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cis-4-Aryl-3-arylthio-3,4-dihydroquinolin-2(1H)-ones were synthesized via electrophilic sulfenylation and cyclization of N-arylcinnamamides with N-arylthiosuccinimides in the presence of boron trifluoride etherate. The cis-products were obtained with high stereoselectivity. [ABSTRACT FROM AUTHOR]

S-rich MoS2-NCNF hybrid nanomaterials exhibiting extraordinary HER activity, with a very low onset potential of 30 mV and a small Tafel slope of 38 mV per decade, were successfully fabricated by combining N-doped carbon nanofibers and single-layered MoS2 nanostructures with abundant edge active sites. [ABSTRACT FROM AUTHOR]

An efficient route to 4-arylquinazolines via arylation of quinazolin-4-ones under mild condition is described. The reaction is carried out by the palladium-catalyzed coupling of quinazolin-4- ones with arylboronic acids in the presence of TsCl leading to 4-arylquinazolines in good to excellent yields. [ABSTRACT FROM AUTHOR]

The unique tetrapyridyl ligand 1,2,4,5-tetra(4-pyridyl)benzene (bztpy) isolated from previous hydrothermal in situmetal ligand reaction is found to exhibit remarkable anion-dependent assembly of a series of novel metal–organic frameworks (MOFs), [Cu2(CN)2(bztpy)] (1), [Cu(SO4)(bztpy)]·1.5H2O (2), [Cu2Br2(bztpy)]·MeCN (3) and [Cu10I10(bztpy)2]·2H2O (4), which were synthesized under hydro/solvothermal conditions. These MOFs were characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1consists of [Cu(CN)]nchains that link the neighbouring ones viatetradentate bztpy bridges to form a corrugated 2D layer. When bztpy is treated with CuSO4, a 3D (3,5)-connected network 2is obtained, in which novel [Cu(bztpy)]nladders are interconnected by sulfate anions μ-bridges. However, Br−and I−anions assist the formation of {Cu2Br2} and {Cu10I10} SBU in the cluster-based metal–organic frameworks 3and 4, respectively, and result in a completely different topology. Compound 3shows a 3D PtS net, while compound 4has a new 3D (4,8)-connected topology. A discussion of the crystal structures, as well as the coordination behaviour of the special tetrapyridyl ligand upon different geometries of the central connecter is provided. In addition, the photoluminescent properties of 1, 3and 4in the solid state at ambient temperature are also investigated. [ABSTRACT FROM AUTHOR]

Novel poly(ethylene–vinyl acetate) film with fluorinated surface structure was prepared via sequential surface reactions, which are alcoholysis reaction with sodium ethoxide and located fluorination reaction with 2,3,3,3-tetrafluoro-2-[1,1,2,3,3,3-hexafluoro-2-(heptafluoropropoxy)propoxy] propionyl fluoride, respectively. The obtained novel film possesses ordered perfluoroalkyl ether surface layer proved by detailed ATR-FTIR, XPS, and contact angle measurement, which substantiates the success of this new route to get better-tailored surface meeting the biological needs. Hemocompatibility of the resultant films was evaluated by hemolysis test and platelet adhesion test. The results indicated that the poly(ethylene–vinyl acetate) film surface displayed low hemolytic activity and no platelet adhesion due to its extremely low surface tension, which results from the special micro-electric field of perfluoroalkyl ether layer. The yielded transparent film with good properties exhibits a promising application prospect in biology and medical science in view of its flexible substrate and unique biocompatible surface. [ABSTRACT FROM AUTHOR]

The structural, vibrational and thermodynamic properties of β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (β-HMX) crystal have been studied using the isothermal-isobaric molecular dynamics (NPT-MD) simulations. The variations of cell volume, lattice constants and molecular geometry of solid β-HMX are presented and discussed at different pressure and temperature. It was found that the N-N bond is significantly lengthened with increasing temperature, which suggests that it is relevant to the initial decomposition. An abrupt change at 27 Gpa for the volume and internal geometrical parameters was observed. This is in good accord with the experimental observation that there is a phase transition at 27 GPa, which is clearly due to conformational change, not chemical reaction. The vibrational frequencies at ambient conditions agree well with experimental results, and the pressure/temperature-induced frequency shifts of these modes are discussed. Frequency discontinuity was also observed at pressure when the phase transition occurred. The Gruneisen parameter was obtained using the vibrational frequency. [ABSTRACT FROM AUTHOR]

