2D perovskite is an organic–inorganic hybrid material with good photoelectric properties, generally prepared by using organic groups as isolation molecules. In this study, using manganese chloride ...and potassium halide as raw materials, all‐inorganic 2D lead‐free perovskites are prepared by the Bridgeman melting and cooling method. Different from the 2D perovskites synthesized by organic spacer molecules, the prepared all‐inorganic 2D perovskites have smaller layer spacings and good crystallization performance due to the use of potassium halide as spacer molecules. They are direct bandgap semiconductors and their energy bandgaps are tuned by the different types of potassium halides. High degree orientation crystal thin films with (001) lattice plane parallel to silicon wafer substrate are prepared by double‐source evaporation. The physical morphology of the films is characterized by grazing angle X‐ray diffraction, transmission electron microscopy, and electron diffraction. The field effect transistors prepared from these 2D films show excellent electronic characteristics. The mobility of the optimized device is ≈24 cm2 v−1 s−1 and the on/off ratio reaches 105. This study reveals the potential of lead‐free manganese 2D perovskite as a high‐performance perovskite field effect transistor.
The successfully synthesized lead‐free 2D manganese‐based (Mn‐based) all‐inorganic perovskite exhibits high pure crystal with a high carrier transport performance. After optimization, the maximum hole mobility of 2D perovskite field effect transistor (PeFETs) is 24 cm2 V−1 s−1, and the on/off ratio is 105 surpassing all reported PeFETs.
Herein, we describe how to utilize dihydrogen bond interactions to achieve alkane recognition and hexane isomer separation. A series of metallacycles based on carborane backbones are presented ...herein, revealing interdependent B–Hδ−···Hδ+–C proton–hydride interactions. The metallacycles take advantage of these dihydrogen bond interactions for the separation of hexane isomers. We show that the metallacycle 3a, bearing 1,4-di(4-pyridyl)benzene (DPB), can produce n-hexane with a purity of >99% in a single adsorption–desorption cycle from an equimolar mixture of all five isomers of hexane. The isomers 2-methylpentane and 3-methylpentane can be selectively absorbed by metallacycle 4a, which bears 1,2-di(4-pyridyl)ethylene (DPE). The size of the metallacycle, C–H···π interactions, and particularly B–Hδ−···Hδ+–C interactions are the main forces governing the extent of hexane recognition. This work provides a promising principle for the design of supramolecular coordination complexes (SCCs) for the separation of alkanes.
Herein, we describe how to utilize stacking interactions to achieve selective supramolecular transformation and molecular Borromean rings (BRs). By using a dinuclear naphthalenediimide (NDI)-based ...Cp*Rh acceptor and linear bipyridyl ligands, organometallic rectangles featuring dynamic behavior have been constructed. Unique discrete aromatic stacking arrays were formed by inducing pyrene units as guest molecules. The topology of the BRs was realized by the use of a strategically chosen ligand which was capable of participating in D–A interactions and hydrogen bonding, as evidenced from single-crystal X-ray analysis and computational studies. These self-assembly processes underline the advantages of dynamic bonding and π–π stacking interactions, and serve to illustrate a new approach to generating structurally and topologically nontrivial supramolecular architectures.
A Cp*‐Rh based D‐shaped binuclear metallacycle and a template‐free molecular Borromean ring (BR) were obtained in high yield using the semi‐rigid thioether dipyridyl ligand ...1,4‐bis(pyridin‐4‐ylthio)methylbenzene (Bptmb). The topological transformation from a binuclear metallacycle and a BR to tetranuclear metallacycles was realized via the controlled oxidation of thioethers. The strategy used in this work can be regarded as a new form of stimuli‐responsive post‐synthesis modification (PSM).
The controlled oxidation from thioether to sulfoxide and sulfone groups is a new post‐synthetic modification to achieve the stimuli‐responsive structural transformation from the molecular Borromean ring to tetranuclear metallacycles.
In contrast to conventional stepwise synthesis of molecular Borromean rings, a self‐assembly synthetic method which proceeds without the aid of a template has been developed. In the formation of ...molecular rectangles, by adjustment of the long‐arm length of the rectangles, a series of size‐dependent Borromean‐link frameworks were constructed. Both the shortest length of two arms and the relative proportion of the length of the long arm to that of the short arm play a key role in the formation of Borromean rings. DFT calculations were used to provide theoretical support for the formation of discrete interlocked frameworks.
A (Borro)mean business: For chemists, molecular Borromean rings represent a formidable synthetic challenge. Different from their stepwise synthesis with the aid of a well‐known driving force, a self‐assembly method associated with the formation of molecular rectangles is described. DFT calculations were used to provide theoretical support for the formation of these species.
