.; Xue, S.; Shi, L.; Tang, Z.; Wang, Z.; Tang, B. Z. Fabrication of Circular

Polarized Luminescent Helical Fibers from Chiral Phenanthro[9,10]imidazole Derivatives. Mater. Chem. Front. 2017, 1, 646-653. 60.

Yang, Y.; da Costa, R. C.; Smilgies, D.-M.; Campbell, A. J.; Fuchter, M. J. Induction of

Circularly Polarized Electroluminescence from an Achiral Light-Emitting Polymer via a Chiral Small-Molecule Dopant. Adv. Mater. 2013, 25, 2624-2628. 61.

Wynberg, H.; Meijer, E. W.; Hummelen, J. C.; Dekkers, H. P. J. M.; Schippers, P. H.;

Carlson, A. D. Circular Polarization Observed in Bioluminescence. Nature 1980, 286, 641-642.


29

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

62.

Page 30 of 34

Maeda, H.; Bando, Y.; Shimomura, K.; Yamada, I.; Naito, M.; Nobusawa, K.; Tsumatori,

H.; Kawai, T. Chemical-Stimuli-Controllable Circularly Polarized Luminescence from AnionResponsive I 63.

J

Molecules. J. Am. Chem. Soc. 2011, 133, 9266-9269.

Goto, T.; Okazaki, Y.; Ueki, M.; Kuwahara, Y.; Takafuji, M.; Oda, R.; Ihara, H. Induction

of Strong and Tunable Circularly Polarized Luminescence of Nonchiral, Nonmetal, LowMolecular-Weight Fluorophores Using Chiral Nanotemplates. Angew. Chem., Int. Ed. 2017, 56, 2989-2993. 64.

Aoki, R.; Toyoda, R.; Kögel, J. F.; Sakamoto, R.; Kumar, J.; Kitagawa, Y.; Harano, K.;

Kawai, T.; Nishihara, H. Bis(dipyrrinato)zinc(II) Complex Chiroptical Wires: Exfoliation into Single Strands and Intensification of Circularly Polarized Luminescence. J. Am. Chem. Soc. 2017, 139, 16024-16027. 65.

Song, F.; Xu, Z.; Zhang, Q.; Zhao, Z.; Zhang, H.; Zhao, W.; Qiu, Z.; Qi, C.; Zhang, H.;

Sung, H. H. Y.; Williams, I. D.; Lam, J. W. Y.; Zhao, Z.; Qin, A.; Ma, D.; Tang, B. Z. Highly Efficient Circularly Polarized Electroluminescence from Aggregation-Induced Emission Luminogens with Amplified Chirality and Delayed Fluorescence. Adv. Funct. Mater. 2018, 28, 1800051-1800062. 66.

Watanabe, K.; Iida, H.; Akagi, K. Circularly Polarized Blue Luminescent Spherulites

Consisting of Hierarchically Assembled Ionic Conjugated Polymers with a Helically I

@

Structure. Adv. Mater. 2012, 24, 6451-6456. 67.

Han, J.; You, J.; Li, X.; Duan, P.; Liu, M. Full-Color Tunable Circularly Polarized

Luminescent Nanoassemblies of Achiral AIEgens in Confined Chiral Nanotubes. Adv. Mater. 2017, 29, 1606503-1606510.


30

Page 31 of 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

68.

Mei, J.; Hong, Y.; Lam, J. W. Y.; Qin, A.; Tang, Y.; Tang, B. Z. Aggregation-Induced

Emission: The Whole Is More Brilliant than the Parts. Adv. Mater. 2014, 26, 5429-5479. 69.

Hong, Y. N.; Lam, J. W. Y.; Tang, B. Z. Aggregation-Induced Emission: Phenomenon,

Mechanism and Applications. Chem. Commun. 2009, 4332-4353. 70.

Murata, K.; Aoki, M.; Suzuki, T.; Harada, T.; Kawabata, H.; Komori, T.; Ohseto, F.; Ueda,

K.; Shinkai, S. Thermal and Light Control of the Sol-Gel Phase Transition in Cholesterol-Based Organic Gels. Novel Helical Aggregation Modes As Detected by Circular Dichroism and Electron Microscopic Observation. J. Am. Chem. Soc. 1994, 116, 6664-6676. 71.

Nakade, H.; Jordan, B. J.; Xu, H.; Han, G.; Srivastava, S.; Arvizo, R. R.; Cooke, G.;

Rotello, V. M. Chiral Translation and Cooperative Self-Assembly of Discrete Helical Structures Using Molecular Recognition Dyads. J. Am. Chem. Soc. 2006, 128, 14924-14929. 72.

Di Bari, L.; Pescitelli, G.; Salvadori, P. Conformational Study of 2,2’-Homosubstituted

1,1’-Binaphthyls by Means of UV and CD Spectroscopy. J. Am. Chem. Soc. 1999, 121, 79988004. 73.

Mori, T.; Sharma, A.; Hegmann, T. Significant Enhancement of the Chiral Correlation

Length in Nematic Liquid Crystals by Gold Nanoparticle Surfaces Featuring Axially Chiral Binaphthyl Ligands. ACS Nano 2016, 10, 1552-1564. 74.

Sheng, Y.; Shen, D.; Zhang, W.; Zhang, H.; Zhu, C.; Cheng, Y. Reversal Circularly

Polarized Luminescence of AIE-Active Chiral Binaphthyl Molecules from Solution to Aggregation. Chem. - Eur. J. 2015, 21, 13196-13200. 75.

