Artificial Light-harvesting Systems Research Articles

Two-step, sequential, efficient, artificial light-harvesting systems based on twisted cucurbit[14]uril for manufacturing white light emission materials

White-light-emitting (WLE) materials have promising and valuable applications in controllable lighting, screen displays and sensing. In this study, a two-step sequence of highly efficient artificial light-harvesting systems (ALHSs) with white light emission is successfully constructed in the aqueous phase through a non-covalent bond among imidazole derivatives (DIm), twisted cucurbit[14]uril (tQ[14]), eosin Y (ESY), and Nile red (NiR). The prepared linear supramolecular polymer (DIm@tQ[14]) constructed by DIm and tQ[14] through host–guest interaction is an ideal energy donor due to its superior aggregation-induced emission effect, which enables one-step energy transfer by loading ESY and two-step energy transfer by further loading NiR with a high efficiency of 91.47%. The emission color of the two-step sequential ALHSs changes from cyan to chartreuse then to orange-red, and bright white light emission can be achieved by controlling the donor/acceptor molar ratio. Moreover, the assemblies of the two-step sequential ALHSs can be applied to white LED materials. This research not only simulates the multi-step energy transfer process in nature but also has an attractive commercial value in the manufacturing of WLE materials.

Host‐Guest Assemblies of Cyanostilbenes and Cucurbit[8]uril: Luminescence Modulation, Photoreactivity Control and Energy Transfer Studies

AbstractA series of di‐cationic cyanostilbene derivatives possessing peripheral alkyl chains of variable lengths underwent host‐guest complexation withCB[8]in aqueous media to produce higher order nano‐ and micro‐structures of various morphologies and exhibited multi‐color luminescence. Their complexation behavior was modulated by varying the ionic strength of the medium. The photoreactivity of the cyanostilbene chromophores in theCB[8]assemblies was found to be dependent on the length of the alkyl segment. Furthermore, theCB[8]assemblies acted as artificial light harvesting systems exhibiting multicolor luminescence ranging from green to pinkish red through energy transfer to different acceptor dyes.

An efficient supramolecular artificial light-harvesting system based on twisted cucurbit[15]uril and cucurbit[10]uril for live cell imaging

The construction of highly efficient artificial light-harvesting systems in aqueous solutions is still challenging. Herein, we reported a new light-harvesting system based on the supramolecular combination of twisted cucurbit[15]uril (tQ[15]), cucurbit[10]uril (Q[10]), and an anthracene derivative (APy) with aggregation-induced emission (AIE) properties. The Q[n]-based linear supramolecular polymer, APy@tQ[15]@Q[10], was constructed through a two-step assembly strategy. Subsequently, a highly efficient artificial light-harvesting system with relatively high antenna effect and energy transfer efficiency was successfully constructed through non-covalent interactions between Rhodamine B (RB, acceptor) and the APy@tQ[15]@Q[10] (donor). The resulting system was compatible with HeLa cells and could be used for live-cell imaging in the red channel. This supramolecular assembly strategy has not only produced a highly efficient light-harvesting system but also expands the application of Q[n]s in the biomedical field.

Synchronous Imaging in Golgi Apparatus and Lysosome Enabled by Amphiphilic Calixarene-Based Artificial Light-Harvesting Systems.

Artificial supramolecular light-harvesting systems have expanded various properties on photoluminescence, enabling promising applications on cell imaging, especially for imaging in organelles. Supramolecular light-harvesting systems have been used for imaging in some organelles such as lysosome, Golgi apparatus, and mitochondrion, but developing a supramolecular light-harvesting platform for imaging two organelles synchronously still remains a great challenge. Here, we report a series of lower-rim dodecyl-modified sulfonato-calix[4]arene-mediated supramolecular light-harvesting platforms for efficient light-harvesting from three naphthalene diphenylvinylpyridiniums containing acceptors, Nile Red, and Nile Blue. All of the constructed supramolecular light-harvesting systems possess high light-harvesting efficiency. Furthermore, when the two acceptors are loaded simultaneously in a single light-harvesting donor system for imaging in human prostate cancer cells, organelle imaging in lysosome and Golgi apparatus can be realized at the same time with distinctive wavelength emission. Nile Red receives the light-harvesting energy from the donors, reaching orange emissions (625 nm) in lysosome while Nile Blue shows a near-infrared light-harvesting emission at 675 nm in Golgi apparatus in the same cells. Thus, the light harvesting system provides a pathway for synchronously efficient cell imaging in two distinct organelles with a single type of photoluminescent supramolecular nanoparticles.

