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Intrinsic dual-emission (DE) of gold nanoclusters in the near-infrared (NIR) are fascinating for fundamental importance and practical applications, but their synthesis remains a formidable challenge and sophisticated excited-state processes make elucidating DE mechanisms much more arduous. Here, we report an all-alkynyl–protected gold nanocluster, Au20 , showing a prolate Au 12 tri-octahedral kernel surrounded by two Au 2 (CZ-PrA) 3 dimers, four Au(CZ-PrA) 2 monomers, and two CZ-PrA − bridges. Au20 exhibits distinguished photophysical properties including NIR DE at 820 and 940 nm, microsecond radiative relaxation, and 6.26% photoluminescent quantum yield at ambient environment in nondegassed solution. Combining systematic studies on steady/transient spectroscopy and theoretical calculation, we identified two triplet charge transfer (CT) states, ligand-to-kernel and kernel-based CT states as DE origins. Furthermore, this NIR DE exhibits highly independent and sensitive response to surrounding environments, which well coincide with its mechanism. This work not only provides a substantial structure model to understand a distinctive DE mechanism but also motivates the further development of NIR DE materials.

An eosin Y-catalyzed annulation reaction of cyclic N-sulfonyl ketimines and N-arylglycines was reported to construct N-sulfonamide-fused imidazolidines under visible-light induced metal-free conditions.

An efficient strategy to aryl-heteroaryl formation via RhIII-catalyzed C–H heteroarylation of arenes with N-heterocyclic boronates has been disclosed.

A carboxylate-assisted iridium(III)-catalyzed regioselective C(sp

In this work, a novel 4-aminophenylarsonic acid functionalized polyoxovanadates (POVs) hybrid material, namely, (Me2NH2)4 ·[(L)8(H12V16O32)] (H2L = 4-NH2C6H4AsO3H2) POVs 1 was solvothermally synthesized and fully characterized. The results revealed POVs 1 consists of four similar tetranuclear vanadium clusters bridged by eight organic 4-aminophenylarsonic acid ligands. Remarkably, functionalized hybrid POVs 1 was further investigated as a heterogeneous stable catalyst in oxidation of sulfide derivatives, and exhibited high catalytic activities (yields up to 96.7%). Additionally, the functionalized hybrid polyoxovanadates catalyst can be reused without losing activities after three runs cycle.

With the increasing interest in polyoxometalates (POMs) materials over the past few decades, scientific researchers have focused their attention on the fruitful utilization of POMs hybrids as efficient catalysts in many organic reactions. In this paper, dipyridine amine (dpa) organic ligand hybrid polyoxomolybdate material was solvothermally synthesized and structurally identified by elemental analysis, X-ray diffraction and infrared spectrum. Structural refinement of the hybrid polyoxomolybdate compound 1 with general formula [Hdpa]4Mo8O26 · 2DMF (DMF = N,N-dimethylformamide) shows that compound 1 presents in the space group P-1 with triclinic system, and is built up from a well-known β-[Mo8O26]4– anionic cluster, four free protonated dpa cations and two free DMF molecules. Remarkably, the β-Mo8O26-based hybrid material was further applied as the catalyst in the conversion of sulfides utilizing hydrogen peroxide (30%) as green terminal oxidant and exhibited efficient catalytic activities for selective oxidation of sulfides.

1-Acryloyl-2-cyanoindoles were found to be novel and efficient skeletons in visible-light-induced persulfate-promoted cascade cyclization reactions. With this transition-metal-free photocatalytic procedure, various sulfonated/thiocyanated pyrrolo[1,2

It is well known that structure determines property, but obtaining a pair of silver nanoclusters with comparable structures to understand the structure-property relationship is a very challenging task. A new 60-nuclei silver nanocluster (SD/Ag60a) protected by a mixed-ligand shell of

