Superstructured Carbon with Enhanced Kinetics for Zinc-Air Battery and Self-Powered Overall Water Splitting.

The present study proposes a novel engineering concept for the customization of functionality and construction of superstructure to fabricate 2D monolayered N-doped carbon superstructure electrocatalysts decorated with Co single atoms or Co2 P nanoparticles derived from 2D bimetallic ZnCo-ZIF superstructure precursors. The hierarchically porous carbon superstructure maximizes the exposure of accessible active sites, enhances electron/mass transport efficiency, and accelerates reaction kinetics simultaneously. Consequently, the Co single atoms embedded N-doped carbon superstructure (Co-NCS) exhibits remarkable catalytic activity toward oxygen reduction reaction, achieving a half-wave potential of 0.886 V versus RHE. Additionally, the Co2 P nanoparticles embedded N-doped carbon superstructure (Co2 P-NCS) demonstrates high activity for both oxygen evolution reaction and hydrogen evolution reaction, delivering low overpotentials of 292 mV at 10 mA cm-2 and 193 mV at 10 mA cm-2 respectively. Impressively, when employed in an assembled rechargeable Zn-air battery, the as-prepared 2D carbon superstructure electrocatalysts exhibit exceptional performance with a peak power density of 219 mW cm-2 and a minimal charge/discharge voltage gap of only 1.16 V at 100 mA cm-2 . Moreover, the cell voltage required to drive an overall water-splitting electrolyzer at a current density of 10 mA cm-2 is merely 1.69 V using these catalysts as electrodes.

SHNE: Semantics and Homophily Preserving Network Embedding.

Graph convolutional networks (GCNs) have achieved great success in many applications and have caught significant attention in both academic and industrial domains. However, repeatedly employing graph convolutional layers would render the node embeddings indistinguishable. For the sake of avoiding oversmoothing, most GCN-based models are restricted in a shallow architecture. Therefore, the expressive power of these models is insufficient since they ignore information beyond local neighborhoods. Furthermore, existing methods either do not consider the semantics from high-order local structures or neglect the node homophily (i.e., node similarity), which severely limits the performance of the model. In this article, we take above problems into consideration and propose a novel Semantics and Homophily preserving Network Embedding (SHNE) model. In particular, SHNE leverages higher order connectivity patterns to capture structural semantics. To exploit node homophily, SHNE utilizes both structural and feature similarity to discover potential correlated neighbors for each node from the whole graph; thus, distant but informative nodes can also contribute to the model. Moreover, with the proposed dual-attention mechanisms, SHNE learns comprehensive embeddings with additional information from various semantic spaces. Furthermore, we also design a semantic regularizer to improve the quality of the combined representation. Extensive experiments demonstrate that SHNE outperforms state-of-the-art methods on benchmark datasets.

Electrocatalytic water oxidation enabling the highly selective oxidation of styrene to benzaldehyde.

An electrooxidation strategy mediated by reactive oxygen species is proposed to realize the transformation of styrene to benzaldehyde on a Pt anode, with a high selectivity of ca. 89% and faradaic efficiency of 28.8%. Isotopic labelling, electron paramagnetic resonance and radical scavenging experiments revealed that OH˙ and O2-˙ species, formed in situ via anodic water oxidation, play a crucial role in the selective formation of benzaldehyde.

Outcomes of first-line anti-PD-L1 blockades combined with brain radiotherapy for extensive-stage small-cell lung cancer with brain metastasis.

