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Cobalt 5,15-diazaporphyrin as a novel molecular catalyst immobilized onto carbon nanotubes was developed for highly efficient electrocatalytic CO2 reduction to CO with a faradaic efficiency above 99% at −0.7 V and −0.8 V versus a reversible hydrogen electrode. Compared to cobalt phthalocyanine, the decrease in electronegative nitrogen atoms at the meso position effectively increases the electron density of the central metal, making it easier to react with Lewis acid CO2. [ABSTRACT FROM AUTHOR]

Specially shaped high-nuclear lanthanide cluster assembly has attracted widespread attention, but the study of their self-assembly mechanism is still stagnant. Herein, we used a polydentate chelating bis-acylhydrazone ligand to construct a rare 16-nuclear dysprosium cluster 1 with a brucite-like structure. The capture agents, pivalic acid and di(pyridin-2-yl)methanone, were added into the reaction system, and the hexanuclear dysprosium cluster 2 and heptanuclear dysprosium cluster 3 were obtained, respectively. Clusters 2 and 3 support the out-to-in growth mechanism as key evidence. To the best of our knowledge, this study is the first to use truncation reaction to decipher the formation mechanism of high-nuclear lanthanide clusters. [ABSTRACT FROM AUTHOR]

Building a hydrogen-bonded organic framework (HOF) that is resistant to strong acids and bases has always been challenging. Especially for lanthanide HOFs with large volume, irregular shape, and weak noncovalent force, their high stability is extremely difficult to achieve. Herein, we have used the reaction of 2-hydroxybenzaldehyde, 5-chloro-2-hydroxybenzaldehyde, 5-bromo-2-hydroxybenzaldehyde, 2-hydroxy-5-methylbenzaldehyde, and 5-fluoro-2-hydroxybenzaldehyde with 2,2-dimethylpropane-1,3-diamine and DyCl3·6H2O under room temperature conditions to obtain five Dy–HOFs [Dy(L1−R)(L2−R)]n (R = H (1), Cl (2), Br (3), CH3 (4), F (5)). Notably, the above Dy–HOFs are immersed in solutions with different pH values (1–13) for 20 days and maintain a high degree of stability. Moreover, the solid-state fluorescence of Dy–HOF samples immersed under acidic conditions has a "turn-on" response, and the solid-state fluorescence increases with increased acidity. This study is the first to investigate a series of highly stable metal–HOFs that is constructed by adjusting the substituents on the ligand, and the acid-responsive "turn-on" solid-state fluorescence of metal HOFs is reported for the first time. The anti-counterfeiting test results show that the ink made from the samples before and after the acid treatment can achieve dual anti-counterfeiting properties under sunlight and ultraviolet light. In addition, the ion sensing experiment also shows that the sample solution soaked in acid can specifically recognize Pb(II) ions. Magnetic research shows that all Dy–HOFs show obvious frequency-dependent behavior under zero field conditions, while 1, 4 and 5 show obvious single-molecule magnet behavior. [ABSTRACT FROM AUTHOR]

The versatility of multicolor imaging of human tissues based on staining with perylene monoimide–mannose conjugates PMI-Man and co-staining with PMI-Man and eosin (P&E) was investigated for human cancer and normal tissues. Staining with PMI-Man or co-staining with PMI-Man and eosin showed a perfect histological morphology both in confocal fluorescence microscopy and light microscopy. This approach provided a universal colorful staining method for cancer tissues and normal tissues. [ABSTRACT FROM AUTHOR]

A mannose-modified perylene monoimide derivative PMI-Man was developed, which shows highly selective binding to double-stranded DNA molecules, potent live/dead cell imaging, and histological imaging via both confocal and light microscopies. This approach can be used to develop a universal colorful staining method for human tissues for both confocal and light microscopies. [ABSTRACT FROM AUTHOR]

An efficient copper-catalyzed tandem regioselective cis-carbometallation/cyclization of imine-ynamides with arylboronic acids has been developed. This method leads to a facile and practical synthesis of valuable 2,3-disubstituted indolines in moderate to excellent yields and features a broad substrate scope and wide functional group tolerance. Other significant features of this protocol include the use of readily available starting materials, high flexibility, simple procedure and mild reaction conditions. [ABSTRACT FROM AUTHOR]

