The exploitation of new materials for adsorptive separation of industrially important hydrocarbons is of great importance in both scientific research and petrochemical industry. Nonporous adaptive ...crystals (NACs) as a robust class of synthetic materials have drawn much attention during the past five years for their superior performance in adsorption and separation. Pillararenes are the main family of macrocyclic arenes used for NACs construction, where the structure–function relationship has been intensively studied. In the past two years, some emerging types of synthetic macrocyclic arenes have been successfully brought into this research field, showing the gradual enrichment and diversification of NACs materials. This Minireview summarizes the recent advances of synthetic macrocycle‐based NACs, which are categorized by various practical applications in molecular separation. Besides, NACs‐based vapochromic supramolecular systems are also discussed. Finally, future perspectives and challenges of NACs are given. We envisage that this Minireview will be a useful and timely reference for those who are interested in new molecular and supramolecular crystals for storage and separation applications.
This Minireview describes the recent advances of synthetic macrocycle‐based nonporous adaptive crystals for molecular separation and vapochromic application.
Haloalkanes are important chemicals in synthetic chemistry and petrochemical industry, but the separation of their isomers is a big hurdle. Herein, we report a facile energy‐efficient adsorptive ...separation strategy using a new class of nonporous adaptive crystals based on leaning pillar6arene. Desolvated perethylated leaning pillar6arene crystals (EtLP6) with interesting nonporous character show a preference for 1‐bromoalkane isomers over 2‐bromoalkane isomers. EtLP6 is capable of separating 1‐bromopropane, 1‐bromobutane, and 1‐bromopentane from the corresponding 1:1 (v/v) mixtures of 1/2‐positional isomers with purities from 89.6 % to 96.3 % in only one adsorption cycle. The selectivity is endowed by the different host–guest binding modes and different stabilities of EtLP6 crystalloids loaded with 1‐ and 2‐positional isomers. Significantly, the guest–adsorbed assemblies are highly stable at room temperature and EtLP6 can be reused many times without any decrease in performance.
The separation of haloalkane isomers is of high practical value in both synthetic chemistry and petrochemical industry. Herein, a simple‐operating and energy‐efficient separation method by using nonporous leaning towerarene crystals to separate bromoalkane isomers is provided.
Synthetic macrocycles have served as principal tools for supramolecular chemistry, have greatly extended the scope of organic charge transfer (CT) complexes, and have proved to be of great practical ...value in the solid state during the past few years. In this Minireview, we summarize the research progress on the macrocycle‐based crystalline supramolecular assemblies primarily driven by intermolecular CT interactions (a.k.a. macrocycle‐based crystalline CT assemblies, MCCAs for short), which are classified by their donor–acceptor (D‐A) constituent elements, including simplex macrocyclic hosts, heterogeneous macrocyclic hosts, and host–guest D‐A pairs. Particular attention will be focused on their diverse functions and applications, as well as the underlying CT mechanisms from the perspective of crystal engineering. Finally, the remaining challenges and prospects are outlined.
This Minireview highlights the advancements in the field of macrocycle‐based crystalline charge‐transfer assemblies, including their preparation, structures, and diverse supramolecular functions and applications, such as vapochromic behavior and supramolecular tessellations, arising from the CT state. Future perspectives and challenges of this emerging research field are also presented.
Incorporating synthetic macrocycles with unique structures and distinct conformations into conjugated macrocycle polymers (CMPs) can endow the resulting materials with great potentials in gas uptake ...and pollutant adsorption. Here, four CMPs (CMP‐n, n=1–4) capable of reversibly capturing iodine and efficiently separating carbon dioxide are constructed from per‐triflate functionalized leaning tower6arene (LT6‐OTf) and 2biphenyl‐extended pillar6arene (BpP6‐OTf) via Pd‐catalyzed Sonogashira–Hagihara cross‐coupling reaction. Intriguingly, owing to the appropriate cavity size of LT6‐OTf and the numerous aromatic rings in the framework, the newly designed CMP‐4 possesses an outstanding I2 affinity with a large uptake capacity of 208 wt % in vapor and a great removal efficiency of 94 % in aqueous solutions. To our surprise, with no capacity to accommodate nitrogen, CMP‐2 constructed from BpP6‐OTf is able to specifically capture carbon dioxide at ambient conditions.
Four catcher‐type conjugated macrocycle polymers (CMP‐n, n=1–4) have been designed and synthesized successfully, exhibiting interesting application in CO2 and I2 uptake. The CMP‐2 is able to capture CO2 with excellent selectivity and the CMP‐4 is capable of adsorbing iodine with outstanding capacity.
In the paper, we compute the correlation functions in 2D
N
= (1
,
1) and
N
= (2
,
2) superconformal field theories with
T
T
¯
deformation up to the first order of the deformation in terms of ...perturbation theory. With the help of superconformal Ward identity in
N
= (1
,
1) and
N
= (2
,
2) theories and careful regularization, the correlation functions in the deformed theory can be obtained up to the first order perturbation. This study is the extension from previous bosonic
T
T
¯
deformation to the supersymmetric one.