INTRODUCTION: Anti-programmed cell death-ligand 1 (Anti-PD-L1) blockades have become the first-line treatment of extensive-stage small-cell lung cancer (ES-SCLC) from CASPIAN and IMpower133 trials. SCLC has a high incidence of brain metastasis (BM) and brain radiotherapy (BRT) is the main local treatment method, but there is limited data on the BRT-immunotherapy scheme. The aim of the retrospective study is to investigate the clinical efficacy and safety of the first-line anti-PD-L1 blockades combined with BRT in ES-SCLC with BM. METHODS: Patients with newly diagnosed ES-SCLC with baseline BMs at Shandong Cancer Hospital and Research Institute between 2017 and 2021 were selected. Patients were divided into the anti-PD-L1+BRT group and BRT group. We also assessed the leukoencephalopathy in both groups. RESULTS: A total of 46 patients were selected. Fifteen were divided into anti-PD-L1+BRT group and 31 to BRT group. The median overall survival (OS) was not reached (NR) vs 15.9 m (P = 0.172). Progression-free survival (PFS) was numerically prolonged with anti-PD-L1 blockades, but the significance was not reached (median: 9.4 m vs 7.4 m, P = 0.362). The median intracranial PFS was not improved, neither (median: 8.2 m vs 8.9 m, P = 0.620). Objective response rate (ORR) in the two groups was 73.33% vs 77.42% (P = 0.949) and disease control rate (DCR) was both 100%. Intracranial ORR and DCR were 53.33% vs 70.97% (P = 0.239) and 73.33% vs 80.65% (P = 0.855), respectively. There was no significant difference in leukoencephalopathy incidence between the two groups. CONCLUSION: The combination of first-line anti-PD-L1 blockades with BRT did not confer a significant survival benefit in ES-SCLC with BM, without enhancing cranial neurotoxicity.

s-Tetrazine-Bridged Photochromic Aromatic Framework Material.

Integrating fluorescent chromophores in aromatic frameworks could not only prevent aggregation-induced quenching caused by the π-π stacking interaction between the chromophore components but also confer new fluorescence properties. Herein, we report the fabrication of s-tetrazine-bridged aromatic frameworks TzAF by the incorporation of the smallest aromatic fluorophore, s-tetrazine (Tz), into the skeleton of a tetrahedrally connected lattice of aromatic frameworks. The thin films of TzAF coated on silica gel plates were found to exhibit reversible photoswitching fluorescence characteristics under alternate UV and visible-light irradiations with excellent fluorescence stability and high on/off contrast. The repeatable "on/off"fluorescence photoswitchability of the TzAF thin films was mechanistically attributed to light-induced reversible transformation between TzAF's neutral and radical states.

ortho-Functionalization of Pillar[5]arene: An Approach to Mono-ortho-Alkyl/Aryl-Substituted A1/A2-Dihydroxypillar[5]arene.

Despite the fact that the rim and lateral functionalizations of pillar[n]arenes have been well explored, ortho-functionalization has rarely been realized. In this work, we report a facile method of introducing a single functionality ortho to the hydroxyl group in A1/A2-dihydroxypillar[5]arene via a Grignard addition to pillar[4]arene[1]quinone followed by a dienone-phenol rearrangement. The described ortho-alkylation/arylation method allowed formation of various mono ortho-alkyl/aryl-substituted A1/A2-dihydroxypillar[5]arenes previously difficult to obtain.

Electrochemical Reduction of CO2 to HCOOH over Copper Catalysts.

Although great progress has been made in the field of electrochemical CO2 reduction reaction (eCO2RR), inducing product selectivity is still difficult. We herein report that a thiocyanate ion (SCN-) switched the product selectivity of copper catalysts for eCO2RR in an H-cell. A cuprous thiocyanate-derived Cu catalyst was found to exhibit excellent HCOOH selectivity (faradaic efficiency = 70-88%) over a wide potential range (-0.66 to -0.95 V vs RHE). Furthermore, it was revealed that the formation of CO and C2H4 over commercial copper electrodes could be dramatically suppressed with the presence of SCN-, switching to HCOOH. Density functional theory calculations disclosed that SCN- made the formation of HCOO* easier than COOH* on Cu (211), facilitating the HCOOH generation. Our results provide a new insight into eCO2RR and will be helpful in the development of cheap electrocatalysts for specific utilization.

Pillar[5]arene-Derived endo-Functionalized Molecular Tube for Mimicking Protein-Ligand Interactions.

Artificial tubular molecular pockets bearing polar functionalities on their inner surface are useful model systems for understanding the mechanisms of protein-ligand interactions in living systems. We herein report a pillar[5]arene-derived molecular tube, [P4-(OH)BPO], whose endo conformational isomer endo-[P4-(OH)BPO] possesses an inwardly pointing hydrogen-bond (H-bond) donor (OH) in its deep cavity and a strong H-bond acceptor (C═O) on its predominantly hydrophobic inner surface, rendering it a perfect protein binding pocket mimetic. A fragment-based drug design model was established using endo-[P4-(OH)BPO] and a library of various shape-complementary fragment ligands (1-38). On the basis of the binding affinity data for "fragment-pocket" complexes G⊂endo-[P4-(OH)BPO] (G = 1-38), two rationally designed "lead molecules" (39 and 40) were identified as being able to enhance binding affinity significantly by forming H-bonds with both the donor and acceptor of endo-[P4-(OH)BPO]. The described work opens new avenues for developing pillar[n]arene-derived protein binding pocket-mimetic systems for studies of protein-ligand interactions and mechanisms of enzymatic reactions.