Huang, C.; Wen, L.; Liu, H.; Li, Y.; Liu, X.; Yuan, M.; Zhai, J.; Jiang, L.; Zhu, D.

Controllable Growth of 0D to Multidimensional Nanostructures of a Novel Porphyrin Molecule. Adv. Mater. 2009, 21, 1721-1725.


31

ACS Nano 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

76.

Page 32 of 34

Sanji, T.; Kato, N.; Kato, M.; Tanaka, M. Helical Folding in a Helical Channel: Chiroptical

Transcription of Helical Information Through Chiral Wrapping. Angew. Chem., Int. Ed. 2005, 44, 7301-7304. 77.

Lohr, A.; Lysetska, M.; Würthner, F. Supramolecular Stereomutation in Kinetic and

Thermodynamic Self Assembly of Helical Merocyanine Dye Nanorods. Angew. Chem., Int. Ed. 2005, 44, 5071-5074. 78.

Li, B.S.; Li, H.; Tang, B.Z. Molecular Design, Circularly Polarized and Helical

Self Assembly of Chiral Aggregation Induced Emission Molecules. Chem. - Asian J. Doi: 10.1002/asia.201801469. 79.

Cai, Y.; Guo, Z.; Chen, J.; Li, W.; Zhong, L.; Gao, Y.; Jiang, L.; Chi, L.; Tian, H.; Zhu,

W.-H. Enabling Light Work in Helical Self-Assembly for Dynamic Amplification of Chirality with Photoreversibility. J. Am. Chem. Soc. 2016, 138, 2219-2224. 80.

Leung, F. C.-M.; Leung, S. Y.-L.; Chung, C. Y.-S.; Yam, V. W.-W. Metal–Metal and I–I

Interactions Directed End-to-End Assembly of Gold Nanorods. J. Am. Chem. Soc. 2016, 138, 2989-2992. 81.

Engel, S.; Fritz, E.-C.; Ravoo, B. J. New Trends in the Functionalization of Metallic Gold:

from Organosulfur Ligands to N-Heterocyclic Carbenes. Chem. Soc. Rev. 2017, 46, 2057-2075. 82.

Ghimire, M. M.; Nesterov, V. N.; Omary, M. A. Remarkable Aurophilicity and

Photoluminescence Thermochromism in a Homoleptic Cyclic Trinuclear Gold(I) Imidazolate Complex. Inorg. Chem. 2017, 56, 12086-12089. 83.

Pinto, A.; Svahn, N.; Lima, J. C.; Rodríguez, L. Aggregation Induced Emission of Gold(I)

Complexes in Water or Water Mixtures. Dalton Trans. 2017, 46, 11125-11139.


32

Page 33 of 34 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Nano

84.

Yu, Z.; Erbas, A.; Tantakitti, F.; Palmer, L. C.; Jackman, J. A.; Olvera de la Cruz, M.; Cho,

N.-J.; Stupp, S. I. Co-assembly of Peptide Amphiphiles and Lipids into Supramolecular Nanostructures Driven by 85.

KI Interactions. J. Am. Chem. Soc. 2017, 139, 7823-7830.

Babu, S. S.; Praveen, V. K.; Ajayaghosh, A. Functional I 8

and Their Applications.

Chem. Rev. 2014, 114, 1973-2129. 86.

Duan, P.; Cao, H.; Zhang, L.; Liu, M. Gelation Induced Supramolecular Chirality: Chirality

Transfer, Amplification and Application. Soft Matter 2014, 10, 5428-5448. 87.

Liu, G.-F.; Zhu, L.-Y.; Ji, W.; Feng, C.-L.; Wei, Z.-X. Inversion of the Supramolecular

Chirality of Nanofibrous Structures through Co-Assembly with Achiral Molecules. Angew. Chem., Int. Ed. 2016, 55, 2411-2415. 88.

Ogoshi, T.; Sueto, R.; Yoshikoshi, K.; Yasuhara, K.; Yamagishi, T. Spherical Vesicles

Formed by Co-Assembly of Cyclic Pentagonal Pillar[5]quinone with Cyclic Hexagonal Pillar[6]arene. J. Am. Chem. Soc. 2016, 138, 8064-8067. 89.

Berova, N.; Nakanishi, K.; Woody, R. W.; Woody, R. Circular Dichroism: Principles and

Applications. John Wiley & Sons: 2000. 90.

Dong, Y.; Lam, J. W.; Qin, A.; Liu, J.; Li, Z.; Tang, B. Z.; Sun, J.; Kwok, H. S.

Aggregation-Induced Emissions of Tetraphenylethene Derivatives and Their Utilities as Chemical Vapor Sensors and in Organic Light-Emitting Diodes. Appl. Phys. Lett. 2007, 91, 011111-011113. 91.

Chen, M.; Li, L.; Nie, H.; Tong, J.; Yan, L.; Xu, B.; Sun, J. Z.; Tian, W.; Zhao, Z.; Qin,

A.; Tang, B. Z. Tetraphenylpyrazine-Based AIEgens: Facile Preparation and Tunable Light Emission. Chem. Sci. 2015, 6, 1932-1937.


33

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Assembly and Induction of Circularly Polarized Luminescence from

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