To achieve rapid intraparticle diffusion when metal-organic frameworks are used as adsorbents and/or catalysts, it is preferable to reduce their crystal size and improve their monodispersity. The simplest method for reducing the crystal size in a synthetic aqueous solution is increasing the ligand concentration. However, this produces an environmental load, because a large amount of ligand remains in the waste solution. In this study, size-controlled synthesis of the zeolitic imidazolate framework 67 (ZIF-67) was achieved by using a fine liquid droplet as the reaction field. This droplet was generated by electrospraying in the liquid phase, which improved the crystal size, morphology, and monodispersity of ZIF-67.

The core-shell Ni(OH)₂@Mg(OH)₂ (NM) hybrids were synthesized via precipitation of Ni(OH)₂ on the surface of Mg(OH)₂ (MH) nanoplates at room temperature. It was demonstrated that PP/NM displayed outstanding smoke suppression in comparison with PP/MH owing to the catalytic charring of PP/NM for generating vast multiwalled carbon nanotubes (MWCNTs), which facilitated the formation of compact char layers. Based on this study, the novel NM hybrids as catalytic flame retardants possessed the potential to eliminate the smoke hazard of the polyolefins system.

A bowl-shaped, bicyclic diol compound was synthesized by intramolecular twofold aldol condensation reaction of a decane-2,4,7,9-tetraone derivative. Two hydroxy groups at the concave side of the bicyclic compound provided convergent reaction sites for silylation. Reaction with tetrachlorosilane furnished two spirosilicate-type dimers that were remarkably stable toward hydrolysis as compared to other tetraalkoxysilanes.

Esterification reaction between phosphoric acid and methanol proceeded markedly at 6 GPa and 25 °C. The yields of monomethyl phosphate and dimethyl phosphate were 17.0% and 0.3%, respectively. The yield of monomethyl phosphate at 6 GPa was at least 34 times higher than that under ambient conditions. The esterification reaction was accompanied by crystallization of ice VII, a high-pressure form of ice. It is likely that the formation of ice VII was the driving force of the esterification reaction.

Our present work demonstrated electrochemical oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) activities of ultrathin nickel cobalt hydroxide (Ni_xCo_y-OH, Ni/Co = x/y) nanosheet films. A Ni₁Co₄-OH nanosheet film showed the lowest overpotential of all Ni/Co ratios. When the layer number of Ni₁Co₄-OH nanosheet film was changed, the larger layer number gave the lower overpotential. However, the 1–4 layers of nanosheet showed larger decreases of the overpotentials per layer (−61 mV/layer) than the 4–12 layers (−9 mV/layer).

As a homoditopic back-to-back host molecule, a cyclic 1,8-pyrenylene tetramer CP4 having two cavities for guest complexation was investigated. The unique two-face structural feature of CP4 allows it to bind spherical pristine fullerenes. The host-guest interactions were characterized by ¹H NMR spectroscopy and single-crystal X-ray diffraction analysis.

This paper describes the bolaamphiphilic properties of naturally occurring quercetin glycosides such as quercetin (Que), isoquercitrin (IQ), and quercetin polyglycoside (QP). The effects of sugar chain length on the micellization behaviors are discussed through the time-course of UV-vis spectra, the profiles of dynamic light scattering analyses, and the morphology of the micelles. It is indicated that the polysaccharide chains integrated on the surface of micelle would serve as a steric protecting group to afford kinetically stable micelles.

A catalytic transesterification reaction on phenolic hydroxyl groups by a carboxylate-type ionic liquid, 1-ethyl-3-methylimidazolium p-anisate ([Emim][OAn]), was investigated using a model reaction with phenol and vinyl propionate. Undesirable contamination of the ester group formed on the phenol with an acyl group derived from the acyl anion in the [Emim][OAn] was effectively suppressed. This catalytic reaction was applied to Kraft lignin, and the desired esterification was successfully promoted on the hydroxyl groups with a conversion of up to 94 mol %.

