Prominent Intrinsic Proton Conduction in Two Robust Zr/Hf Metal-Organic Frameworks Assembled by Bithiophene Dicarboxylate.

To date, developing crystalline proton-conductive metal-organic frameworks (MOFs) with an inherent excellent proton-conducting ability and structural stability has been a critical priority in addressing the technologies required for sustainable development and energy storage. Bearing this in mind, a multifunctional organic ligand, 3,4-dimethylthiophene[2,3-]thiophene-2,5-dicarboxylic acid (HDTD), was employed to generate two exceptionally stable three-dimensional porous Zr/Hf MOFs, [ZrO(OH)(DTD)]·5DMF·HO () and [HfO(OH)(DTD)]·4DMF·HO ), using solvothermal means. The presence of Zr or Hf nodes, strong Zr/Hf-O bonds, the electrical influence of the methyl group, and the steric effect of the thiophene unit all contribute to their structural stability throughout a wide pH range as well as in water.

Tailored Porous Ferrocene-Based Metal-Organic Frameworks as High-Performance Proton Conductors.

Although crystalline metal-organic frameworks (MOFs) have gained a great deal of interest in the field of proton conduction in recent years, the low stability and poor proton conductivity (σ) of some MOFs have hindered their future applications. As a result, resolving the issues listed above must be prioritized. Due to their exceptional structural stability, MOFs with ferrocene groups that exhibit particular physical and chemical properties have drawn a lot of attention.

Superprotonic conductivity of ketoenamine covalent-organic frameworks grafted by imidazole-based units.

The achievement of covalent organic frameworks (COFs) with high stability and exceptional proton conductivity is of tremendous practical importance and challenge. Given this, we hope to prepare the highly stable COFs carrying CN connectors and enhance their proton conductivity via a post-modification approach. Herein, one COF, TpTta, was successfully synthesized by employing 1,3,5-triformylphloroglucinol (Tp) and 4,4',4″-(1,3,5-triazine-2,4,6-triyl)-trianiline (Tta) as starting materials, which has a β-ketoenamine structure bearing a large amount of -NH groups and intramolecular H-bonds.

Four Lanthanide(III) Metal-Organic Frameworks Fabricated by Bithiophene Dicarboxylate for High Inherent Proton Conduction.

Currently, it is still a challenge to directly achieve highly stable metal-organic frameworks (MOFs) with superior proton conductivity solely through the exquisite design of ligands and the attentive selection of metal nodes. Inspired by this, we are intrigued by a multifunctional dicarboxylate ligand including dithiophene groups, 3,4-dimethylthieno[2,3-]thiophene-2,5-dicarboxylic acid (HDTD), and lanthanide ions with distinct coordination topologies. Successfully, four isostructural three-dimensional lanthanide(III)-based MOFs, [Ln(DTD)(DEF)]·DEF·6HO [Ln = Tb (), Eu (), Sm (), and Dy ()], were solvothermally prepared, in which the effective proton transport will be provided by the coordinated or free solvent molecules, the crystalline water molecules, and the framework components, as well as a large number of highly electronegative S and O atoms.

Direct Growth of van der Waals Tin Diiodide Monolayers.

Two-dimensional (2D) van der Waals (vdW) materials have garnered considerable attention for their unique properties and potentials in a wide range of fields, which include nano-electronics/optoelectronics, solar energy, and catalysis. Meanwhile, challenges in the approaches toward achieving high-performance devices still inspire the search for new 2D vdW materials with precious properties. In this study, via molecular beam epitaxy, for the first time, the vdW SnI monolayer is successfully fabricated with a new structure.

Kinetics-Limited Two-Step Growth of van der Waals Puckered Honeycomb Sb Monolayer.

Puckered honeycomb Sb monolayer, the structural analog of black phosphorene, has been recently successfully grown by means of molecular beam epitaxy. However, little is known to date about the growth mechanism for such a puckered honeycomb monolayer. In this study, by using scanning tunneling microscopy in combination with first-principles density functional theory calculations, we unveil that the puckered honeycomb Sb monolayer takes a kinetics-limited two-step growth mode.