A stepwise self‐assembly protocol has been used to synthesize 2‐ and 3catenanes. Firstly, binuclear Cp*Rh/Ir‐directed (Cp*=pentamethylcyclopentadienyl) pseudorotaxanes were prepared through ...self‐assembly, driven by donor–acceptor interactions between electron‐deficient naphthalenediimide (NDI) units and an electron‐rich crown ether. Subsequently, the pre‐organized pseudorotaxanes were applied as tectons for self‐assembly of 2‐ and 3catenanes by combination with very simple linkers. The structures of the catenanes were confirmed by NMR spectroscopy, ESI mass spectrometry, single‐crystal X‐ray diffraction analysis, and elemental analysis.
Interlocked compounds: Donor–acceptor pseudorotaxanes were prepared through Cp*Rh‐ or Cp*Ir‐directed (Cp*=pentamethylcyclopentadienyl) self‐assembly. The pre‐organized binuclear catenaned complexes were used as versatile tectons for 2‐ and 3catenanes.
A series of Cp*Rh‐based discrete architectures was constructed by selecting four ether bipyridyl ligands and three half‐sandwich rhodium(III) bimetallic construction units, respectively. This study ...demonstrates a strategy for making the transition from a binuclear D‐shaped ring to a tetranuclear 2catenane by adjusting the length of bipyridyl ligands. In addition, changing the position on the naphthyl group of the bipyridyl ligand from 2,6‐ to 1,5‐position substitution can realize the selective synthesis of 2catenane and Borromean rings under similar conditions. The above‐mentioned constructions have been determined via X‐ray crystallographic analysis, detailed NMR techniques, electrospray ionization‐time‐of‐flight/mass spectrometry analysis, and elemental analysis.
A series of discrete Cp* Rh‐based structures were constructed by selecting four ether bipyridyl ligands and three half‐sandwich rhodium (III) bimetallic construction units. This study demonstrates a strategy to convert a binuclear D‐shaped to a 2catenane by changing the length of bridged ligands. Selective synthesis of 2catenane and molecular Borromean rings can be achieved under similar conditions.
Over the past decades, molecular knots and links have captivated the chemical community due to their promising mimicry properties in molecular machines and biomolecules and are being realized with ...increasing frequency with small molecules. Herein, we describe how to utilize stacking interactions and hydrogen-bonding patterns to form trefoil knots, figure-eight knots and 2catenanes. A transformation can occur between the unique trefoil knot and its isomeric boat-shaped tetranuclear macrocycle by the complementary concentration effect. Remarkably, the realization and authentication of the molecular figure-eight knot with four crossings fills the blank about 4
knot in knot tables. The 2catenane topology is obtained because the selective naphthalenediimide (NDI)-based ligand, which can engender favorable aromatic donor-acceptor π interactions due to its planar, electron-deficient aromatic surface. The stacking interactions and hydrogen-bond interactions play important roles in these self-assembly processes. The advantages provide an avenue for the generation of structurally and topologically complex supramolecular architectures.
Doped nanoparticles (especially bimetal doped nanoparticles) have attracted extensive interest not only for fundamental scientific research but also for application purposes. However, their ...indefinite composition (structure) and broad distribution hinder an insightful understanding of the interaction between these invasive metals in bimetal doped nanoparticles. Fortunately, atom-precise bimetal doped ultrasmall nanoparticles (nanoclusters) provide opportunities to obtain such insights. However, atom-precise trimetal nanoclusters and their structures have rarely been reported. Here, we successfully dope thiolated Au25 nanoclusters with Hg and Ag successively by using a biantigalvanic reduction method. We then fully characterize the as-obtained trimetal nanoclusters using multiple techniques (including single-crystal X-ray crystallography), and we demonstrate that the mercury and silver dopings exhibit not only a synergistic but also a counteractive influence on some of the physicochemical properties of Au25.
Controlling the dopant type, number, and position in doped metal nanoclusters (nanoparticles) is crucial but challenging. In the work described herein, we successfully achieved the mono-cadmium ...doping of Au25 nanoclusters, and revealed using X-ray crystallography in combination with theoretical calculations that one of the inner-shell gold atoms of Au25 was replaced by a Cd atom. The doping mode is distinctly different from that of mono-mercury doping, where one of the outer-shell Au atoms was replaced by a Hg atom. Au24Cd is readily transformed to Au24Hg, while the reverse (transformation from Au24Hg to Au24Cd) is forbidden under the investigated conditions.
![Donor–Acceptor [2]‐ and [3]...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0947-6539/small "Donor–Acceptor [2]‐ and [3]Catenanes Assembled from Versatile Pre‐Organized CpRh/Ir‐Directed Pseudorotaxane Tectons")
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