Solvothermal treatment of a mixture of Co(OAc)2, NaN3, NaN(CN)2, HF, MeCN, and H2O generated an AlB2-like metal-organic framework, namely, [{(CO3F)3(trta)2(H2O)9}{Co(Hbta)3}2]· 11H2O (1) (H3trta = N,N,N-tris-tetrazol-5-yl-amine; H3bta = N,N-bis-tetrazol-5-yl-amine), in which supertrianglar supramolecular building blocks (SBBs) {(Co3F)3(trta)2} act as 12-connected nodes of hexagonal prisms. The unprecedented ligand N,N,N-tris-tetrazol-5-yl-amine is in situ generated via metal-assisted reactions of NaN(CN)2, MeCN, and NaN3, and a possible mechanism involves both 1,3-dipolar cycloaddition and nucleophilic addition. The F-centered Co3 triangles are bridged by trta groups to result in supertriangular {(Co3F)3(trta)2} SBBs that are further arranged in a frustrated triangular lattice. The long-range ordering temperature is reduced to 4.8 K due to strong spin frustration. [ABSTRACT FROM AUTHOR]

A series of Wieland-Miescher ketone analogues bearing highly functionalized substituents are efficiently constructed in high enantioselectivities and good yields using catalytic amounts of prolinamide and PPTS. We have successfully utilized this reaction as a key step to synthesize the tricyclic core of cylindricine type alkaloids. [ABSTRACT FROM AUTHOR]

Hydrothermal in situ [2 + 3] cycloaddition reaction of dicyanamide and azide in the presence of Zn(II) ions at 120, 150, and 180 °C generated [Zn 4O(Hbta) 3(H 2O) 6] 1, [Zn 7(OH) 2(Hbta) 6(H 2O) 6] 2, and [Zn 5(OH) 4(bta) 2]·2H 2O 3(H 3bta = N,N-bis-(1(2)H-tetrazol-5-yl)-amine), respectively. 1crystallizes in hexagonal space group P6̅2 cand shows a layered structure with 3-connected 6 3- hcbtopology in which Zn 3O clusters and unsaturated three-coordinate Zn(II) ions function as 3-connected nodes; 2crystallizes in trigonal space group P3̅ c1 and also shows a layered structure with (3,6)-connected (4 3) 2(4 6)- kgdtopology in which Zn 3O clusters and six-coordinated Zn(II) sites function as 3-connected nodes as 6-connected nodes, respectively; 3is a 3D organic−inorganic hybrid open framework constructed by Zn 5(OH) 4chains. The triply deprotonated bta 3−anion is first observed in 3, and rare three-coordinate Zn(II) ions are revealed in 1. Analysis of relationship between structure and synthesis condition reveals that 1is a metastable kinetic phase whose structure is closely related to that of 2. Both 1and 2are constructed by Zn 3O(Hbta) 3units and discrete Zn ions. The coordination mode of doubly deprotonated Hbta in 1and 2are also same. This study reveals that a higher reaction temperature is helpful to remove amine-hydrogen of H 3bta to form triply deprotonated bta anion. The emergence of triply deprotonated bta species may explain why structure of 3is significantly different from those of 1and 2. Compounds 1−3show strong blue-green emission, assigned as ligand-centered π→π* excitation. [ABSTRACT FROM AUTHOR]

A series of 1-(1-phenyl-1H-tetrazole-5-ylthiol)acetyl-4-aroylthiosemicarbazides were synthesized in good to excellent yields under phase transfer catalytic conditions. By the cyclization of compounds 3a–i in concentrated H 2 SO 4 at 0°C,2-aroylamino-5-(1-phenyl-1H-tetrazole-5-ylthiolmethylene)-1,3,4-thiadiazoles were obtained in high yields. The structures of the products were established by elemental analysis, IR, 1 H NMR, and 13 C NMR. [ABSTRACT FROM AUTHOR]