Ferroptosis is a recently defined form of cell death with the involvement of iron and reactive oxygen species (ROS), which is distinct from apoptosis, autophagy and other forms of cell death. ...Emerging evidence suggested that iron accumulation and lipid peroxidation can be discovered in various neurological diseases, accompanied with reduction of glutathione (GSH) and glutathione peroxidase 4 (GPX4). In addition, ferroptotic inhibitors have been shown to protect neurons, and recover the cognitive function in disease animal models. This review summarizes the mechanisms underlying ferroptosis and reviews the contributions of ferroptosis in neurodegenerative diseases (i.e. Alzheimer’s disease and Parkinson’s disease), traumatic brain injury, as well as hemorrhagic and ischemic stroke, to provide the current understanding of this novel form of cell death in neurological disorders.
Desymmetrized Leaning Pillar[6]arene Wu, Jia‐Rui; Mu, Anthony U.; Li, Bao ...
Angewandte Chemie International Edition,
July 26, 2018, Volume:
57, Issue:
31
Journal Article
Peer reviewed
In this work, a novel version of macrocyclic arenes, namely leaning pillar6arenes, was discovered and it can be considered as a tilted version of a pillar6arene with two hydroxy/alkoxy ...functionalities removed. Through a facile two‐step synthetic approaches, in conjunction with a diversity of post‐modification possibilities, a series of leaning pillar6arenes, with good cavity adaptability and enhanced guest‐binding capability, was synthesized, and their self‐assembly in single‐crystal states is presented. DFT calculations demonstrated that the lower rotational barrier of unsubstituted phenylene rings, the uneven electron density centered at the leaning phenyl rings, and the polarization effect along the edge generated by the hydrogen‐bond‐induced orientation of hydroxy groups greatly affected the host‐guest properties, and meanwhile provided an intuitive explanation for the pillar‐like and rigid structure of traditional pillar6arenes. Significantly, the crystal structure of cyclo‐oligomeric quinone was obtained by direct oxidation of leaning pillar6arenes.
A lean‐to: A series of backbone‐desymmetrized pillararenes, namely leaning pillar6arenes, has been designed and successfully synthesized. They exhibit interesting three‐dimensional packing structures and enhanced host‐guest properties.
A
bstract
In the holographic framework, we argue that the partial entanglement entropy (PEE) can be explicitly interpreted as the component flow flux in a locking bit thread configuration. By ...applying the locking theorem of bit threads, and constructing a concrete locking scheme, we obtain a set of uniquely determined component flow fluxes from this viewpoint, and successfully derive the PEE proposal and its generalized version in the multipartite cases. Moreover, from this perspective of bit threads, we also present a coherent explanation for the coincidence between the BPE (balanced partial entanglement)/EWCS (entanglement wedge cross section) duality proposed recently and the EoP (entanglement of purification)/EWCS duality. We also discuss the issues implied by this coincident between the idea of the PEE and the picture of locking thread configuration.
In order to overcome the limitations of supramolecular organic cages for their incomplete accessibility of active sites in the solid state and uneasy recyclability in liquid solution, herein a ...nitrogen‐rich organic cage is rationally linked into framework systems and four isoreticular covalent organic frameworks (COFs), that is, Cage‐TFB‐COF, Cage‐NTBA‐COF, Cage‐TFPB‐COF, and Cage‐TFPT‐COF, are successfully synthesized. Structure determination reveals that they are all high‐quality crystalline materials derived from the eclipsed packing of related isoreticular two‐dimensional frameworks. Since the nitrogen‐rich sites usually have a high affinity toward iodine species, iodine adsorption investigations are carried out and the results show that all of them display an enhancement in iodine adsorption capacities. Especially, Cage‐NTBA‐COF exhibits an iodine adsorption capacity of 304 wt%, 14‐fold higher than the solid sample packed from the cage itself. The strong interactions between the nitrogen‐rich sites and the adsorbed iodine species are revealed by spectral analyses. This work demonstrates that, utilizing the reticular chemistry strategy to extend the close‐packed supramolecular organic cages into crystalline porous framework solids, their inherent properties can be greatly exploited for targeted applications.
Linking supramolecular organic cages with triple‐symmetric organic connectors, covalent organic frameworks (COFs) are successfully constructed. Obvious enhancement in iodine uptake up to 14 times higher than that of the solid packed by the cage itself is achieved, demonstrating that extending the close‐packed supramolecular organic cages into crystalline porous frameworks can be employed for targeted applications.
New strategies that can simultaneously detect and remove highly toxic environmental pollutants such as heavy metal ions are still in urgent need. Herein, through supramolecular host–guest ...interactions, a fluorescent supramolecular polymer has been facilely constructed from a newly designed 2biphenyl-extended pillar6arene equipped with two thymine sites as arms (H) and a tetraphenylethylene (TPE)-bridged bis(quaternary ammonium) guest (G) with aggregation-induced emission (AIE) property. Interestingly, supramolecular assembly-induced emission enhancement (SAIEE) could be switched on upon addition of Hg2+ into the above-mentioned supramolecular polymer system to generate spherical-like supramolecular nanoparticles, due to the restriction of intramolecular rotation (RIR)-related AIE feature of G. Significantly, this supramolecular polymer with integrated modalities has been successfully used for real-time detection and removal of toxic heavy metal Hg2+ ions from water with quick response, high selectivity, and rapid adsorption rates, which could be efficiently regenerated and recycled without any loss via a simple treatment with Na2S. The newly developed supramolecular polymer system combines the inherent rigid and spacious cavity of novel extended-pillarene host with the AIE characteristics of TPE-based guest, suggesting a great potential in the treatment of heavy metal pollution and environmental sustainability.
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