Underpotential Deposition‐Induced Synthesis of Composition‐Tunable Pt?Cu Nanocrystals and Their Catalytic Properties

Pt? Cu alloy octahedral nanocrystals (NCs) have been synthesized successfully by using N,N‐dimethylformamide as both the solvent and the reducing agent in the presence of cetyltrimethylammonium chloride. Cu underpotential deposition (UPD) is found to play a key role in the formation of the Pt? Cu alloy NCs. The composition in the Pt? Cu alloy can be tuned by adjusting the ratio of metal precursors in solution. However, the Cu content in the Pt? Cu alloy NCs cannot exceed 50 %. Due to the fact that Cu precursor cannot be reduced to metallic copper and the Cu content cannot exceed 50 %, we achieved the formation of the Pt? Cu alloy by using Cu UPD on the Pt surface. In addition, the catalytic activities of Pt? Cu alloy NCs with different composition were investigated in electrocatalytic oxidation of formic acid. The results reveal that the catalytic performance is strongly dependent on Pt? Cu alloy composition. The sample of Pt₅₀Cu₅₀ exhibits excellent activity in electrocatalytic oxidation of formic acid.     

One‐Pot,Template‐Free Synthesis of Pd?Pt Single‐Crystalline Hollow Cubes with Enhanced Catalytic Activity

Hollow structures have attracted ever‐growing interest owing to their various excellent properties. However, a facile strategy for their fabrication is still desired. Herein, Pd? Pt alloy with three different morphologies, that is, cubes, hollow cubes, and truncated octahedrons, is synthesized by using a one‐pot, template‐free method. The mechanism and dynamics of this system is also studied in detail. In particular, the hollow cubic structure represents enhanced catalytic activity in both coupling reactions and in the electrochemical oxidation of formic acid.     

Synthesis and Characterization of Polymer Brushes Containing β-Cyclodextrin Grafted to Magnetic Nanoparticles for Determination of Naproxen in Urine

β-Cyclodextrin containing polymer brushes were grafted to magnetic nanoparticles following free radical copolymerization of N,N-dimethylacrylamide and allyl glycidyl ether on the surface. The products were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, elemental analysis, and transmission electron microscopy and employed for solid phase extraction of naproxen in human urine. The profile of the naproxen adsorbed by the nanoparticles demonstrated high accessibility of the β-cyclodextrin. Scatchard analysis indicated that the capacity of the nanoparticles was 112 µmol g^?1 at 25°C and a pH of 5. The adsorption data of naproxen were considered by Langmuir, Freundlich, Redlich–Peterson, and Temkin isotherms. Approximately 55% of naproxen was released in simulated gastric fluid in 30 min and 94% in simulated intestinal fluid in 30 h. These data have indicated the utility of the naproxen loaded- β-cyclodextrin containing polymer brushes grafted to magnetic nanoparticles for enteric drug delivery.     

Synthesis and Antimalarial‐Activity Evaluation of Tetraoxane?Triazine Hybrids and Spiro[piperidine‐4,3′‐tetraoxanes]

A series of tetraoxane? triazine hybrids and spiro[piperidine‐4,3′‐tetraoxanes] have been synthesized, and all the compounds were screened for in vitro antimalarial activity against chloroquine‐sensitive (D6) and chloroquine‐resistant (W2) strains of Plasmodium falciparum. Most of the spiro[piperidine‐4,3′‐tetraoxanes] exhibited moderate to good antimalarial activities, and two compounds have shown good antimalarial activity with IC₅₀ values in the range of 0.30 to 0.70 μM against both the strains with high selectivity index and no cytotoxicity towards mammalian kidney cell line.     

Synthesis and Ionic Conductivity of Network Polymer Electrolytes with Internal Plasticizers

Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.     

Catalytic Synthesis of Ammonia—A “Never‐Ending Story”?

