“Supergold” is a very powerful gender-neutral warrior with superpowers who fights against cancer! The warrior's golden armor and sword represent the pharmacological power of the gold atom. Engraved on the shield, the gold-thiosemicarbazones molecules are the warrior's coat of arms. Supergold selectively destroys different cancer cells. More information can be found in the Research Article by Esteban Rodríguez-Arce, María Contel, and co-workers.
The cover picture compares the structure of calcined (left) and non-calcined (right) rutile TiO2 doped with a molecule NA. The calcination process enlarges the pores in TiO2, reducing its surface area and hydrogen production efficiency under visible light. The “sad face” symbolizes the damaged pore structure. Conversely, doping TiO2 with NA without high-temperature calcination forms a covalent bond, resulting in smaller pores, larger surface area, and improved hydrogen production efficiency. The “smiley face” represents the structurally intact TiO2 hybrid material. More information can be found in the Research Article by Jianwei Li, Chunman Jia, and co-workers.
Four binuclear Au(III) complexes have been synthetized using non-chelating bidentate ligands. When a chelating ligand was used, a digold salt was obtained resulting from the chelation of the diphosphine ligand on one Au moiety and a [(C^C)AuCl2]− anion. The complexes appeared strongly emissive in solid state and the digold salt presented anticancer activities in the nanomolar range with no modification of the [(C^C)Au(P^P)]+ in the presence of biomolecules.
A series of four binuclear complexes of general formula [(C^C)Au(Cl)(L^L)(Cl)Au(C^C)], where C^C is 4,4’-diterbutylbiphenyl and L^L is either a bridging diphosphine or 4,4’-bipyridine, are synthetized with 52 to 72 % yield and structurally characterized by X-ray diffraction. The use of the chelating 1,2-diphenylphosphinoethane ligand in a 1 : 2 (P^P):Au stoichiometry leads to the near quantitative formation of a gold double-complex salt of general formula [(C^C)Au(P^P)][(C^C^)AuCl2]. The compounds display long-lived yellow-green phosphorescence with λem in the range of 525 to 585 nm in the solid state with photoluminescence quantum yields (PLQY) up to 10 %. These AuIII complexes are tested for their antiproliferative activity against lung adenocarcinoma cells A549 and results show that compounds 2 and 5 are the most promising candidates. The digold salt 5 shows anticancer activity between 66 and 200 nM on the tested cancer cell lines, whereas derivative 2 displays concentration values required to reduce by 50 % the cell viability (IC50) between 7 and 11 μM. Reactivity studies of compound 5 reveal that the [(C^C)Au(P^P)]+ cation is stable in the presence of relevant biomolecules including glutathione suggesting a structural mechanism of action.
![Host-Guest Complexes of Pillar[5]arene as Components for Supramolecular Light-Harvesting Systems with Tunable Fluorescence](https://onlinelibrary.wiley.com/cms/asset/3161adbc-ec10-4376-adcb-240a9b139634/cplu202300431-toc-0001-m.png)
A supramolecular light-harvesting system with high donor/acceptor ratio has been constructed from pillar[5]arene-based host-guest complex in water. The system exhibits tunable fluorescence emission and can be used as fluorescent ink for information encryption.
A guest molecule containing a short alkyl spacer between the tetraphenylethylene group and the methylpyridinium group was designed and synthesized. After complexation with a water-soluble pillar[5]arene, the resulting host-guest complex can further self-assemble into fluorescence-emitting nanoparticles in water. By loading a commercially available dye Rhodamine 6G into the nanoparticles, an efficient artificial light-harvesting system with high donor/acceptor ratios (>400/1) was successfully constructed. The obtained systems show considerable antenna effects with values of more than 10 times. The system also exhibits tunable fluorescence emission behavior and can be used as a fluorescent ink for information encryption.
The cover feature image shows the sublimation process of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene on a concave surface of a spherical glass substrate, on which the branched hollow crystals are densely produced. These crystals can make the roles in moving and releasing the minute object during the bending behaviors by the irradiation with UV light according to the number and size of units of the hollow structures in them, which depend on the substrate curvature. More information can be found in the Research Article by Seiya Kobatake and co-workers.
The sublimation process where the thin films of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene are formed on a concave surface of the spherical glass substrate, accompanying the movement of boundaries between the thin film domains under the higher relative humidity condition, leads to the fabrication of the hollow crystals having the highly branched shapes.