Polyoxometalate (POM) cluster organic frameworks (POMCOFs) are an emerging class of catalytic materials, providing an opportunity to develop fascinating catalysts with well-defined, tunable, active sites for a range of chemical transformations. Although remarkable progress on numerous POMCOF materials has been reported, the synthesis of polyoxovanadate (POV) cluster organic frameworks (POVCOFs) has seldom been reported. Thus, the exploration of novel POVCOFs still attracts considerable research interest. Additionally, Knoevenagel condensation as a versatile tool for the construction of CC bonds still continues to be a challenge at room-temperature and under solvent-free conditions. Herein, three POV-based clusters, [Ni(1-bIm)4]2(V4O12)·H2O (1), [Ni(1-eIm)(H2O)4]2(V10O28)(1-eImH)2·2H2O (2) and [Ni(H2O)5]2(V10O28)(1-pImH)2·4H2O (3) (1-bIm = 1-butylimidazole; 1-eIm = 1-ethylimidazole and 1-pIm = 1-propylimidazole), have been made. 1 was controllably achieved by an imidazole-induced self-assembly strategy and exhibited a 2D POVCOF in which circular [V4O12]4− clusters are bridged by four six-coordinated Ni(II) atoms (NiN4O2 model). 2 and 3 are obtained at lower pH values. Notably, among the three POV-based clusters, POVCOF 1 displays highly efficient heterogeneous solvent-free catalytic activity (yields of up to 99%) and excellent recyclability in Knoevenagel condensation at room temperature.

By the combination of Ag-complexes and Keggin POMs, two novel inorganic–organic silver–polyoxometalates hybrids, [Ag3L2(DMSO)2][PW12O40]·4DMSO (1) and [(Ag2L2)2][SiW12O40]·10DMSO·2H2O (2) (L = 4-(2-pyridyl)-6-(4-pyridyl)-2-aminopyrimidine), were synthesized and characterized. Interestingly, the silver atoms in compound 1 are three-coordinated with the AgNO model; however, the Ag atoms of compound 2 were surrounded by four N atoms of the organic ligands and displayed a distorted tetrahedral configuration. Importantly, compound 1 showed high catalytic activities for the three-component coupling reaction of alkynes and secondary amines along with formaldehyde, which resulted in a series of propargylamine derivatives in higher yields (up to 99%). Furthermore, the Ag–POM catalyst was easily recovered by filtration and reused for three cycles without a significant loss in catalytic activity. A tentative mechanism is also proposed for this transformation.

A non-corrosive, recyclable and efficient heterogeneous catalyst based on Keggin-type polyoxometalate, i.e., [NMPH]H3[SiW12O40] was developed for the direct dehydrative coupling of alcohols with alcohols (or alkenes) to synthesize various polysubstituted olefins in good to excellent yields. Furthermore, this reaction could be scaled up and the catalyst could be used for seven runs without significant loss of activity. The kinetic competition experiment shows that the C–H bond cleavage might be involved in the rate-determining step.

The Co(ii)-catalyzed selective C-H alkenylation of picolinamides with 1,3-diynes has been developed. This protocol can be applied to a variety of 1,3-diynes. In addition, both symmetrical and unsymmetrical internal alkynes were well tolerated, affording the corresponding alkenyl arenes. Moreover, control experiments indicated that C-H bond cleavage may be involved in the rate-determining step. Furthermore, a deuterium incorporation product was achieved when deuterated alcohol was employed as the solvent, which suggested that alcohol was essential for the final protonolysis.

A metal-free cascade reaction was developed for the synthesis of indolo[1,2-a]quinoline derivatives from arylsulfonyl hydrazides and 1-(2-(arylethynyl)phenyl)indoles in the presence of TBAI/TBHP. Impressively, these products exhibit excellent fluorescence properties, which is promising for cell imaging.

A simple and efficient decarboxylative radical addition/cyclization strategy was developed, by which a wide range of benzimidazo[2,1-a]isoquinoline-6(5H)-ones were prepared in one-pot via reaction of functionalized 2-arylbenzoimidazoles and carboxylic acids in the presence of K2S2O8/AgNO3 under mild reaction conditions.

