Synthesis and Crystal Structure of the Hydrated Nickel(II) Complex of Tartrate

Abstract  A new dinuclear hydrated nickel(II) tartrate has been isolated and structurally characterized by single-crystal X-ray diffraction. The title compound formulated as [Ni₄(C₄H₄O₆)₄(H₂O)₈](EtOH)_0.5(H₂O)_10.25 (C₁₇H_55.5Ni₄O_42.75) crystallizes in monoclinic system, space group P2(1)/c with a = 13.684(5), b = 17.143(6), c = 18.586(6) ?, β = 96.638(6)°, V = 4331(3) ?³, Z = 4. The unit cell contains two crystallographic independent dimeric units of [Ni₂(C₄H₄O₆)₂(H₂O)₄] without significant structural difference, half of menthol molecule and ten and a quarter packing water molecules. In each dimeric unit, one (R,R)-tartrato dianion chelates two Ni(II) ions by the use of two hydroxy oxygen and two carboxyl oxygen atoms as donor atoms, and another tartrato dianion chelates the same pair of Ni(II) cations in the same way. Each Ni(II) atom is six-coordinated by six O atoms from two tartrate units and two water molecules. Index Abstract  The crystal structure of complex [Ni₄(C₄H₄O₆)₄(H₂O)₈](EtOH)_0.5(H₂O)_10.25 contains two crystallographic independent dimeric units of [Ni₂(C₄H₄O₆)₂(H₂O)₄] without significant structural difference. In each dimeric unit, one (R,R)-tartrato dianion chelates two Ni(II) ions by the use of two hydroxy oxygen and two carboxyl oxygen atoms as donor atoms, and another tartrato dianion chelates the same pair of Ni(II) cations in the same way.      

Peak shape analysis of Ag 3d core‐level X‐ray photoelectron spectra of Au@Ag core‐shell nanoparticles using an asymmetric Gaussian–Lorentzian mixed function

This article reports on the peak shape analysis of X‐ray photoelectron spectra of gold‐silver core‐shell (Au@Ag) nanoparticles (NPs) using an asymmetric Gaussian–Lorentzian mixed function. Unlike Ag NPs, Au@Ag NPs have no oxide peak and show asymmetric line shape with a high energy tail in Ag 3d core‐level spectra. A monotonic increase in the Ag 3d binding energy and a decrease in the degree of asymmetry with increasing the Ag shell thickness were observed supporting the occurrence of charge transfer from Au core to Ag shell. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis of 4″-benzyloxyimino-4″-deoxyavermectin Bla derivatives

Six new 4″-benzyloxyimino-4″-deoxyavermectin Bla derivatives were synthesized from avermectin Bla by the selective protection of C-5-hydroxy group,oxidation of C-4″-hydroxy group,and deprotection followed by reaction with O-substituted hydroxylamine hydrochlorides.Their structures were confirmed by IR,~1H NMR,~(13)C NMR and MS.Insecticidal activities of the derivatives against Phopalosiphum pseudobrassicae,Spodoptera exigua and Pluteua xylosteua were evaluated.     

A new approach to the synthesis of α-chlorocycloalkanones

α-Chlorocycloalkanones(Ⅳ) were synthesized from cycloalkanones via potassiumα-oxocycloalkylsulfonates(Ⅱ).A two-step mechanism was proposed to explain the formation ofⅣfromⅡ.     

Novel Copolymers of Styrene. 12. Halogen Ring-Substituted Methyl 2-Cyano-3-Phenyl-2-Propenoates

Electrophilic trisubstituted ethylenes, halogen ring-substituted methyl 2-cyano-3-phenyl-2-propenoates, RPhCH=C(CN)CO₂CH₃ (where R is 3-Br-4-CH₃O, 5-Br-2-CH₃O, 2-F-5-CH₃, 2-F-6-CH₃, 4-F-3-CH₃, 4-F-3-PhO, 2-F-5-I, 2-F-6-I, 2-F₃C, 4-F₃C) were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and methyl cyanoacetate, and characterized by CHN analysis, IR, ¹H and ¹³C-NMR. All the ethylenes were copolymerized with styrene (M₁) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, ¹H and ¹³C-NMR. The order of relative reactivity (1/r ₁) for the monomers is 2-F-5-CH₃ (6.4) > 4-F-3-PhO (5.6) > 4-F₃C (4.8) > 3-Br-4-CH₃O (3.7) > 2-F-5-I (3.6) > 2-F₃C (2.2) > 2-F-6-I (2.1) > 5-Br-2-CH₃O (1.9) > 4-F-3-CH₃ (1.8) > 2-F-6-CH₃ (1.2). Relatively high T _g of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200-500°C range with residue (2–21% wt), which then decomposed in the 500–800°C range.     