Seven complexes of metal 4,5-dicarboxyimidazole acid (H3dcbi), namely, [Cd(H2dcbi)2(H2O)3]·H2O (1·α), [Cd(H2dcbi)2-(H2O)2]·2H2O (1·γ), [Cd(H2dcbi)2(H2O)2]·2H2O (1·γ), [Cd(H2dcbi)2(H2O)2] (2), [Cd(Hdcbi)(H2O)] (3), [Cd5(Hdcbi)2-(dcbi)2(H2O)]·XH2O (4), [Cd2(Hdcbi)(C2O4)] (5), [Ag5(Hdcbi)2(CN)] (6), and [Mn(Hdcbi)(H2O)] (7), have been hydro(solvo)thermally synthesized by fine control over synthetic conditions such as stoichiometry, solvent, and pH value. X-ray single-crystal structural analyses reveal that they have rich structural chemistry ranging from mononuclear (1), one-dimensional (2), and two-dimensional (3 and 7) to three-dimensional (4-6), among which 1 crystallizes in three types (α, β, and γ) of polymorphs. Seven coordination modes of Hndcbi ranging from monodentate to μ5 have been observed, among which four modes are found first. The coordination geometries of the Cd(II) sites vary from five-coordinate trigonal bipyramid and square pyramid, six-coordinate octahedron to seven-coordinate pentagonal bipyramid. Analyses of the synthetic conditions and structures of the Cd(ll) complexes show that the influences of the solvent and the metal-to-ligand molar ratio are very important to the products and coordination modes of H2dcbi (n = 0, 1, 2). Studies of the coordination modes of Hndcbi and the structures of the Cd(ll) complexes also reveal that the singly deprotonated H2dcbi generally coordinates in the monodentate imidazole-N or N,O-chelate mode to result in mononuclear structures, the doubly deprotonated Hdcbi coordinates in the μ2, μ3, or μ4 mode to generate one-dimensional or two-dimensional structures, and the triply deprotonated dcbi can coordinate in the μ5 mode to form three-dimensional structures. The cyanide was in situ formed via C-C bond cleavage of acetonitrile during the preparation of 6, which adopts a rare μ4-kC,kC:kN,kN mode to bridge four Ag(l) ions. The microporous three-dimensional framework of 4 is maintained after the removal of the guest molecules. Compounds 1-5 show strong violet emissions with maxima around 380 nm, tentatively attributed to the ligand-centered transition. [ABSTRACT FROM AUTHOR]

Replacement of linear ligand L in CuIXL system (X = halide or pseudohalide; L = 4,4′-bipyridine or pyrazine) by neutral species Cu(pzc)2(H2O)x (pzc = 2-pyrazinecarboxylate) resulted in mixed-valence Cu(I,II) coordination polymers [Cu2(pzc)2Br(H2O)]n (1) and [Cu3(pzc)2(CN)2(H2O)2·2H2O]n (2). Complex 1 has two-dimensional (4,4) topological layer constructed by [CuBr]n chains and Cu(pzc)2(H2O) species, while 2 has a three-dimensional framework formed by linkage of two-dimensional (6,3) layers via ligand-unsupported Cu(I)-Cu(I) interactions. The two-dimensional (6,3) layer in 2 is constructed by zigzag [CuCN]n chains and Cu(pzc)2(H2O)2 species. Cyanides in 2 were produced by oxidative desulfation of SCN- anions. [ABSTRACT FROM AUTHOR]

In this review, some strategies to fabricate starch-based hydrogels are summarized and presented. Hydrophilic hydrogels based on native starch, pure starch components and their derivatives are important due to their swellability in water, biocompatibility and biodegradability. For the preparation of chemically cross-linked starch-based hydrogels, one-step and two-step synthesis by free radical polymerization, cross-linking by chemical reaction of complementary groups and radiation-induced polymerization with the help of gamma or electron beams, are used. For the preparation of physically cross-linked starch-based hydrogels, a novel self-assembly method was used. Some advantages and disadvantages of these synthesis approaches are briefly discussed. [ABSTRACT FROM AUTHOR]