"On/Off" Switchable Sequential Light-Harvesting Systems Based on Controllable Protein Nanosheets for Regulation of Photocatalysis.

A controllable protein nanostructures-based "On/Off" switchable artificial light-harvesting system (LHS) with sequential multistep energy transfer and photocatalysis was reported herein for mimicking the natural LHS in both structure and function. Single-layered protein nanosheets were first constructed via a reversible covalent self-assembly strategy using cricoid stable protein one (SP1) as building blocks to realize an ordered arrangement of pigments. Fluorescent chromophores like carbon dots (CDs) can be precisely distributed on the protein nanosheets superficially via electrostatic interactions and make the ratio between donors and acceptors adjustable. After being anchored with a photocatalysis center (eosin-5-isothiocyanate, EY), the constructed LHS could sequentially transfer energy between two kinds of chromophores (CD1 and CD2), and further transfer to EY center with a high efficiency of 84%. Interestingly, the Förster resonance energy transfer (FRET) process of our LHS could be reversibly "On/Off" switched by the redox regulated assembly and disassembly of SP1 building blocks. Moreover, the LHS has been further proved to promote the yield of a model cross-coupling hydrogen evolution reaction and regulate the process of the reaction with the FRET process "On/Off" state.

Toward cheaper light harvesting systems: Using earth-abundant metal oxide nanoparticles in self-assembled peptide-porphyrin nanofibers.

Cheap artificial light harvesting systems, which competently harvest solar energy and promote efficient energy transfer, are highly sought after in the renewable sector. We report the synthesis of self-assembled peptide-porphyrin fibers (SJ 6) fabricated with iron(III) oxide (Fe3 O4 ) nanoparticles as feasible electron acceptors. Charge-complementarity between the negatively charged peptide (20E) and the protonated Zn-tetraphenyl porphyrin (ZnTPyP) led to an ordered assembly of the ZnTPyP molecules, enabling efficient light harvesting. X-ray diffraction data indicates a more ordered structure in SJ 6 compared to 20E and ZnTPyP. The incorporation of Fe3 O4 nanoparticles into SJ 6 showed significant fluorescence quenching, indicating efficient electron flow from the donor to the acceptor. The SJ 6-nFe3 O4 system performed the light reaction of photosynthesis as confirmed by the reduction of 1 mM NAD+ to 0.180 mM NADH upon exposure to visible light (Xe lamp λ > 420 nm) for 1 h. The photochemical regeneration of NADH using the SJ 6-nFe3 O4 system was coupled to glutamate dehydrogenase-catalyzed conversion of α-ketoglutarate to L-glutamate. These results confirm the successful synthesis of an artificial light harvesting peptide-porphyrin system with Fe3 O4 nanoparticles as promising low-cost electron separators.

A multiple-function fluorescent pillar[5]arene: Fe3+/Ag+ detection and light-harvesting system

A novel pillar[5]arene (P5DPB) that includes a classical π -conjugated molecule, 4,4′-(1,4-phenylenedi-2,1-ethenediyl) bis-pyridine (DPB), was designed and synthesized as a substituent. Because of this modification, P5DPB exhibits several unique properties that differ from those of common pillar[5]arenes. The P5DPB neutral pyridine shows good selectivity for Ag + and Fe 3+ . The presence of Ag + ions cause a blue shift (from yellow-green to green) and a decrease in the intensity of the P5DPB emission, while the addition of Fe 3+ significantly quenches the P5DPB fluorescence. In addition, P5DPB satisfies the conditions for the construction of an energy transfer system with the commonly used Rhodamine B dye and shows great potential for the development of artificial light-harvesting systems. This work provides a new approach for the construction of energy transfer systems and a new reference for metal detection based on derivatized pillar[ n ]arenes, greatly enriching the applications of these systems. A novel pillar[5]arenes not only shows good selectivity for coordination to Ag + and Fe 3+ but also satisfies the conditions for the construction of an energy transfer system with the commonly used Rhodamine B dye.

Dynamic rotaxane-branched dendrimers with precisely arranged luminogens for efficient light harvesting

Although the development of artificial light-harvesting systems (LHSs) has attracted increasing attention, the construction of novel artificial LHSs with co-existed various types of precisely arranged luminogens has been still a major challenge. Herein, starting from [2]rotaxane building blocks AN-R or TPE-R functionalized with either anthracene or tetraphenylethene (TPE) moiety, a family of novel rotaxane-branched dendrimers containing two types of energy donors on the branches and one pyrene moiety at the central core as energy acceptor have been successfully constructed through a facile, efficient, and controllable divergent approach. Notably, attributed to the solvent-induced switching feature of the rotaxane branches, the integrated rotaxane-branched dendrimers displayed an interesting dynamic feature. More importantly, as revealed by fluorescence spectra, the resultant rotaxane-branched dendrimers displayed enhanced antenna effects along with the increase of dendrimer generation. Therefore, these rotaxane-branched dendrimers described herein could serve as not only promising platforms for light harvesting but also excellent candidates for the construction of smart supramolecular materials for practical applications.