Synthesis, structures and membrane properties of siloxane-imide co-polymers produced by aqueous polymerization

We report for the first time, the synthesis of siloxane-imide co-polymers by the reaction of mixtures of 1,4-bis(aminobutyl)tetramethyldisiloxane (ABTMDS) and 1,3-bis(4-aminophenoxy)benzene (TPE-R) with bisphenol A diphthalic anhydride (BPADA) using water as the polymerization solvent. A series of co-polymers were prepared incorporating 10, 20, 40 and 100 mol% of ABTMDS with the aromatic diamine TPE-R as the co-monomer. The synthesized co-polymers showed number average molecular weights in the range of 25,000–60,000. As expected the glass transition temperatures (T_gs) and moduli of the polymers were found to decrease with increasing amounts of the siloxane monomer and the homo-polymer containing only the siloxane diamine showing the lowest T_g (60 °C). The resulting polymers could be solution cast into strong and flexible membranes which showed significant decreases in water absorption and moisture permeability compared to the control polymer without siloxane groups. The polymers were characterized by FTIR, ¹³C and ¹H NMR, GPC, DSC and mechanical properties and structural comparisons were made with similar polymers made by standard solvent synthesis methods. Also cross-linked polymers were prepared by the reaction of ABTMDS with the aromatic homo-polymer control and their membrane properties were compared to those of the water synthesized siloxane co-polymers with a similar siloxane content.     

Dimeric hexakis(4‐methyl­benzoato)­bis(1,10‐phenanthroline)didyspros­ium(III)

The title compound, [Dy₂(C₈H₇O₂)₆(C₁₂H₈N₂)₂], forms binuclear complexes, viz. di‐μ‐4‐methyl­benzoato‐κ⁴O:O′‐bis[bis(4‐methyl­benzoato‐κ²O,O′)(1,10‐phenanthroline‐κ²N,N′)dyspros­ium(III)] tetra‐μ‐4‐methyl­benzoato‐κ⁸O:O′‐bis[(4‐methyl­benzoato‐κ²O,O′)(1,10‐phenanthroline‐κ²N,N′)dyspros­ium(III)]. There are two independent binuclear com­plexes in the asymmetric unit, both of which are centrosymmetric. In one, the Dy^III ions are linked by two bridging 4‐­methyl­benzoate groups, while in the other, the Dy^III ions are linked by four bridging 4‐methyl­benzoate groups. The remaining 4‐methyl­benzoate groups and 1,10‐phenanthroline units coordinate to just one metal ion in bidentate modes.     

Reactions of [60]Fullerene with Di(azidomethyl) benzenes

Alargenumberofadditionsto[6O]fullerenehavebeeninvestigated.However,mostoftheworkhaveconcentratedontheformationofthemono-additionproductS0f[60]fullerene'-Thedevelopment0fselechveroutestomultipleadductShascurrentlybecomethefrontierinthechendstryof[60]fuIlerene'~'.FollowingtheaPplicahonoftether-directedremotefunctionalizati0ntotheregi0specificformati0nofthedi-andtriadductSof[60]fullerene,F.Diederichetal6alsodescribed'awayforthedirectdifunctionalizationof[60]fullerenebasedonacyclizationreachono…     

Synthesis and biological evaluation of a lipopeptide-based methamphetamine vaccine

We describe an application of carrier protein-free strategy in constructing a fully synthetic methamphetamine (METH) vaccine that contains three components: Toll-like receptor 2 ligand, Th2 epitope, and METH hapten. The immunological evaluation in mice revealed high titers of METH-specific antibodies induced by the construct and the activation of humoral immunity that would be beneficial for neutralization and clearance of the METH molecule. Behavioral experiments indicated that the synthetic vaccine attenuated the acquisition of METH-induced conditioned place preference and inhibited the initiation and expression of METH-induced locomotor sensitization. These results demonstrate that the lipopeptide-based vaccine has invoked an immune response and showed the potential of preventing the rewarding and psychoactive effects of METH.