Nitrogen atoms are essential for the function of biological molecules and thus are and important component of fertilizers and medicaments. Bonds to nitrogen also find nonbiological uses in dyes, explosives, and resins. The synthesis of all these materials requires ammonia as an activated nitrogen building block. This situation is true for natural processes and the chemical industry. Knowledge of the various techniques for the preparation of ammonia is thus of fundamental importance for chemistry. The Haber-Bosch synthesis was the first heterogeneous catalytic system employed in the chemical industry and is still in use today. Understanding the mechanism and the translation of the knowledge into technical perfection has become a fundamental criterion for scientific development in catalysis research.     

Synthesis of Catechol‐, Pinacol‐, and Neopentylglycolborane through the Heterogeneous Catalytic B?B Hydrogenolysis of Diboranes(4)

A new synthetic approach to hydroboranes catechol‐, pinacol‐, and neopentylglycolborane has been developed. Starting from diboranes(4) B₂cat₂, B₂pin₂, or B₂neop₂, the respective boranes were obtained by heterogeneously catalyzed cleavage of the B? B bond in the respective diboranes with hydrogen. Group 10 metals were found to be effective catalysts for this reaction.     

Synthesis and Conductivity of a One-dimensional Polymer of a Copper(Ⅱ)-porphyrazine with Sulfur Bridges

Phthalocyanines(Pcs)andtheirpolyinershavebeenasubjectofgreatinterestduetotheirhighthermalstabilityanduniquephotoelectricpropertiesl4.Ithasbeenfoundthatsomeelectronicfunctionsofthemetalthioporphyrazinesandtheirconjugatedpolymers,suchasgas-sensitivityphotosensitivity,photoconductivityandelectrocatalyticactivity,aremorepeculiarthancorrespondingPcs5'6.Oneofourinterestsistodesignanovelpolymerofmetalporphyrazines(PMPzs)withswitchingpointsunderthecontrolofachangingexternalfieIdorenvironment.Inthepr…     

Controllable Synthesis of Porphyrin-Based 2D Lanthanide Metal–Organic Frameworks with Thickness- and Metal-Node-Dependent Photocatalytic Performance

Synthesizing 2D metal–organic frameworks (2D MOFs) in high yields and rational tailoring of the properties in a predictable manner for specific applications is extremely challenging. Now, a series of porphyrin-based 2D lanthanide MOFs (Ln-TCPP, Ln=Ce, Sm, Eu, Tb, Yb, TCPP=tetrakis(4-carboxyphenyl) porphyrin) with different thickness were successfully prepared in a household microwave oven. The as-prepared 2D Ln-TCPP nanosheets showed thickness-dependent photocatalytic performances towards photooxidation of 1,5-dihydroxynaphthalene (1,5-DHN) to synthesize juglone. Particularly, the Yb-TCPP displayed outstanding photodynamic activity to generate O₂⁻ and ¹O₂. This work not only provides fundamental insights into structure designing and property tailoring of 2D MOFs nanosheets, but also pave a new way to improve the photocatalytic performance.     

Side‐Product of N‐Acryloyloxysuccinimide Synthesis or Useful New Bifunctional Monomer?

During the synthesis of the N‐acryloxysuccinimide (NAS) monomer, we observed the formation of a by‐product, resulting from the condensation of two NAS molecules via a Michael addition. Due to its bulky structure, this new bifunctional monomer shows a very poor ability to homopolymerize. On the contrary, it readily copolymerizes with N‐acryloylmorpholine (NAM), an hydrophilic acrylamide derivative, leading to functional polymer chains exhibiting a wide range of solubility and a high potential for biomolecule covalent binding.     