A new general de novo synthesis of pharmaceutically important α-aryl β-perfluoroalkyl ketones has been disclosed. Compared with trifluoromethylation-initiated radical 1,2-aryl migration of α,α-diaryl allylic alcohols, this protocol employs a new strategy of biomimetic carbene catalysis to assemble alkene, aldehyde and perfluoroalkyl reagents, providing access to products with excellent flexibility of the aryl unit and perfluoroalkyl group. This method also demonstrates excellent functional group compatibility, including some Grignard reagent sensitive groups. [ABSTRACT FROM AUTHOR]

We obtained a binuclear Gd(III) complex [Gd2(L1)2(NO3)4] (1, HL1 = (E)-2-(2-(pyridin-2-ylmethyleneamino)ethoxy)ethanol) by reacting N2O2-tetradentate chelating ligand HL1 with Gd(NO3)3·6H2O at solvothermal temperature of 100 °C. Time-dependent high-resolution electrospray ionization mass spectrometry (HRESI-MS) followed the formation of 1 and revealed it's the assembly mechanism: HL1 → Gd(L1) → Gd2(L1)2. When we used the NO2-tridentate chelating ligand HL2 (HL2 = 2-(2-aminoethoxy)ethanol) under the same reaction conditions, we obtained an "hourglass-like" nonanuclear Gd(III) cluster [Gd9(L2)8(μ3-OH)8(μ4-O)2(NO3)8]·2CH3OH·H2O (2). Their assembly mechanism was proposed: HL2 → Gd(L2) → Gd2(L2)2 → Gd3(L2)3 → Gd4(L2)4 → Gd5(L2)4 → Gd9(L2)8. Most notably, when we used the NO-bidentate chelate ligand HL3 (HL3 = picolinic acid), we obtained a dodecanuclear Gd(III) cluster [Gd12(L3)8(OH)16(NO3)8(OH)4(H2O)4]·22CH3OH·25CH3CN (3) under the same reaction conditions. We found that the formation process of cluster 3 involved two different and mutually interfering self-assembly processes, namely, multitemplate-induced assembly (HL3 → Gd(L3) → Gd2(L3)2 → Gd12(L3)8) and stepwise assembly (HL3 → Gd(L3) → Gd2(L3)2 → Gd3(L3)2 → Gd4(L3)2 → Gd5(L3)2 → Gd6(L3)2 → Gd12(L3)8). [ABSTRACT FROM AUTHOR]

The most effective way to understand reaction mechanisms and kinetics is to identify the reaction intermediates and determine the possible reaction patterns. The influencing factors that must be considered in the self-assembly of clusters are the type of ligand, metal ion, coordination anion and the pH of the solution. However, changes in ligand substituents resulting in different self-assembly processes to obtain different types of structures are still very rare, especially with –H and –CH3 substituents, which do not exert significant steric hindrance effects. In this study, planar mononuclear Ni(L1)2 (L1 = 2-ethoxy-6-(iminomethyl)phenol) was dissolved in methanol and combined with Dy(NO3)3·6H2O for 48 h at room temperature to obtain a butterfly-like Ni2Dy2 cluster ([Dy2Ni2(L1)4(CH3O)2(NO3)4], 1). The Dy(III) ions in cluster 1 are in an O8N coordination environment, and the Ni(II) ions are in an O5N coordination environment. High-resolution electrospray ionization mass spectrometry (HRESI-MS) was used to track species changes during the formation of cluster 1. Six key intermediate fragments were screened, and the self-assembly mechanism was proposed as Ni(L1)2 → HL1 + NiL1 → DyL1/Ni(L1)2′ → DyNi(L1)2 → Dy2Ni2(L1)4. Through this assembly mechanism, we found that Ni(L1)2 was first cleaved into HL1 + NiL1 and then further assembled to obtain 1. Another butterfly-like tetranuclear heterometallic cluster ([Dy2Ni2(L2)4(CH3O)2(NO3)4], 2) was obtained using planar mononuclear Ni(L2)2 (L2 = (E)-2-ethoxy-6-((methylimino)methyl)phenol) with –CH3 substitution on the nitrogen atom under the same reaction conditions. The structural analysis of cluster 2 showed that the Dy(III) ions are in an O9 coordination environment, and the Ni(II) ions are in an O4N2 coordination environment. HRESI-MS was used to trace species changes during the formation of 2, and the assembly mechanism was proposed as Ni(L2)2 → DyNi(L2)2 → Dy2Ni(L2)2 → Dy2Ni2(L2)4. Analysis of the assembly mechanism of 2 showed that Ni(L2)2 was twisted during the reaction, and its coordination point was exposed to capture the Dy(III) ions. Finally, Dy(NO3)3·6H2O was replaced with NaN3 to obtain a [Ni2Na2(L2)4(N3)4] cluster (3) under the same reaction conditions and verify the above-mentioned torsion step. HRESI-MS was also used to trace the assembly process, and the assembly mechanism was proposed as Ni(L2)2 → NiNa(L2)2 → NiNa2(L2)2 → Ni2Na2(L2)4. Herein, the effect of interference from substitution and the regulation self-assembly process were discovered in the formation of 3d–4f heterometallic clusters, and different types of coordination clusters were obtained. [ABSTRACT FROM AUTHOR]