We report the fabrication of hyperbranched hollow crystals of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene on a concave surface of the spherical glass substrate by sublimation and their practical photomechanical behaviors. The number of units of the branched structure of the hollow crystals composed of this compound is proportional to the substrate curvature of the substrate. Compared with the sublimation process of the same compound on the flat glass substrate, two kinds of the thin film domains are generated separately in the center and around the edge of the spherical glass substrate. Especially under the high relative humidity condition, the boundaries between these thin film domains move gradually around the edge through the center during as long as 6 h of sublimation time so that the hyperbranched hollow crystals are densely produced on the entire surface of the substrate. These hyperbranched hollow crystals can be prepared with the highly ordered molecular packing due to the very slow formation process of the crystalline walls of the hollow structures. Furthermore, the photo-induced bending behaviors in the few- and highly-branched hollow crystals have the practical roles in moving and bending the minute objects according to their characteristics of these branched shapes.
Despite piezoelectric materials have a long history of application, piezoelectric catalysis has continued to be a hot topic in recent years. Flexible piezoelectric materials have just emerged in recent years due to their versatility and designability. In this paper, we review the recent advances in flexible piezoelectric materials for catalysis, discuss the fundamentals of the catalytic properties of composite materials, and detail the typical structures of these materials. We pay special attention to the types of filler in flexible piezoelectric composites, their role and the interaction between the particles and the flexible substrate. Notable examples of flexible piezoelectric materials for organic pollutants degradation, enhanced piezo-photocatalysis and antibacterial are also presented. Finally, we present key issues and future prospects for the development of flexible piezoelectric catalysts.
Photo-lipids: trans or cis ? The cover image represents AFM micrographs of phase-separated supported lipid bilayers containing an azobenzene-derived photo-lipid (top & bottom rows). The light-induced isomerization of the azobenzene allows remodeling of the shape of membrane domains. When the photo-lipid adopts a cis-configuration, a fluidification of the membrane is observed as small liquid-disordered (ld) domains (brown) are formed inside the liquid-ordered (lo) phase (gold). In the trans-configuration, the area of the lo domains becomes prominent over that of the ld phase, indicating an increase of membrane order. In the presence of a protein (middle row), cis-isomerization triggers the formation of domains enriched with protein clusters. More information can be found in the Review by Larissa Socrier and Claudia Steinem.
The first chiral gold (III) amphiphile enables chiral supramolecular assembly in aqueous media, confirmed by circular dichroic and electron microscopy, with potential supramolecular helicity enhancement controlled by packing parameters of the amphiphilic design. The resulting chiral supramolecular assembly shows good cytocompatibility.
Gold (III) cyclometalated based amphiphiles in aqueous media have been revealed with excellent supramolecular transformations to external stimuli to open new pathways for soft functional material fabrications. Herein, we report a new chiral cyclometalated gold (III) amphiphile (GA) assembling into lamellar nanostructures in aqueous media confirmed with transmission electron microscopy (TEM). Counterion exchange with D-, L-, or racemic-camphorsulfonates features the significant supramolecular helicity enhancements, enabling transformations of GA from lamellar structure to vesicles and to nanotubes with multi-equivalents of counterion. The limited cytotoxicity of GA in aqueous media exhibits good biocompatibility.
An optical control: The structure and organization of eukaryotic plasma membranes has been widely discussed since the introduction of the fluid mosaic model. Light-sensitive lipids were recently introduced in artificial lipid systems and cells to study lipid-lipid and lipid-protein interactions. Here, we review the application of these probes to investigate membrane properties and lateral organization.
Biological membranes are described as a complex mixture of lipids and proteins organized according to thermodynamic principles. This chemical and spatial complexity can lead to specialized functional membrane domains enriched with specific lipids and proteins. The interaction between lipids and proteins restricts their lateral diffusion and range of motion, thus altering their function. One approach to investigating these membrane properties is to use chemically accessible probes. In particular, photo-lipids, which contain a light-sensitive azobenzene moiety that changes its configuration from trans- to cis- upon light irradiation, have recently gained popularity for modifying membrane properties. These azobenzene-derived lipids serve as nanotools for manipulating lipid membranes in vitro and in vivo. Here, we will discuss the use of these compounds in artificial and biological membranes as well as their application in drug delivery. We will focus mainly on changes in the membrane's physical properties as well as lipid membrane domains in phase-separated liquid-ordered/liquid-disordered bilayers driven by light, and how these changes in membrane physical properties alter transmembrane protein function.