Tuning the Electronic Structure of an α-Antimonene Monolayer through Interface Engineering.

The interfacial charge transfer from the substrate may influence the electronic structure of the epitaxial van der Waals (vdW) monolayers and, thus, their further technological applications. For instance, the freestanding Sb monolayer in the puckered honeycomb phase (α-antimonene), the structural analogue of black phosphorene, was predicted to be a semiconductor, but the epitaxial one behaves as a gapless semimetal when grown on the -WTe substrate. Here, we demonstrate that interface engineering can be applied to tune the interfacial charge transfer and, thus, the electron band of the epitaxial monolayer.

Luminescent triphenylamine-based metal-organic frameworks: recent advances in nitroaromatics detection.

Luminescent metal-organic frameworks (LMOFs), as one branch of MOFs, have attracted considerable attention in recent years due to their good crystallinity, structural diversity, tunable porosity and easily induced fluorescence emission. Importantly, their photoluminescence (PL) properties can be adjusted by altering metal ions or metal clusters and organic ligands in one hybrid system. Among the various sensing applications, using LMOFs as chemical sensors to detect the explosive and environment pollution causing nitroaromatic compounds (NACs) is an important topic.

A new Zn metallocryptand with unprecedented diflexure helix induced by V-shaped diimidazole building blocks.

Taking advantage of V-shaped ligands, a Zn metallocryptand, namely {[Zn(didp)(m-bdc)]}, (1) [didp = 2,8-di(1H-imidazol-1-yl)-dibenzothiophene and m-Hbdc = isophthalic acid], has been hydrothermally synthesized. Single-crystal X-ray diffraction analysis reveals a 26-membered butterfly-type metallomacrocycle [Zn(didp)]. One m-bdc ligand bridges [Zn(didp)] units to form a laterally non-symmetric [Zn(didp)(m-bdc)] metallocryptand with an exo-exo conformation.

A Comparative Study of Proton Conduction Between a 2D Zinc(II) MOF and Its Corresponding Organic Ligand.

Until now, comparative studies on proton conductivity between organic ligands and related metal-organic frameworks (MOFs) have been very limited. Herein, a stable 2D Zn(II) MOF, [Zn(L)Cl] (), has been successfully synthesized by using a zwitterionic-type organic ligand, 2-(1-(carboxymethyl)-1-benzo[d]imidazol-3-ium-3-yl)acetate (HL). It is found that there are a large amount of free carboxyl groups and hydrogen bonds in the solid-state structure of HL, and a large number of chlorine ions are aligned in the channels of , which is favorable to the efficient proton transfer.

Quasiparticle interference evidence of the topological Fermi arc states in chiral fermionic semimetal CoSi.

Chiral fermions in solid state feature "Fermi arc" states, connecting the surface projections of the bulk chiral nodes. The surface Fermi arc is a signature of nontrivial bulk topology. Unconventional chiral fermions with an extensive Fermi arc traversing the whole Brillouin zone have been theoretically proposed in CoSi.

Neoadjuvant therapy and sentinel lymph node biopsy in HER2-positive breast cancer patients: results from the PEONY trial.

Objective: The aim of the study is to evaluate the optimal timing of sentinel lymph node biopsy (SLNB) in patients with clinical negative axillary lymph nodes (ALNs) before neoadjuvant therapy (NAT) and the feasibility of SLNB substituting for ALN dissection in patients with positive ALNs who convert to node negative, for HER2-positive disease.

Methods: Patients receiving SLNB with dual tracer mapping in the PEONY trial were analyzed.

Results: For 80 patients with clinical negative ALNs, the node negative rate by pathology after NAT was 83.

One-pot concomitant preparation of two copper(II) coordination polymers with different configurations of bridging bithiophene ligands.