The cobalt-catalyzed regioselective C H alkoxylation of 1-naphthylamide with diols through a bidentate-chelation assistance has been developed. In this transformation, not only linear diols, but also branched diols and oligoethylene glycols were tolerated under current reaction conditions, affording the corresponding hydroxyalkyl aryl ethers. In addition, control experiments suggested that picolinoyl was the key directing group, and furthermore, this C8-H alkoxylation reaction might proceed through a single-electron-transfer (SET) process.

Carbon dioxide (CO2) is the largest contributor to the greenhouse effect, and fixing and using this greenhouse gas in a facile manner is crucial. This work investigates the electrocarboxylation of dichlorobenzenes with the atmospheric pressure of CO2 in an undivided cell with an Ag cathode and an Mg sacrificial anode. The corresponding carboxylic acids and their derivatives, which are important industrial and fine chemicals, are obtained. To deeply understand this reaction, we investigate the influence of various reaction conditions, such as supporting electrolyte, current density, electric charge, and reaction temperature, on the electrocarboxylation yield by using 1,4-dichlorobenzene as the model compound. The electrochemical behavior of dichlorobenzenes is studied through cyclic voltammetry. The relation among the distinct electronic effects of dichlorobenzenes, the electrochemical characteristics of their reduction, and the distribution law of target products is also established.

The two-state reaction (TSR) mechanism of CpCo(C4H4) with isocyanate on the triplet and singlet potential energy surfaces has been investigated at the B3LYP level. The minimal energy crossing point (CPs) in the crossing seam between the potential energy surfaces are located using the method of Harvey et al., and possible spin inversion processes are discussed by means of spin–orbit coupling (SOC) calculations. As a result, the two distinct reaction pathways for the formation of a pyridin-2-one cobalt complex have been found. For the first pathway, there are two key crossing points along the reaction pathway. The first crossing point, CP2, exists near 1B. The reacting system will change its spin multiplicity from the triplet state to the singlet state near this crossing region because the magnitude of the spin-multiplicity mixing (SOC1-e,1-center = 393.37 cm–1) increases in a small energy gap between high- and low-spin states will greatly enhance the probability of intersystem crossing. The single (P1ISC) ...

An efficient, mild and fast procedure for the preparation of title series (III) is reported.

FeCl₃-mediated oxidative cyclization was successfully used to construct an extended thiophene-pendant pyrene skeleton and synthesize a novel thiophene-fused polycyclic aromatic (THTP-C) with a tetracene core. The identity of the compound was confirmed by ¹H-NMR, ¹³C-NMR, MS, and elemental analysis. Meanwhile, a single crystal of THTP-C was obtained and analyzed by X-ray single-crystal diffraction. THTP-C has a "saddle" shaped π-conjugated 1-D supramolecular structure, and favors highly ordered self-assembly by π-π interactions as evidenced by its concentration-dependent ¹H-NMR spectra in solution. The optical properties of THTP-C were investigated by ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy and its electrochemical properties were investigated by cyclic voltammetry (CV). The relatively large band gap (2.86 eV), low E(HOMO) level (-5.64 eV) and intermolecular π-π interactions imply that THTP-C has a high stability against photo-degradation and oxidation, and may be a promising candidate for stable hole-transporting materials.

A lanthanide coordination complex [Eu(PAA)2(phen)(NO3)]2 (PAA = phenylacetic acid, phen = 1,10-phenanthroline) has been synthesized by the hydrothermal method. Single crystal X-ray diffractions show that it forms a dimeric molecular structure. The title complex crystallizes in the triclinic system, space group P 1, with lattice parameters a = 8.9473(8) A, b = 13.3659(12) A, c = 13.4745(12) A, α = 60.7590(10)°, β = 89.5100(10)°, γ = 71.9850(10)°, V = 1317.3(2) A3, D c = 1.675 Mg m−3, Z = 1, F(000) = 660, GOF = 1.003, R 1 = 0.0206, wR 2 = 0.0575. The fluorescence excitation and emission spectra have been investigated.