Highly Branched Pillar[5]arene-Derived Porous Aromatic Frameworks (PAFs) for Removal of Organic Pollutants from Water.

The adsorption process is widely used for the treatment of wastewater containing organic pollutants. We fabricated highly branched pillar[5]arene-based porous aromatic frameworks (PAFs), PAF-P5, for the adsorption and removal of organic pollutants (short-chain alkyl derivatives 1-3 and pesticide molecules 4-6) from water with high removal efficiency (RE). However, PAF-P5 was incapable of adsorbing aromatic organic dyes 7-9. Adsorption kinetic studies indicated that the adsorption is mainly driven by strong host-guest interactions between 1-3 and the pillar[5]arene units in PAF-P5, while 4-6 only weakly interacted with the pillar[5]arene units in PAF-P5. Moreover, chemically breaking down the pillar[5]arene rings in PAF-P5 caused changes in the pore size, the microenvironment inside of the pores, and the frame morphology, and the resultant frameworks, PAF-DeP5, exhibited poor adsorption toward 1-6 but adsorbed 7-9 possibly through physical adsorption as implied by fitting the experimental data into the adsorption kinetic models.

Thiazolo[5,4-d]thiazole-Based Donor-Acceptor Covalent Organic Framework for Sunlight-Driven Hydrogen Evolution.

2D covalent organic frameworks (COFs) could have well-defined arrangements of photo- and electro-active units that serve as electron or hole transport channels for solar energy harvesting and conversion, but their insufficient charge transfer and rapid charge recombination impede the sunlight-driven photocatalytic performance. We report a new donor-acceptor (D-A) system, PyTz-COF that was constructed from the electron-rich pyrene (Py) and electron-deficient thiazolo[5,4-d]thiazole (Tz). With its bicontinuous heterojunction, PyTz-COF demonstrated exceptional optoelectronic properties, photocatalytic ability in superoxide anion radical-mediated coupling of (arylmethyl)amines and photoelectrochemical activity in sunlight-driven hydrogen evolution. Remarkably, PyTz-COF exhibited a photocurrent up to 100 µA cm-2 at 0.2 V vs. RHE and could reach a hydrogen evolution rate of 2072.4 µmol g-1 h-1 . This work is paving the way for reticular design of highly efficient and highly active D-A systems for solar energy harvesting and conversion.

A Triazine-Based Analogue of Graphyne: Scalable Synthesis and Applications in Photocatalytic Dye Degradation and Bacterial Inactivation.

Graphyne, a theorized carbon allotrope possessing only sp- and sp2 -hybridized carbon atoms, holds great potentials in many fields, especially in catalysis and energy-transfer/storage devices. Using a bottom-up strategy, we synthesized a new N-doped graphyne analogue, triazine- and 1,4-diethynylbenzene-based graphyne TA-BGY, in solution in gram-scale. The unique sp/sp2 carbon-conjugated TA-BGY possesses an extended porous network structure with a BET surface area of approximately 300 m2 g-1 . Owing to its low optical band gap (1.44 eV), TA-BGY was expected to have many applications, which were exemplified by the photodegradation of methyl orange and photocatalytic bacterial inactivation.

Unidirectional complexation of pillar[4]arene[1]benzoquinoneoxime with alkyl alcohols.

Despite progress in the unidirectional complexation of cyclodextrins and calixarenes with nonsymmetric guests, unidirectional complexation using pillararenes as hosts remains scarcely explored. In this report, we describe the formation of unidirectional [2]pseudorotaxane-like complexes which were realized using n-alkyl alcohol guests and pillar[4]arene[1]benzoquinoneoxime made from pillar[4]arene[1]quinone in a selective monofunctionalizing manner.

Systematic rim cyano-functionalization of pillar[5]arene and corresponding host-guest property varieties.