Hydrothermal reactions generated two cuprous cyanide polymorphs with similar hexagonal [Cu2(CN)3] layers but different supramolecular arrays. [ABSTRACT FROM AUTHOR]

The title dinuclear copper complex, [{Cu(C5H15N3)(H2O)}2(C10H8N2)](ClO4)4, has a crystallographically imposed inversion centre. Each CuII atom is coordinated by four N atoms [Cu—N = 2.001 (4)–2.037 (4) Å] and one water mol­ecule [Cu—O = 2.373 (3) Å] in a slightly distorted square-pyramidal geometry. [ABSTRACT FROM AUTHOR]

The cocrystallization of [Cu(SCN)]n chains and [Cu2(4,4′-bpy)CN)2]n (4,4′-bpy = 4,4′-bipyridine) layers generated a 3-D pseudopolyrotaxane compound, [Cu2(4,4′-bpy)(CN)2].[Cu(SON)] (1), which can also be viewed as a 3-D network constructed by linkages of 2-D sheets and I-D chains via unsupported CuI-CuI interactions. The CuI-CuI contact of 2.651(4) Å in 1 is the shortest unsupported CuI-CuI distance documented to date, indicating cuprophilic attractions. [ABSTRACT FROM AUTHOR]

The hydro­thermal reaction of cobalt acetate, vanadium pentoxide and 2,5-bis(4-pyridyl)-1,3,4-thia­diazo­le resulted in the title complex, [Co(V2O6)(C12H8N4S)(H2O)3], in which the cobalt(II) cation shows distorted octahedral geometry, coord­inated by one pyridine N atom, two O atoms from tetravanadate and three water mol­ecules. [ABSTRACT FROM AUTHOR]

A polymer waveguide thermo-optical switch with loss compensation based on NaYF4: 18% Yb3+, 2% Er3+ nanocrystals, fabricated by traditional semiconductor processes, has been investigated. NaYF4: 18% Yb3+, 2% Er3+ nanocrystals were prepared by a pyrolysis method. The morphology and luminescent properties of the nanocrystals were characterized. The nanocrystals were doped into SU-8 as the core material of an optical waveguide amplifier. The size of the device was optimized for its optical and thermal fields as well as its transmission characteristics. The device was fabricated on a silica substrate by spin coating, photolithography, and wet etching. The insertion loss of the switch device is ∼ 15 dB. The rise and fall times of the device are 240 μs and 380 μs, respectively, as measured by application of a 304 Hz square wave voltage. The extinction ratio of the device is about 14 dB at an electrode-driving power of 7 mW. When the pump light power is 230 mW and the signal light power is 0.1 mW, the loss compensation of the device is 3.8 dB at a wavelength of 1530 nm. Optical devices with loss compensation have important research significance. [ABSTRACT FROM AUTHOR]

The article presents a study that investigates the performance field-effect transistors (FET) after solution casting of benzothiadiazole and cyclopentadithiophene copolymer. The authors have presented a benzothiadiazole and cyclopentadithiophene alternating copolymers which exhibited ability to self-assemble into a lamellar superstructure. They also noted that the study provided functionally desirable FET performance characteristics with mobilities up to 0.17 cm. when solution was deposited.

Uniform polymeric nanospheres comprised of hydrophilic cores and hydrophobic coronas were prepared by dispersion free radical copolymerization of acrylamide with poly(tert-butyl methacrylate) macromonomer (PtBMA) in ethanol/water mixed solvents, and the effects of cross-linker addition on the nanosphere size were investigated. Chemical analysis by electron spectroscopy confirmed that hydrophobic PtBMA chains grafted to the nanosphere surfaces. Changes in concentrations of the monomers and the cross-linker controlled the hydrodynamic diameter of the nanospheres (140-540 nm). [ABSTRACT FROM AUTHOR]

In the title compound, [Co(C9H8NO4)2(H2O)4]·4H2O, the Co atom lies on an inversion centre in an octahedral environment that is formed from two O atoms of two 2,6-dimethylpyridinium-3,5-dicarboxylate monoanions and four water molecules. Hydrogen bonds that involve the pyridinium NH groups and both coordinated and uncoordinated water molecules give rise to an infinite three-dimensional network. [ABSTRACT FROM AUTHOR]