Frontispiece: An Artificial Light‐Harvesting System with Controllable Efficiency Enabled by an Annulene‐Based Anisotropic Fluid

Light Harvesting In their Research Article (e202200466), Xu-Man Chen, Hong Yang, Quan Li et al. report an artificial light-harvesting system with controllable efficiency enabled by an annulene-based anisotropic fluid.

Naphthalenyl-phenylacrylonitrile-based supramolecular aqueous artificial light-harvesting system for photochemical catalysis

Highly efficient aqueous artificial-light-harvesting systems (ALHSs) were successfully fabricated based on the supramolecular assembly of naphthalenyl-phenylacrylonitrile derivative (NPT), water-soluble pillar [5]arene (WP5), and three kinds of pigments (4,7-di(2-thienyl)-2,1,3-benzothiadiazole (DBT), Eosin Y (ESY), and sulforhodamine-101 (SR101)). The assembled ALHSs perform a high energy-transfer-efficiency (ΦETE) and antenna effect (90.9% and 40.6 for WP5⊃NPT-DBT, 81.5% and 39.1 for WP5⊃NPT-ESY as well as 71.3% and 38.4 for WP5⊃NPT-SR101), suggesting that the energy of WP5⊃NPT complex has been effectively transferred to pigment acceptors (DBT, ESY, and SR101). Notably, during the energy-transfer process of WP5⊃NPT-SR101 ALHS, a white light emission (ΦQY = 24.21%) could be achieved by tuning the molar-ratio of [NPT]/[SR101] to 250:1, which is close to that of natural light-harvesting system, displaying a promising application in simulating natural light-harvesting system. Furthermore, the WP5⊃NPT-SR101 ALHS was successfully utilized as nanoreactors to catalyze the free-radical dehalogenation reactions of 2-bromo-acetophenone, 2-bromo-4′-methylacetophenone, and 2-bromo-4′-nitroacetophenone with the yields of 92%, 90% as well as 95%, which realized the energy transformation from solar-energy to chemical-energy, displaying a potential prospect in the field of artificial photosynthesis systems.

A tunable artificial light-harvesting system based on host-guest interaction exhibiting ultrahigh antenna effect and narrowed emission band

The development of an artificial light-harvesting system with a high antenna effect (AE) and narrow full width at half-maxima (FWHM) has drawn significant interest. Herein, we constructed a highly efficient light-harvesting platform (WP5⊃G-SR101) in a water-based pillar[5]arene-induced self-assembly. In this light-harvesting system (LHS), the guest G is aggregation-induced emission (AIE) active and serves as an energy donor; SR101 is a kind of fluorescent dye that acts as an energy acceptor. The LHS exhibits remarkable energy-transfer efficiency, ultrahigh AE, and narrowed FWHM under relatively high donor/acceptor (D/A) ratios. Moreover, the emission of this artificial LHS is color-tunable, including a desirable white-light emission when D/A = 250/1. Our study herein not only provides an intelligent supramolecular strategy to prepare LHS with various advantages mentioned above but also shows great prospects in the area of new organic luminescent materials.

Supramolecular assemblies working as both artificial light-harvesting system and nanoreactor for efficient organic dehalogenation in aqueous environment

In this work, three artificial light-harvesting systems are constructed by a supramolecular approach in aqueous environment. The water-soluble bipyridinium derivatives (DPY1, DPY2, and DPY3) were self-assembled with cucurbit[7]uril (CB[7]) to form the host–guest DPY-CB[7] complexes, which can highly disperse in water as small nanoparticles. The excited DPY-CB[7] assemblies can transfer energy to the sulfo-rhodamine 101 (SR101) molecules at a high donor/acceptor ratio. With the help of hydrophobic cavity of CB[7], the DPY-CB[7] + SR101 systems can works as a nanoreactor for effective dehalogenation of α-bromoacetophenone and its derivatives in aqueous medium under white light irradiation. Such light-harvesting systems has greatly potential applications to realize some organic photocatalytic synthesis in aqueous environment.

An Artificial Light-Harvesting System with Controllable Efficiency Enabled by an Annulene-Based Anisotropic Fluid.