A series of gold-catalysed intramolecular anti-Markovnikov hydroamination-initiated azidation, allylation and heteroarylation reactions of chiral homopropargyl sulfonamides have been developed. Various enantioenriched 2,5-disubstituted pyrrolidines are obtained in moderate to excellent yields with excellent enantioselectivities and generally high diastereoselectivities. [ABSTRACT FROM AUTHOR]

A single gold nanopore with high surface enhanced Raman spectroscopy (SERS) activity is fabricated on the tip of a glass nanopipette. Polystyrene (PS) nanospheres can be recognized from the SERS spectrum while passing through the single nanopore. [ABSTRACT FROM AUTHOR]

A metal-free intramolecular alkoxylation-initiated cascade cyclization of allyl ether-tethered ynamides has been developed. Various highly functionalized 3-isochromanones can be obtained in generally good to excellent yields under mild reaction conditions. Moreover, this asymmetric cyclization has also been realized via a stereocontrolled [3,3] rearrangement by employing a traceless chiral directing group. In addition, an unexpected [1,3] O-to-C rearrangement is observed in the case of the ynamide substrate bearing a phenyl-substituted alkene, which is distinctively different from the related gold catalysis. [ABSTRACT FROM AUTHOR]

Understanding the ionic transport behaviour as well as temperature change caused by the Joule heating effect is important for the application of plasmonic nanopores. To explore the basic properties of ionic transport through nanopores, we assemble gold nanoparticles on the tip of a glass nanopipette to form a hydrophilic gold porous structure (hydro-GPS) that exhibits high Raman activity. [ABSTRACT FROM AUTHOR]

A novel zinc-catalyzed reaction of isoxazoles with thioynol ethers involving an unprecedented 1,2-sulfur migration has been developed, which represents the first example of a non-noble metal-catalyzed reaction between isoxazoles and alkynes. This method allows the facile and atom-economical synthesis of a range of valuable β-keto enamides. Moreover, the computational study provides further evidence for the feasibility of the proposed reaction mechanism. [ABSTRACT FROM AUTHOR]

A novel dual gold/photoredox-catalyzed bis-arylative cyclization of chiral homopropargyl sulfonamides with diazonium salts has been developed, allowing the facile synthesis of various enantioenriched 2,3-dihydropyrroles in generally moderate to good yields with excellent enantioselectivities under very mild conditions without using any strong oxidants. The reaction is proposed to undergo an AuI/AuIII redox cycle promoted by visible-light photoredox catalysis. [ABSTRACT FROM AUTHOR]

Insoluble lead(ii) ethylenediaminetetraacetate isomers [Pb2(EDTA)(H2O)]2n (1) and [Pb4(EDTA)2]n·2nH2O (2) and allomers Pbn[Pb(EDTA)Pb(H2O)X]2n·2nH2O (X = Cl, 3 and Br, 4) are isolated from the reactions of lead nitrate with ethylenediaminetetraacetic acid in acidic solution (H4EDTA = ethylenediaminetetraacetic acid). The four complexes are fully characterized via elemental analysis, FT-IR spectroscopy, thermogravimetric analyses, solid state 13C NMR spectroscopy and X-ray crystal structure analyses. Topological analyses of complexes 2 and 3(4) show unusual (6,8)-connected 2-nodal and (4,5,6)-connected 3-nodal network topologies, respectively. The insertions of chloride and bromide in 3 and 4, respectively, give new polymeric lead–EDTA complexes. Products 3 and 4, which are obtained at room temperature, show a significant halide-assisted formation effect of insoluble ethylenediaminetetraacetato lead(ii) complexes, which is supported by solid state NMR and X-ray crystal structure analyses. [ABSTRACT FROM AUTHOR]