The reaction of hexane-1,6-diamine with sodium molybdate and phospho­ric acid yields the title salt, (C6H18N2)2[Mo5(HPO4)2O15]·2H2O. Two penta­molybdate anions are linked by hydrogen bonds to form a dimer; the dimers are incorporated into the network structure through hydrogen bonds involving the hexane-1,6-diaminium cations and uncoordinated water mol­ecules. [ABSTRACT FROM AUTHOR]

The article presents an estimation of C(sub4)-H bond dissociation energies of nicotinamide adenine dinucleotide (NADH) and its radical cation in aqueous solution. It is ubiquitous and controls so much of the oxidation and reduction nature, that there has been a long-standing interest in the mechanisms of the redox interconversions. Chemists have given considerable attention to the chemistry of NADH and its models. An interesting controversy is whether the formal hydride transfer from NADH to the surrounding substrates occurs in a one-step or multistep sequence involving electron transfer as the initial step.

Seven cupric halide coordination polymers, namely [Cu5(OH)3Br3(ina)4] (1), [Cu5(OH)3Cl3(ina)4] (2), [Cu2(OH)Cl(ina)2] (3), [Cu3(OH)2Cl2(ina)2]·2H2O (4), [Cu3(OH)2Br2(ina)2]·2H2O (5), [Cu2Cl2(ina)2(H2O)2] (6), [Cu2Cl(ina)2(gca)(H2O)] (7), cupric complex templated cuprous halide [CuII(Me-ina)2(H2O)][Cu5IBr7] (8), and organic templated cuprous halide Me2-ina[Cu2Br3] (9) (Hina = isonicotinic acid), were prepared from the starting materials of cupric halide and Hina via fine-tuning solvothermal reactions. According to valence states of copper, 1-7 are copper(II) complexes, 8 is a mixed-valent Cu(I,II) complex, while 9 is a Cu(I) compound. According to bonding types of halides, nine complexes can be classified as three types: complexes 1-3 include only normal X-Cu bond (X = halide); complexes 4-7 include normal X-Cu bond and X···Cu weak bond; complexes 8 and 9 include normal X-Cu bond and X···H-C halogen hydrogen bonds. Complexes 1 and 2 are isomorphic three-dimensional (3D) pcu topological metal organic frameworks (MOFs) with butterfly-like Cu4(μ3-OH)2X2 and steplike Cu6(μ3-OH)4 cores as nodes, showing strong ferromagnetic couplings. Complex 3 also is a pcu topological MOF with only butterfly-like Cu4(μ3-OH)2Cl2 clusters as nodes, presenting spin canting antiferromagnetic behavior. Isostructural 4 and 5 are Cu3(OH)2 clusters based two-dimensional (2D) (4,4) layers, which are extended into 3D eight-connected networks via weak Cu···X bonds, showing ferromagnetic coupling. Antiferromagnetic 6 is a simple one-dimensional coordination polymer, which is extended via weak Cu···Cl bonds into 3D (3,4)-connected networks. Paramagnetic 7 is a ladderlike polymer, which is extended into 2D (3,4)-connected layer via weak Cu···Cl bonds. The syntheses of polymeric cupric complexes 1-7 mainly result from differences in reactant ratio and pH value. Utilization of reducing methanol generated novel cubane-containing [Cu5Br7]2- chain templated by paddlewheel-like [CuII(Me-ina)2]2+ 8 and face-shared dimer-containing [Cu2Br3]- chain templated by N-methylated and O-esterificated Me2-ina 9. Complex 9 exhibits a strong red emission and a weaker green emission upon excitation. [ABSTRACT FROM AUTHOR]