Novel homoleptic arylborane–dipyrrinatoplatinum(II) complex [Pt(B-ph-dipy)₂] (B-ph-dipy = 5-{4-(dimesitylboryl)phenyl}dipyrrinate) was designed and synthesized. Two stereoisomers of [Pt(B-ph-dipy)₂] based on the coordination geometry (i.e., square-planar (1) and distorted tetrahedral (1′)) were obtained and characterized. The complexes 1 and 1′ showed more intense absorption than a reference complex without any arylborane substituents [Pt(ph-dipy)₂] (2) (ph-dipy = 5-phenyldipyrrinate) in the >300 nm region. Furthermore, the emission spectrum of 1′ was broad and structureless compared to the structured emission spectra of 1 and 2. The emitting excited state of 1′ is ascribed to a mixed charge transfer of MLCT in the distorted tetrahedral bis(dipyrrinato)platinum(II) moiety and π(aryl)–p(B) CT in the arylborane moieties.

Speciation of rare earth elements (REE) in marine ferromanganese oxides (MFMO) was conducted by extended X-ray absorption fine structure (EXAFS) and sequential extraction to compare the enrichment mechanisms and extraction rates between MFMO and ion-adsorption type deposits, which can be reasonably explained by the formation of inner- and outer-sphere complexes in the two materials for yttrium and other REE.

Mechanically interlocked host frameworks are expected to show dynamic guest inclusion/release without disruption of their inherent structures. Here, we synthesized a double-walled knotted cage from a kinetically inert Pt(II) block, which has a robust but semiflexible backbone to give an expansible cavity with expansible portals. The Pt cage showed great kinetic stability toward base, acid, and nucleophiles. Comparisons of the kinetics with a Pd(II) analog strongly supported the portal expansion mechanism for the guest inclusion in the double-walled cages.

Four standard electrode potentials versus the standard hydrogen electrode (SHE) are reported in a polar aprotic solvent, N,N-dimethylacetamide (DMA) at 298 K: (1) −0.319 ± 0.033 V for a H₂ production; (2) −0.415 ± 0.033 V and −1.195 ± 0.033 V for CO₂ reductions to produce carbon monoxide (CO) in the absence and presence of water, respectively; and (3) +0.918 ± 0.033 V for an O₂ reduction (ORR) or O₂ evolution (OER) reactions. These potentials were estimated based on measurements of absolute (and conventional) acidity constants for several Brønsted acids in DMA including CO₂ with water ([H₂O] = 1.1 M) of which absolute pK_a is 18.6 ± 0.2 in reference to aqueous proton at standard states. The standard Gibbs transfer energy of proton was calculated to be −31 ± 3 kJ/mol from water to DMA at 298 K.

We report here a novel strategy for the synthesis of 1,2,3,4,9-pentaarylcarbazole. In this method, an N-alkynylation of sulfonamide facilitated by an iodonium salt, and spontaneous cycloaddition of the resulting ynamide were crucial for the rapid construction of the central carbazole core.

A unique strategy for the fabrication of room temperature phosphorescent guest/host crystals, which consist of π-extended cyclized guests and their mother uncyclized flexible brominated hosts, is reported. Combinations of bisbenzofuropyrazines/bis(2-bromophenoxy)pyrazines are the examples. Judicious choice of the guest/host pair allows to create highly phosphorescent crystals.

1-Phenylbiguanide in the solid state was oxidized by iodine, and a π-cation radical was observed as a charge-transfer complex. The dark-brown powder exhibited a charge-transfer band in the near-UV region. The electron spin resonance (ESR) spectra of the complex exhibited Lorentzian peaks with g = 2.007–2.008, which suggested an imino-centered, monocation radical. Regardless of the imino fragment with a σ lone-pair, the cationic species was characterized as a π-radical conjugated with the phenyl group. This is the first observation of π-cation radical complexes of guanidine derivatives in the solid state.

Biopolyimides poly(ATA-CBDA) made from of 4,4′-diamino-α-truxillic acid dimethyl ester (ATA) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) were synthesized and its electric volume resistivity measured at various electric voltages at 10–60 °C. The volume resistivity for Kapton and biopolyimide films showed a sudden decrease at a critical electric field of 2.6 × 10⁷ and 1.0 × 10⁷ V/m, respectively. The activation energy at low electric field for Kapton and biopolyimide was 68 and 90 kJ/mol, respectively, meanwhile at high electric field for Kapton and biopolyimide was 45 and 74 kJ/mol, respectively. These results indicate that the carriers for electric conduction for biopolyimide weakly interact with the polymer chain and the biopolyimide contains many conductive carriers than Kapton.