A direct gold-catalyzed 5-endo-dig cycloisomerization of chiral homopropargyl sulfonamides has been developed. A range of enantioenriched 2,3-dihydropyrroles are readily accessed by utilizing this approach. Importantly, this gold-catalyzed cycloisomerization reaction proceeds through an anti-Markovnikov addition by using a catalytic base as the additive, which completely suppresses the undesired dimerization. [ABSTRACT FROM AUTHOR]

A novel gold-catalyzed intermolecular oxidation of o-alkynylbiaryls has been developed. A variety of functionalized fluorenes are readily accessed by utilizing this non-diazo approach, thus providing a viable alternative to synthetically useful fluorenes. [ABSTRACT FROM AUTHOR]

A novel gold-catalyzed intermolecular oxidation of o-ethynylanilines has been developed. A range of functionalized 3-oxyindoles are readily accessed by utilizing this strategy. Importantly, this gold-catalyzed oxidative process outcompetes the typical indole formation. [ABSTRACT FROM AUTHOR]

Specially shaped high-nuclear lanthanide cluster assembly has attracted widespread attention, but the study of their self-assembly mechanism is still stagnant. Herein, we used a polydentate chelating bis-acylhydrazone ligand to construct a rare 16-nuclear dysprosium cluster 1 with a brucite-like structure. The capture agents, pivalic acid and di(pyridin-2-yl)methanone, were added into the reaction system, and the hexanuclear dysprosium cluster 2 and heptanuclear dysprosium cluster 3 were obtained, respectively. Clusters 2 and 3 support the out-to-in growth mechanism as key evidence. To the best of our knowledge, this study is the first to use truncation reaction to decipher the formation mechanism of high-nuclear lanthanide clusters.

The most effective way to understand reaction mechanisms and kinetics is to identify the reaction intermediates and determine the possible reaction patterns. The influencing factors that must be considered in the self-assembly of clusters are the type of ligand, metal ion, coordination anion and the pH of the solution. However, changes in ligand substituents resulting in different self-assembly processes to obtain different types of structures are still very rare, especially with -H and -CH 3 substituents, which do not exert significant steric hindrance effects. In this study, planar mononuclear Ni(L 1 ) 2 (L 1 = 2-ethoxy-6-(iminomethyl)phenol) was dissolved in methanol and combined with Dy(NO 3 ) 3 ·6H 2 O for 48 h at room temperature to obtain a butterfly-like Ni 2 Dy 2 cluster ([Dy 2 Ni 2 (L 1 ) 4 (CH 3 O) 2 (NO 3 ) 4 ], 1). The Dy(iii) ions in cluster 1 are in an O 8 N coordination environment, and the Ni(ii) ions are in an O 5 N coordination environment. High-resolution electrospray ionization mass spectrometry (HRESI-MS) was used to track species changes during the formation of cluster 1. Six key intermediate fragments were screened, and the self-assembly mechanism was proposed as Ni(L 1 ) 2 → HL 1 + NiL 1 → DyL 1 /Ni(L 1 ) 2 '→ DyNi(L 1 ) 2 → Dy 2 Ni 2 (L 1 ) 4 . Through this assembly mechanism, we found that Ni(L 1 ) 2 was first cleaved into HL 1 + NiL 1 and then further assembled to obtain 1. Another butterfly-like tetranuclear heterometallic cluster ([Dy 2 Ni 2 (L 2 ) 4 (CH 3 O) 2 (NO 3 ) 4 ], 2) was obtained using planar mononuclear Ni(L 2 ) 2 (L 2 = (E)-2-ethoxy-6-((methylimino)methyl)phenol) with -CH 3 substitution on the nitrogen atom under the same reaction conditions. The structural analysis of cluster 2 showed that the Dy(iii) ions are in an O 9 coordination environment, and the Ni(ii) ions are in an O 4 N 2 coordination environment. HRESI-MS was used to trace species changes during the formation of 2, and the assembly mechanism was proposed as Ni(L 2 ) 2 → DyNi(L 2 ) 2 → Dy 2 Ni(L 2 ) 2 → Dy 2 Ni 2 (L 2 ) 4 . Analysis of the assembly mechanism of 2 showed that Ni(L 2 ) 2 was twisted during the reaction, and its coordination point was exposed to capture the Dy(iii) ions. Finally, Dy(NO 3 ) 3 ·6H 2 O was replaced with NaN 3 to obtain a [Ni 2 Na 2 (L 2 ) 4 (N 3 ) 4 ] cluster (3) under the same reaction conditions and verify the above-mentioned torsion step. HRESI-MS was also used to trace the assembly process, and the assembly mechanism was proposed as Ni(L 2 ) 2 → NiNa(L 2 ) 2 → NiNa 2 (L 2 ) 2 → Ni 2 Na 2 (L 2 ) 4 . Herein, the effect of interference from substitution and the regulation self-assembly process were discovered in the formation of 3d-4f heterometallic clusters, and different types of coordination clusters were obtained.