Polymer Surfactants a; Analytical Reagents——Synthesis of PPOTA and PPOCA and Their Analytical Properties

Two new polymer surfactants poly(propylene oxide)-a-tetradecyl-dimethylammonium chloride(PPOTA) and poly(propylene oxide)-a-cetyl-dimethylammonium chloride(PPOCA) were synthesized,which possess the characteristics of both cationic and nonionic surf actants.The properties of PPOTA and PPOCA were investigated.The synthesized surfactants can be used as sensitizing and solubilizing reagents for spectrophotometric analysis.Some examples of micellae improved by spectrophotometric systems such as Sc(Ⅲ)-CAS,Ge(Ⅳ)-PF and Ni(Ⅱ)-CAS were given.     

Why are reactions of 2‐ and 8‐thioquinoline derivatives with iodine different?

The crystal structures of 1,2‐dihydro‐1,1′‐bi[thiazolo[3,2‐a]quinoline]‐10a,10a′‐diium diiodide hemihydrate, C₂₂H₁₆N₂S₂²⁺·2I⁻·0.5H₂O, and 1,2‐dihydro‐1,1′‐bi[thiazolo[3,2‐a]quinoline]‐10a,10a′‐diium iodide triiodide, C₂₂H₁₆N₂S₂²⁺·I⁻·I₃⁻, obtained during the reaction of 1,4‐bis(quinolin‐2‐ylsulfanyl)but‐2‐yne (2TQB) with iodine, have been determined at 120 K. The crystalline products contain the dication as a result of the reaction proceeding along the iodocyclization pathway. This is fundamentally different from the previously observed reaction of 1,4‐bis(quinolin‐8‐ylsulfanyl)but‐2‐yne (8TQB) with iodine under similar conditions. A comparative analysis of the possible conformational states indicates differences in the relative stabilities and free rotation for the 2‐ and 8‐thioquinoline derivatives which lead to a disparity in the convergence of the potential reaction centres for 2TQB and 8TQB.     

Synthesis and Crystal Structure of a New Cadmium（Ⅱ） Coordination Polymer with Ethylenediaminetetraacetic Acid

A new cadmium(Ⅱ) coordination polymer,namely,[KCd2(edta)I]n(1,H4edta = ethylenediaminetetraacetic acid),has been prepared and structurally characterized by single-crystal X-ray diffraction.Crystallographic data for 1:C10H12Cd2IKN2O8,Mr = 679.02,monoclinic,space group P21/n,a = 9.870(5),b = 8.989(4),c = 19.082(10) ,β = 104.581(10)o,V = 1638.5(13) 3,Z = 4,Dc = 2.753 g/cm3,μ = 4.776 mm-1,F(000) = 1272,the final R = 0.0473 and wR = 0.1311 for 2846 observed reflections with I > 2σ(I).Polymer 1 features a 2-D layered structure,in which each edta4-ligand chelates/bridges five adjacent six-/seven-coordinated Cd(Ⅱ) centers with all ten donors(eight oxygen and two nitrogen) involved with coordination.Additional iodide I-ions as counterions are bound to the Cd(Ⅱ) centers in a terminal mode and the potassium K+ ions are located in the layers and surrounded by O and I atoms from neighboring environment.The thermal stability of 1 has been discussed.     

Synthesis and Crystal Structure of a Novel Cobalt（Ⅱ） Coordination Polymer with 1,2,4,5-Benzenetetracarboxylate

A novel cobalt（II） coordination polymer,[Co（BTEC）1/2]n 1,has been synthesized with Co（NO3）2·6H2O and 1,2,4,5-benzenetetracarboxylic acid （H4BTEC） by the hydrothermal method,and characterized by elemental analysis,IR and single-crystal X-ray diffraction. Crystallographic data for 1： C5HO4Co,Mr = 183.99,monoclinic,space group C2/c,a = 16.619（6）,b = 7.416（3）,c = 8.040（3）A,β = 90.612（4）°,V = 990.8（6） A^3,Z = 8,Dc = 2.467 g/cm^3,μ = 3.390 mm^-1,F（000） = 720,R = 0.0307 and wR = 0.0847 for 912 observed reflections （I 〉 2σ（I））. X-ray crystal structural analysis revealed that each Co（II） adopts a tetrahedral coordination mode to link four separate BTEC ligands via uniform monodentate carboxylate groups and each BTEC ligand possesses an 8-connected geometry to connect eight Co（II） ions. Complex 1 exhibits a rare （4,8）-connected net with （45.6）2（410.614.84） topology.     