By employing the conjugated bithiophene ligand 5,5'-bis(1H-imidazol-1-yl)-2,2'-bithiophene (bibp), which can exhibit trans and cis conformations, two different Cu coordination polymers, namely, poly[[μ-5,5'-bis(1H-imidazol-1-yl)-2,2'-bithiophene-κN:N'](μ-4,4'-oxydibenzoato-κO:O')copper(II)], [Cu(CHO)(CHNS)] or [Cu(bibp)(oba)], (I), and catena-poly[μ-aqua-bis[μ-5,5'-bis(1H-imidazol-1-yl)-2,2'-bithiophene-κN:N']bis(μ-4,4'-oxydibenzoato)-κO:O':O'';κO:O',O'':O'-dicopper(II)], [Cu(CHO)(CHNS)(HO)] or [Cu(bibp)(oba)(HO)], (II), have been prepared through one-pot concomitant crystallization and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analysis. Single-crystal X-ray diffraction indicates that the most interesting aspect of the structure is the existence of sole trans and cis conformations of the bibp ligand in a single net of (I) and (II), respectively. Compound (I) displays a threefold interpenetrating three-dimensional framework with a 4-connected {6.

Two Highly Stable Proton Conductive Cobalt(II)-Organic Frameworks as Impedance Sensors for Formic Acid.

Metal-organic frameworks (MOFs) have been extensively explored as advanced chemical sensors in recent years. However, there are few studies on MOFs as acidic gas sensors, especially proton conductive MOFs. In this work, two new proton-conducting 3D MOFs, {[Co (p-CPhHIDC) (4,4'-bipy)(H O)]⋅2 H O} (1) (p-CPhH IDC=2-(4-carboxylphenyl)-1 H-imidazole-4,5-dicarboxylic acid; 4,4'-bipy=4,4'-bipyridine) and {[Co (p-CPhHIDC) (bpe)(H O)]⋅3 H O} (2) (bpe=trans-1,2-bis(4-pyridyl)ethylene) have been solvothermally prepared and investigated their formic acid sensing properties.

Spectrum-effect relationship between HPLC fingerprints and bioactive components of on increasing the peak bone mass of rat.

The traditional Chinese medicine of plays an important role in invigorating gas for ascending, benefiting blood for promoting production of fluid, and promoting circulation for removing obstruction in collaterals, which is consistent with the principle of treatment for osteoporosis. This study is designed to investigate the bioactive components on increasing peak bone mass (PBM) by exploring the spectrum-effect relationship between chromatography fingerprints and effect. Multiple indicators are selected to evaluate the pharmacological activity.

Van der Waals Heteroepitaxial Growth of Monolayer Sb in a Puckered Honeycomb Structure.

Atomically thin 2D crystals have gained tremendous attention owing to their potential impact on future electronics technologies, as well as the exotic phenomena emerging in these materials. Monolayers of α-phase Sb (α-antimonene), which shares the same puckered structure as black phosphorous, are predicted to be stable with precious properties. However, the experimental realization still remains challenging.

Observation of Coulomb gap in the quantum spin Hall candidate single-layer 1T'-WTe.

The two-dimensional topological insulators host a full gap in the bulk band, induced by spin-orbit coupling (SOC) effect, together with the topologically protected gapless edge states. However, it is usually challenging to suppress the bulk conductance and thus to realize the quantum spin Hall (QSH) effect. In this study, we find a mechanism to effectively suppress the bulk conductance.

A triphenylamine-functionalized luminescent sensor for efficient p-nitroaniline detection.

The combination of π-conjugated fluorophores within a hybrid system gives rise to a triphenylamine-functionalized material [Zn(bpba)(NO3)] (1) (Hbpba = 4-(bis(4-(pyridin-4-yl)phenyl)amino)benzoic acid). Compound 1 features a 2D + 2D → 2D parallel polycatenation structure with 63-hcb net. Photophysical studies revealed that the title phase showed superior sensitivity towards p-nitroaniline (p-NA) with a low detection limit (down to ∼0.

A new Cd coordination polymer with a self-penetrating architecture induced by the molecular conformation of a rigid bithiophene ligand.

The design and synthesis of coordination polymers with a self-penetrating architecture has attracted much interest not only due to their interesting structures but also due to their potential applications. 5,5'-Bis(pyridin-4-yl)-2,2'-bithiophene (bpbp), as a conjugated bithiophene ligand, can exhibit trans and cis conformations and this can lead to the construction of a self-penetrating architecture. In addition, the semi-rigid ancillary ligand 4,4'-oxybis(benzoic acid) (Hoba) can adopt different coordination modes, resulting in coordination polymers with high-dimensional skeletons.

pH-Controlled assembly of two novel Dawson-sandwiched clusters involving the in situ reorganization of trivacant α-[P2W15O56](12-) into divacant α-[P2W16O57](8.).