Algae oil, enriched with omega-3 long-chain polyunsaturated fatty acids (ω-3 LC-PUFA), is known for its health benefits. However, protection against lipid oxidation as well as masking of unpleasant fishy malodors in algae oil enriched foods is a big challenge to achieve. In this study, we firstly achieved a one-pot ultrasound emulsification strategy (alternative heating-homogenization) to prepare phytosterol structured thermosensitive algae oil-in-water nanoemulsion stabilized by quillaja saponin. After spray drying, the resulting algae oil powders from the structured nanoemulsion templates exhibit an excellent reconstructed behavior, even after 30 d of storage. Furthermore, an enhanced oxidative stability was obtained by reducing both the primary and secondary oxidation products through formulation with β-sitosterol and γ-oryzanol, which are natural antioxidants. Following the results of headspace volatiles using dynamic headspace-gas chromatography-mass spectrometry (DHS-GC-MS), it was clear that the structured algae oil-loaded nanoemulsion and powder had lower levels of fishy off-flavour (e.g., (Z)-heptenal, decanal, ethanone, and hexadecenoic acid), whereas the control emulsion and oil powder without structure performed worse. This study demonstrated that the structure from phytosterols is an effective strategy to minimize the fishy off-flavour and maximize oxidative stability of both algae oil nanoemulsions and spray-dried powders, and opens up the possibility of formulation design in polyunsaturated oil encapsulates as novel delivery systems to apply in functional foods and beverages.

A novel gold-catalyzed intermolecular oxidation of o-alkynylbiaryls has been developed. A variety of functionalized fluorenes are readily accessed by utilizing this non-diazo approach, thus providing a viable alternative to synthetically useful fluorenes.

A novel gold-catalyzed intermolecular oxidation of o-ethynylanilines has been developed. A range of functionalized 3-oxyindoles are readily accessed by utilizing this strategy. Importantly, this gold-catalyzed oxidative process outcompetes the typical indole formation.

Soy lipophilic protein nanoparticles (LPP), which present a novel delivery vehicle for conjugated linoleic acid (CLA), were fabricated by ultrasonication of the soy lipophilic protein (LP), which exhibits unique characteristics including a high loading capacity, oxidation protection and a sustained releasing profile in vitro for CLA. The CLA-loaded LPP exhibited a mean diameter of 170 ± 0.63 nm and a loading capacity of 26.3 ± 0.40% (w/w). A coating of sodium caseinate (SC) on the surface improved the colloidal stability of the CLA-loaded LPP. This encapsulation conferred protection against the oxidation of CLA, by which the head space-oxygen consumption and hydrogen peroxide value were obviously decreased in comparison with the SC-encapsulated CLA and CLA alone. The delivery system enables a sustained releasing profile of CLA in a simulated gastrointestinal tract (GIT). These findings illustrate that the LPP could act as an effective delivery device for CLA, which could provide oxidation stability and a sustained release property.