By using environmental friendly K3[Fe(CN)6] as a cyanide source, hydrothermal reactions of CuCl2and diamines resulted in four Cu2(1,1,2-μ3-CN)2(CN)4dimer-based organic templated cuprous cyanide open frameworks, namely, [H1.5mepip]2[Cu4(CN)7] (1), [H1.5etpip]2[Cu4(CN)7] (2), [H2me2pip][Cu3(CN)5] (3), and [H2dmpa][Cu4(CN)6] (4) (mepip = N-methylpiperazine; etpip = N-ethylpiperazine, me2pip = N,N-dimethylpiperazine, dmpa = 3-dimethyl-aminopropylamine). Isomorphic 1and 2show three-dimensional (3-D) (4,6)-connected FeS2-like open frameworks constructed by 4-connected Cu(CN)4monomers and 6-connected Cu2(CN)6dimers. Complex 3shows an unprecedented 3-D (4,6)-connected open framework in which the ratio of 4-connected Cu(CN)4monomers to 6-connected Cu2(CN)6dimers is 1:1. Complex 4shows a 3-D (3,6)-connected AgIn2-like open framework constructed by 3-connected Cu(CN)3monomers and 6-connected Cu2(CN)6dimers. Different from CuCN/amine coordination polymers, the protonated organic diamines in 1–4act as templates in the formation of cuprous cyanide open frameworks. Even at ambient temperature, 1, 2, 3, and 4show strong blue-green photoluminescence related to Cu2(CN)6dimer, which is mainly assigned to metal-to-ligand charge-transfer (MLCT) by time-dependent density functional theory (TD-DFT) and electronic band structure calculations. [ABSTRACT FROM AUTHOR]

MEKK3 serves as a critical intermediate signaling molecule in lysophosphatidic acid-mediated nuclear factor-κB (NF-κB) activation. However, the precise regulation for MEKK3 activation at the molecular level is still not fully understood. Here we report the identification of two regulatory phosphorylation sites at Thr-516 and Ser-520 within the kinase activation loop that is essential for MEKK3-mediated IκB kinase β (IKKβ)/NF-κB activation. Substitution of these two residues with alanine abolished the ability of MEKK3 to activate IKKβ/NF-κB, whereas replacement with acidic residues rendered MEKK3 constitutively active. Furthermore, substitution of these two residues with alanine abolished the ability of MEKK3 to mediate lysophosphatidic acid-induced optimal IKKβ/NF-κB activation. [ABSTRACT FROM AUTHOR]

The reaction of [Mn12(CH3COO)16(H2O)4O12] · 2CH3COOH · 4H2O, Na8[HPW9O34] · 24H2O, K2HPO4, and ethylenediamine hydrochloride in an aqueous solution leads to the isolation of a new polyoxometalate-based mixed-valent manganese aggregate, K14Na17[(MnIII13MnIIO12(PO4)4(PW9O34)4)· ~56H2O (1). Single-crystal X-ray diffraction indicates that the polyoxoanion of 1 exhibits a mixed-valent [MnIII13MnII(μ2-O)6(μ3-O)6(μ4-PO4)2(μ5-PO4)2]5+ complex encapsulated by four [B-α-PW9O34]9- trivacant Keggin-type moieties [crystal data for 1: monoclinic, C2/c (No. 15), a = 36.341(7) Å, b = 18.325(4) Å, c = 36.668(7) Å, β = 119.24(3)°, V = 21308(7) Å3 Z = 4]. In a magnetic point of view, all of these paramagnetic manganese aggregates in 1 are well wrapped into the diamagnetic inorganic shells. Variable-temperature, solid-state, direct-current susceptibility measurements show that compound 1 exhibits strong antiferromagnetic interactions inside the [Mn14] core. [ABSTRACT FROM AUTHOR]

The structure and stability of a set of (CF)60 isomers have been computed at the B3LYP/6-31G-(d) density functional theory level. The most stable isomer (6, F4@C60F56) has tube-like structure with four endo C-F bonds and fused five-membered rings at the end of the tube, while the reported most stable cage structure (2, F8@C60F52) with eight endo C-F bonds is higher in energy by 22.6 kcal/mol. This is in contrast to the isolated pentagon rule for the stability of fullerenes. The mean bond dissociation energy of 6 is larger than those of the experimental known C60F36, C60F48, and graphite fluoride. The relative energy per CF unit of 6 to graphite fluoride (CF)n is 3.7 kcal/mol, which is smaller than that of C60 fullerene per carbon to graphite (about 9-10 kcal/mol). [ABSTRACT FROM AUTHOR]