A new series of donor-donor′-acceptor molecules (D-D′-A design) is introduced. Due to different molecular configurations of the emitters, multiple triplet states were detected and happen to drive one thermally activated delayed fluorescence (TADF) with very short lifetime of the order of nanoseconds. A longer TADF component of microsecond order was also observed, thus showing an interesting case of dual upconversion. These results reveal how TADF becomes efficient enough to overwhelm the prompt fluorescence with the assistance of vibrational and rotational motions.

The effects of push-pull porphyrin dyes as well as copper(I/II) redox shuttles on photovoltaic properties have been examined toward high-performance dye-sensitized solar cells (DSSCs). DSSC with a combination of porphyrin dye LG4 and bis(4,4′,6,6′-tetramethyl-2,2′-bipyridyl)copper(I/II) exhibited the highest power conversion efficiency of 5.07% ever reported for porphyrin-based DSSCs using copper(I/II) redox shuttles.

An efficient synthesis of chiral syn-α,γ-dihydroxycarbonyl units from readily available achiral precursors in three pots under mild conditions was developed. This method explored the asymmetric direct cross-aldol reaction of two different aldehydes in the presence of an organocatalyst to generate a chiral β-hydroxyaldehyde, which was converted into a 4-nitromethyl-1,3-dioxane derivative as a diastereo-mixture via a sequence of nitroalkane addition and acetalization. The 4-nitromethyl-1,3-dioxane derivative was then transformed either to a carboxylic ester or to an aldehyde/ketone. The chiral syn-α,γ-dialkoxy esters and aldehydes/ketones were all obtained with excellent enantiopurity and diastereoselectivity after a base-promoted epimerization.

Lead halide perovskite has emerged as a promising photovoltaic material due to its excellent power conversion efficiency (PCE). However, the toxicity problem of lead-based perovskite hampers the commercialization of perovskite solar cells. Here, we develop several Sb(V) complexes with pyridyl cations and serve as absorber layer for lead-free perovskite solar cells. The designed complexes were based on 4-tert-butylpyridine (tBP) and N-ethylpyridinium (N-EtPy) cations with bandgaps of 2.01 eV and 1.95 eV, which showed their potential for solar cells and optoelectronic applications. We also found a chemical rule for stable Sb complexes in terms of the bond connectivity of pnictogen-antimony. Initial studies produce a solar cell with a PCE of 0.9% and offer inspiration for further exploration of environment-friendly perovskite families.

Two novel A-D-A shaped dimesitylboron endcapped S,N-heteroacenes (DMB-DTP and DMB-BTTP) were designed and synthesized. With the extension of conjugation from DMB-DTP to DMB-BTTP, a serious of changes in optical and electrochemical properties could be detected. Notably, compared with DMB-DTP, the fluorescence quantum yield of DMB-BTTP was prominently enhanced to 95%. UV-vis absorption and fluorescence titration experiments were also carried out, which confirmed both the target compounds exhibited “turn-on” fluoride-binding properties with high sensitivities.

We characterized the adsorption morphologies of polyethylene glycol (PEG) and cationic surfactants on gold in H₂SO₄ aqueous solutions in the presence and absence of Cl⁻ ions. The addition of Cl⁻ ions resulted in the formation of globular aggregates on a smooth adsorption film for PEG, whereas in the formation of wormlike adsorption aggregates for hexadecyltrimethylammonium bromide.

An ordered Fe-Mn-Ce/TiO₂ catalytic membrane was obtained via template assisted sol-gel route. Comparing with the templates of P123 and L64, the catalyst with template F123 delivered a highly ordered pore structure and large surface area, thus exhibiting high SCR activity in the temperature range 225–375 °C. After coating the catalyst on the support layer three times, the catalytic membrane presented high SCR activity, mostly similar to catalyst powder.