The development of controllable artificial light-harvesting systems based on liquid crystal (LC) materials, i.e., anisotropic fluids, remains a challenge. Herein, an annulene-based discotic LC compound 6 with a saddle-shaped cyclooctatetrathiophene core has been synthesized to construct a tunable light-harvesting platform. The LC material shows a typical aggregation-induced emission, which can act as a suitable light-harvesting donor. By loading Nile red (NiR) as an acceptor, an artificial light-harvesting system is achieved. Relying on the thermal-responsive self-assembling ability of 6 with variable molecular order, the efficiency of such 6-NiR system can be controlled by temperature. This light-harvesting system works sensitively at a high donor/acceptor ratio as 1000 : 1, and exhibits a high antenna effect (39.1) at a 100 : 1 donor/acceptor ratio. This thermochromic artificial light-harvesting LC system could find potential applications in smart devices employing soft materials.

Exciton Delocalization in a DNA-Templated Organic Semiconductor Dimer Assembly.

A chiral dimer of an organic semiconductor was assembled from octaniline (octamer of polyaniline) conjugated to DNA. Facile reconfiguration between the monomer and dimer of octaniline–DNA was achieved. The geometry of the dimer and the exciton coupling between octaniline molecules in the assembly was studied both experimentally and theoretically. The octaniline dimer was readily switched between different electronic states by protonic doping and exhibited a Davydov splitting comparable to those previously reported for DNA–dye systems employing dyes with strong transition dipoles. This approach provides a possible platform for studying the fundamental properties of organic semiconductors with DNA-templated assemblies, which serve as candidates for artificial light-harvesting systems and excitonic devices.

A novel polyelectrolyte-based artificial light-harvesting system for photocatalysis of cross-dehydrogenation coupling

Using polyelectrolyte materials, a simple and effective artificial light-harvesting system is constructed. This work promotes the application prospect of artificial light-harvesting system based on polyelectrolyte materials in photocatalysis.

An artificial light-harvesting system with sequential energy transfer for information dual encryption and anticounterfeiting

The artificial light-harvesting system (MPy1–ESY–SR101) with two-step sequential energy transfer constructed in this work serves as a privileged platform for multilevel data encryption and anticounterfeiting.

2D MOF nanosheets as an artificial light-harvesting system with enhanced photoelectric switching performance

The assembly of 2D MOF nanosheet with coumarin 6 afforded an efficient artificial light-harvesting system, which shows a high “on–off” photocurrent ratio up to 1000.

An atomically precise silver nanocluster for artificial light-harvesting system through supramolecular functionalization.

Designing an artificial light-harvesting system (LHS) with high energy transfer efficiency has been a challenging task. Herein, we report an atom-precise silver nanocluster (Ag NC) as a unique platform to fabricate the artificial LHS. A facile one-pot synthesis of [Cl@Ag16S(S-Adm)8(CF3COO)5(DMF)3(H2O)2]·DMF (Ag16) NC by using a bulky adamantanethiolate ligand is portrayed here which, in turn, alleviates the issues related to the smaller NC core designed from a highly steric environment. The surface molecular motion of this NC extends the non-radiative relaxation rate which is strategically restricted by a recognition site-specific supramolecular adduct with β-cyclodextrin (β-CD) that results in the generation of a blue emission. This emission property is further controlled by the number of attached β-CD which eventually imposes more rigidity. The higher emission quantum yield and the larger emission lifetime relative to the lesser numbered β-CD conjugation signify Ag16 ∩ β-CD2 as a good LHS donor component. In the presence of an organic dye (β-carotene) as an energy acceptor, an LHS is fabricated here via the Förster resonance energy transfer pathway. The opposite charges on the surfaces and the matched electronic energy distribution result in a 93% energy transfer efficiency with a great antenna effect from the UV-to-visible region. Finally, the harvested energy is utilized successfully for efficient photocurrent generation with much-enhanced yields compared to the individual components. This fundamental investigation into highly-efficient energy transfer through atom-precise NC-based systems will inspire additional opportunities for designing new LHSs in the near future.

Efficient artificial light-harvesting systems with gel properties formed by ion recognition

A novel supramolecular gelator (G3) exhibited excellent selectivity toward Mg2+ as well as showed excellent gelation abilities. Meanwhile, an efficient artificial light-harvesting system has been constructed between G3@Mg-sol or G3@Mg-gel and RhB.

Room-temperature Barbier single-atom polymerization induced emission as a versatile approach for the utilization of monofunctional carboxylic acid resources

Barbier polymerization is realized at room-temperature with single-atom polymerization and polymerization-induced emission characteristics, which exhibits capability on sensitive explosive detection and artificial light-harvesting system fabrication.