Synthetic investigation of the systematic replacement of alkoxy groups in pillar[5]arene by cyano ones was carried out. 2nCN-pillar[5]arenes (n = 1, 2, 3, 4 or 5) bearing different numbers of cyano functions on their rims were successfully prepared for the first time. Single-crystal X-ray diffraction studies showed that the nCN-pillar[5]arenes had unique conformations in the solid states. Besides, host-guest property studies of those nCN-pillar[5]arenes and 1,4-dicyanobutane showed the functionization number-related host-guest interaction varieties.

A Diaminopillar[5]arene-Based Macrobicyclic Molecule: Synthesis, Characterization and A Lock-Key Story.

A new macrobicyclic molecule (BC-DAP5), consisting of a diaminopillar[5]arene cavity and a fused ring, was successfully constructed using a Grubbs metathesis reaction. Further studies indicated that BC-DAP5 possessed a unique molecular behavior, showing a response to acid/base stimuli. In BC-DAP5, protons (acid) acted as a lock, locking the fused ring out of the cavity (pillar[5]arene), and a base served as the key, making the fused ring switch in or out freely. Reversible control of the molecular behavior was achieved simply by adding acid and base alternately.

Direct synthesis of covalent triazine-based frameworks (CTFs) through aromatic nucleophilic substitution reactions.

Despite extensive efforts, only three main strategies have been developed to synthesize covalent triazine-based frameworks (CTFs) thus far. We report herein a totally new synthetic strategy which allows C-C bonds in the CTFs to be formed through aromatic nucleophilic substitution reactions. The as-synthesized CTF-1 and CTF-2 exhibited photocatalytic water splitting activity comparable to the CTFs made using ionothermal or Brønsted acid-catalyzed polymerization. Interestingly, CTF-2 distinguished itself by its two-photon fluorescence (emission at ∼530 nm under irradiation at either 400 nm or 800 nm).

Engineering a pillar[5]arene-based supramolecular organic framework by a co-crystallization method.

A supramolecular organic framework, P5-bpy-SOF, made of perhydroxyl-pillar[5]arene (P5) and 4,4-bipyridine (bpy) and prepared by using a co-crystallization approach, showed a different hydrogen bonding pattern and a 3D molecular arrangement from that in the perhydroxyl-pillar[5]arene-based supramolecular organic framework (P5-SOF). TGA analyses, powder X-ray diffraction and gas absorption study confirmed P5-bpy-SOF's structural stability, permanent porosity, and, especially, selectivity of absorption of CO2 over N2.

Correction: Guest-regulated chirality switching of planar chiral pseudo[1]catenanes.

Correction for 'Guest-regulated chirality switching of planar chiral pseudo[1]catenanes' by Ya-Fen Yang et al., Org. Biomol. Chem., 2018, DOI: 10.1039/c8ob00156a.

Guest-regulated chirality switching of planar chiral pseudo[1]catenanes.

pseudo[1]Catenane 3 is in a self-included conformation in chloroform, but in dichloromethane, it exists in an equilibrium between the self-included conformational state and a de-threading one. The planar chirality inversion of 3 can be triggered by the host-guest complexation of 3 with adiponitrile G, but the extent of such chiral switching depends on the length of self-included bis(pyrazin-2-yloxy)alkane chains in 3 - longer chains are more favored than shorter ones in the inversion.

Multicavity macrocyclic hosts.

Multicavity macrocyclic hosts are host molecules comprising more than one macrocyclic guest binding components connected through multipoint linkages. Macrocycles, such as crown ethers, pillar[n]arenes, calix[n]arenes, and calix[4]pyrroles, have been used to fabricate multicavity hosts, either homotopic or heterotopic. This review is mainly focused on the molecular structures and host-guest behaviors of multicavity macrocyclic host molecules and their applications in the assembly of sophisticated supramolecular architectures.

A1/A2-Diamino-Substituted Pillar[5]arene-Based Acid-Base-Responsive Host-Guest System.

An acid-base-responsive supramolecular host-guest system based on a planarly chiral A1/A2-diamino-substituted pillar[5]arene (1)/imidazolium ion recognition motif was created. The pillar[4]arene[1]diaminobenzene 1 can bring an electron-deficient imidazolium cation into its cylindrically shaped cavity under neutral or basic conditions and release it under acidic conditions.