Hetero[8]circulenes have emerged as novel heteroatom-doped polycyclic aromatic hydrocarbons whose properties depend on the constituent aromatic units. Herein we report a C-doped variant, diazadimethano[8]circulene 3, in which two diphenylcyclopentadiene units are installed into the core of [8]circulene that may prevent effective conjugation. The structure of 3 has been revealed to have two longer C–C bonds in the central eight-membered ring, while the absorption and emission profiles are quite similar to those of tetraaza[8]circulene. Stable radical cation 3⁺ was easily obtained by facile oxidation of 3. X-ray diffraction analysis of 3⁺ showed a slipped dimer arrangement with negligible intermolecular interaction. Interestingly, the lowest-energy absorption of 3⁺ reaches around 2500 nm, while that of 3 is 447 nm.

The total synthesis of polycyclic natural products is often characterized by methods for constructing fused ring systems, in which there are many examples such as stepwise synthesis, cascade cyclization, rearrangement of spirocycles, and so on. In this highlight review, we focus on the total synthesis of epilupinine as the simplest natural product with a fused ring system. Due to the simple fused ring system, total synthesis of epilupinine has been attempted by various different approaches, and various methods for constructing the octahydro-2H-quinolizine (quinolizidine) skeleton have been developed.

Bibenzyls are one of the most essential natural ingredients for genus Bulbophyllum owing to various biological activities. Two bibenzyls (batatasin III and cirrhopetalidin) were first separated and elucidated from the stems of Bulbophyllum taeniophyllum, as well as used as standards for HPLC determination. Furthermore, the developed method was validated by performing with linearity, LODs, LOQs, precision, stability, repeatability and recovery. Then a simple and reliable HPLC-VWD method was adopted for simultaneous separation and quantitation of both analytes. In addition, the DPPH assay demonstrated that only cirrhopetalidin showed potent DPPH free radicalscavenging activity.

The phase separation of an aqueous ionic liquid in migration by electrophoresis was utilized for online sample enrichment in microchip electrophoresis. The enrichment of rhodamine 6G in a sample solution was examined to validate the present concept. The peaks of the dye in the electropherograms became sharper and more intense after phase separation in migrating than without phase separation. Optimizing the operating conditions should enable highly target-selective sample enrichment with a higher enrichment factor under microflows.

We show that oxyhalide Bi₅PbTi₃O₁₄Cl is a potential photocatalyst for visible-light-induced water splitting owing to the appropriate band levels for both water reduction and oxidation. The present oxyhalide, the first example of an active material with a triple-layered Sillén–Aurivillius perovskite structure, is found to possess a more negative valence band maximum and a smaller bandgap than those of analogous oxide Bi₄Ti₃O₁₂, because of stronger hybridization between Bi/Pb-6s and O-2p orbitals.

CaCO₃ is used by many invertebrates for biomineralization. Organic materials in biominerals stabilize amorphous CaCO₃ (ACC). Investigation of biomineral formation requires analysis of ACC. X-ray absorption near edge structure (XANES) analysis was used to examine the chemical form of Ca in ACC solutions. The Ca K-edge XANES spectra showed that Ca in a solution containing phosphate and magnesium ions existed as a form of ACC. Ca K-edge XANES analysis can be useful to identify ACC in solution under atmospheric conditions.

Graphene/Mn₃O₄ composites were synthesized by a facile flash irradiation method at room temperature. The flash irradiating triggers the deoxygenation reaction of graphene oxide and the decomposition reaction of manganese nitrate. Additionally, the graphene/Mn₃O₄ positive electrodes showed a wide operating potential of 0–1.2 V (vs SCE) in aqueous electrolyte for supercapacitors. The extended potential windows further expand the stable cell voltage (2.2 V) for aqueous asymmetric supercapacitors with a high energy density of 18.5 Wh kg⁻¹ at power density of 0.28 kW kg⁻¹.

A novel and effective analytical method was developed for the determination of trace cobalt by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) after simultaneous dispersive liquid-liquid microextraction (S-DLLME) based on contemporaneous complexation and extraction. Approximately 48 times enhancement in detection power was recorded based on the comparison of detection limits of the developed system (4.7 ng/mL) with the detection power of the conventional FAAS. Percent relative standard deviation for the lowest concentration was calculated as 3.8%. Spiked recovery experiments on chamomile tea extract samples were carried out to determine applicability of the developed method to real sample matrix. Percent recovery results for two different concentrations were approximately 100%, with standard deviation values below 10%.