Modified classical trivacant Wells-Dawson α-[P2W15O56](12-) and the assembly of related sandwiched transition metal clusters are of interest, but surprisingly few reports of these materials exist because of the sensitivity of α-[P2W15O56](12-) to the assembly environment. Herein, we describe the pH-controlled assembly of two novel Dawson-sandwiched clusters, (H2bpz)6[Co2(P2W16O57)2]·22H2O (1, bpz = 3,3',5,5'-tetramethyl-4,4'-bipyrazole) and (H2bpz)6[Co3H2(P2W16O57)(P2W15O56)(H2O)]·12H2O (2), involving the in situ transformation of α-[P2W15O56](12-). Both clusters were characterized by X-ray single-crystal diffraction, FT-IR spectroscopy, UV-Visible spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and elemental analyses.

Two luminescent Zn(II) metal-organic frameworks for exceptionally selective detection of picric acid explosives.

Two luminescent Zn(II) metal-organic frameworks were prepared from a π-conjugated thiophene-containing carboxylic acid ligand. These two MOFs show strong luminescene and their luminescence could be quenched by a series of nitroaromatic explosives. Importantly, they exhibit very highly sensitive and selective detection of picric acid compared to other nitroaromatic explosives.

Chiral crystallization and optical properties of three metal complexes based on two non-centrosymmetric tripodal ligands.

Chiral coordination polymers have attracted much attention due to their special properties and significant applications. In this work, we synthesized two non-centrosymmetric ligands, N,N-bis(4-(1H-imidazol-1-yl)phenyl)-4-(pyridin-4-yl)aniline (DIMPPA) and N-(4-(1H-imidazol-1-yl)phenyl)-4-(pyridin-4-yl)-N-(4-(pyridin-4-yl)phenyl)aniline (MIDPPA), via structural modification of two reported centrosymmetric ligands; after that achiral → chiral induction occurred in the construction of three coordination polymers namely {[Cd(DIMPPA)(5-OH-bdc)](H2O)}n (1), {[Co(DIMPPA)(5-OH-bdc)](H2O)}n (2) and {[Cd2(MIDPPA)2(D-ca)2(H2O)2](H2O)5}n (3), when replacing the reported centrosymmetric ligands with non-centrosymmetric ligands (5-OH-H2bdc = 5-hydroxyisophthalic acid, D-H2ca = D-camphoric acid). Isostructural complexes 1 and 2 exhibit chiral 2D → 3D frameworks with the coexistence of polyrotaxane and parallel polycatenation features.

Syntheses, crystal structures, and optical properties of five metal complexes constructed from a V-shaped thiophene-containing ligand and different dicarboxylate ligands.

Five new metal complexes, {[Ni(DIDP)(m-bdc)(H2O)]·5H2O}n (1), {[Zn(DIDP)(hfipbb)]·2DMA}n (2), {[Zn(DIDP)(4,4'-sdb)]·H2O}n (3), {[Co(DIDP)(p-bdc)]}n (4), and {[Co2(DIDP)(hfipbb)2]·H2O}n (5), have been synthesized by reactions of the corresponding metal ions with a V-shaped ligand 2,8-di(1H-imidazol-1-yl)dibenzothiophene (DIDP) and different aromatic dicarboxylic acids, namely isophthalic acid (m-H2bdc), terephthalic acid (p-H2bdc), 4,4'-(hexafluoroisopropylidene)bis(benzoic acid) (H2hfipbb), and 4,4'-sulfonyldicarboxylic acid (4,4'-H2sdb), respectively. The structures of the complexes were determined by X-ray single-crystal diffraction. Complex 1 is a 1D chain structure containing a one-dimensional channel along the a direction and is further extended via O-H···S hydrogen bonds and C-H···π stacking interactions into a 3D framework.