Synthesis and Crystal Structure of a Novd Nickel (Ⅱ) Coordination Polymer with Chiral Schiff-base

以手性对称的Shiff碱为配体,合成了手性镍配合物[Ni2(salen)2(1)],其结构经X-单晶射线衍射和元素分析表征.1属单斜晶系,C2空间群,晶胞参数a ＝25.060(5)(A),b=13.508(3)(A),c＝ 11.938(2)(A),α=90(3)°,β=104.82(3)°,γ=90(3)°,V=3906.7(14)(A)3,Z=4,Mr=828.24,Dc=1.429 g·cm-3,F(000)=1808,μ=1.027mm-1,GOF=1.068,R1=0.051 0,wR2=0.1289.在1的分子结构中,环己胺和苯环之间通过分子间CH…π作用形成二维结构.     

Synthesis and Crystal Structure of a One-dimensional Silver(Ⅰ) Coordination Polymer with 4,4'-Bipyridine

The title compound,{[Ag2(bipy)2(H2O2]·pydc·2H2O}n(bipy=4,4'-bipyridine,pydc=pyridine-3,5-dicarboxylate),has been synthesized by the reaction of Ag2O with pydc and bipy in CH3OH solution.It crystallizes in the monoclinic system,space group C2/c with a=21.419(8),b=7.515(3),c=18.070(7)(A),β=108.273(6)°,Mr=765.27,V=2761.9(17)(A)3,Z=4,Dc=1.840 g/cm3,F(000)=1528,μ=1.478 mm-1,the final R=0.0307 and wR=0.0681.The structure determined demonstrated that the Ag(Ⅰ)is three-coordinated by two nitrogen atoms from bipy and one water molecule,forming a one-dimensional coordination polymer[Ag2(bipy)2(H2O)2]n2n ,which is further linked to generate a two-dimensional layer structure via Ag…Ag attractions.     

Synthesis,Structural Characterization and Catalytic Activity of Copper(Ⅰ) Complexes with Triphenylphosphine and Pyridine Derivatives

Two new Cu(Ⅰ) complexes [CuCl(3-PyOH)(PPh_3)_2](1) and [Cu_2(μ-Cl)_2(4-Stpy)(Ph_3P)_3](2)(PyOH = hydroxypyridine; stpy = styrylpyridine) with triphenylphosphine and pyridine derivatives have been synthesized and characterized by elemental analysis and X-ray single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group P2_1/c with a = 9.8945(7), b = 37.266(2), c = 10.9461(7) ?, β = 116.0750(10)°, V = 3625.3(4) ?~3, Z = 4, D_c = 1.350 Mg/cm~(-3), μ = 0.801 mm~(-1), F(000) = 1528, the final R = 0.0320 and w R = 0.0729 for 18568 observed reflections(I 2σ(I)), R(all data) = 0.0413, wR(all data) = 0.0769, completeness to theta of 25.01 is 99.9% and GOF = 1.037. Compound 2 crystallizes in monoclinic, space group P2_1/c with a = 11.290(3), b = 20.388(5), c = 24.092(6) ?, β = 102.028(4)°, V = 5424(2) ?~3, Z = 4, D_c = 1.428 Mg/cm~(-3), μ = 1.016 mm~(-1), F(000) = 2408, the final R = 0.0568 and w R = 0.1486 for 27644 observed reflections(I 2σ(I)), R(all data) = 0.0716, wR(all data) = 0.1592, completeness to theta of 25.01 is 99.9% and GOF = 1.056. Two new Cu(I) complexes have been utilized as catalysts for N-arylation of imidazole and both showed good catalytic activity.