The manganese coordination compound [Mn(dcb)(H2O)4] n has been obtained by hydrothermal synthesis by using Mn(CH3COO)2 · 2H2O and 1,10-phenanthroline-5,6-dione, where dcb = 3,3′-dicarboxy-2,2′-bipyridine. The results of X-ray single-crystal diffraction reveal that the title complex forms a chain-like 1D structure. The complex [Mn(dcb)(H2O)4] n crystallizes in the orthorhombic system, space group P2(1)2(1)2, with lattice parameters a = 13.896(3) A, b = 6.3507(12) A, c = 8.3745(15) A, V = 739.1(2) A3, D c = 1.659 Mg m−3, Z = 2, F(000) = 378, GOF = 0.999, R 1 = 0.0283, wR 2 = 0.0719. The photophysical properties have been investigated with fluorescence excitation and emission spectra.

Donor–acceptor–donor oligomers with dibenzothiophene 5,5-dioxide core and end-cap phenylene–thiophene substitutes were newly synthesized. New oligomers were characterized by UV–vis absorption and p...

An efficient, mild and fast procedure for the preparation of title series (III) is reported.

Twelve 3, 5-diarylpyrazoles have been synthesized by microwave-assisted condensation reaction in a short and concise manner using various aromatic aldehydes and aromatic ketones as starting materials. The corresponding products were obtained in good yields (87-96%). All products were identified by MS, 1H NMR, 13C NMR and elemental analysis. The advantages of this novel protocol include the excellent yield, operational simplicity, short time and the avoidance of the use of expensive catalysts.

In the title compound, C(15)H(13)ClN(2)O(2), the dihedral angle between the two benzene rings is 7.0 (1)°. An intra-molecular N-H⋯O hydrogen bond is present and inter-molecular O-H⋯O hydrogen bonds link the mol-ecules into chains along [001].

In the title mol­ecule (systematic name: 10,26-dimethyl-2,5,8,15,18,21-hexa­oxatricyclo­[20.4.0.09,14]tetra­cosa-9,11,13,22,24,26-hexa­ene), C22H28O6, the two benzene rings make a dihedral angle of 63.9 (2)°, indicating a boat-like mol­ecular conformation. The crystal packing is mainly stabilized by van der Waals forces.

The title compound, C23H22O3, has been synthesized by the reaction of furfural with 4-methyl­acetophenone and NaOH. The bond lengths and angles have normal values. The crystal packing exhibits no significantly short inter­molecular contacts.

In the title compound, C21H18N2O2, synthesized by the reaction of benzaldehyde with 2-acetyl­pyridine and KOH, the phenyl ring makes dihedral angles of 88.5 (1) and 83.9 (1)° with the two pyridine rings. The crystal packing is stabilized by weak inter­molecular C—H⋯O hydrogen bonds, with an H⋯O distance of 2.47 A, and by van der Waals forces.

The title compound, C21H18O2S, was synthesized by the reaction of thio­phene-2-carbaldehyde with acetophenone and NaOH. All bond lengths and angles show normal values. The crystal packing is stabilized by weak inter­molecular C—H⋯O hydrogen bonds and van der Waals forces.

The title compound, C25H24O2, has been synthesized by the reaction of benzaldehyde with 4-methyl­acetophenone and NaOH. The bond lengths and angles show normal values. The crystal packing exhibits no significantly short inter­molecular contacts.

The title compund, C22H19NO2, was synthesized by the reaction of pyridine-2-carbaldehyde with acetophenone and NaOH. The bond lengths and angles show normal values. The crystal packing exhibits no significantly short inter­molecular contacts.

In the title molecule, C21H16Cl2O2S, the five-membered ring is rotationally disordered between two orientations in a 1:1 ratio. In the crystal structure, weak intermolecular C—H...O hydrogen bonds link molecules related by translation along the a axis into chains, which are further combined into layers parallel to the bc plane via C—H...π interactions. The crystal studied was a racemic twin with a 0.37 (19):0.63 (19) domain ratio.

The asymmetric unit of the title compound, C19H16O2S2, contains two independent molecules with slightly different conformations. In the crystal structure, weak intermolecular C—H...O hydrogen bonds [C...O = 3.279 (15) and 3.407 (16) Å] link the molecules into chains extended along the c axis.