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Jörg Schönherr - One of the best experts on this subject based on the ideXlab platform.

  • Die postinfektionellen Wirkungen von Kupferhydroxid und Kupfersulfat auf Konidien von Venturia inaequalis
    2020
    Co-Authors: Jurith Montag, Lukas Schreiber, Jörg Schönherr
    Abstract:

    The post-infection activity of Copper Hydroxide and Copper sulfate against conidia of Venturia inaequalis were evaluated using an in vitro test system based on isolated apple leaf cuticles. Experiments were conducted at 20°C and treatments were applied 24 or 48 h after inoculation. Experiments were assessed by counting living primary stromata 72 h after inoculation using fluorescence microscopy and fluorescein diacetate (FDA) as a vital stain. Copper Hydroxide and Copper sulfate showed post-infection activity and killed primary stromata, provided the surface of the CM was kept wet. Copper Hydroxide was more effective than Copper sulfate and was able to kill all primary stromata 24 h after inoculation at concentrations of 116 and 231 mg l-1. Results indicate different modes of action for the highly water soluble Copper sulfate and the slightly soluble Copper Hydroxide. Application of Copper Hydroxide to dry CM did not kill primary stromata. Hence, for Copper Hydroxide to exert post-infection activity leaves must be wet.

  • An In Vitro Study of the Nature of Protective Activities of Copper Sulphate, Copper Hydroxide and Copper Oxide Against Conidia of Venturia inaequalis
    Journal of Phytopathology, 2006
    Co-Authors: Jurith Montag, Lukas Schreiber, Jörg Schönherr
    Abstract:

    Copper is one of the oldest fungicidal agents, yet little is known about its mode of action. Solubilities of Copper fungicides currently in use range from nil (Copper oxide) to high (Copper sulphate). We have investigated the effect of water solubility on protective activities of Copper sulphate, Copper Hydroxide (slightly soluble) and Copper oxide using conidia of Venturia inaequalis and an in vitro test system based on isolated apple leaf cuticles. Effects were assessed microscopically using two vital stains; fluorescein diacetate (FDA) indicates esterase activity and integrity of the spore membrane, and cyanoditolyl tetrazolium chloride (CTC) was included to test the integrity of the mitochondrial respiration chain. Solutions (Copper sulphate) or suspensions (Copper oxide, Copper Hydroxide) at concentrations of 1, 10 or 25 mmol/l was applied to the surfaces of cuticles 24 h before inoculation and allowed to dry. Conidia applied to these residues failed to germinate at all treatment concentrations. With Copper Hydroxide and Copper oxide some ungerminated conidia exhibited some residual fluorescence when stained with FDA, especially at low concentrations. At all concentrations tested, ungerminated spores did not fluoresce when stained with CTC. This is the first evidence that Copper fungicides kill scab spores by inhibiting mitochondrial respiration. A filtrate prepared from Copper oxide suspension was completely ineffective, while a filtrate from Copper Hydroxide suspension slightly inhibited spore germination and prevented the formation of appressoria. The results indicate that the fungicidal action of the slightly and insoluble Copper Hydroxide and Copper oxide, respectively, cannot be explained based on the concentration of dissolved Copper ions. It is likely that solubilization of Copper from solid residues was assisted by direct contact between spore membranes, exudates and the solid Copper containing particles. The generation of reactive oxygen species (ROS) in suspensions of Copper Hydroxide and Copper oxide could not be detected using chemiluminescence analysis. Hence ROS were not formed on the surfaces of Copper containing particles and could not be involved in Copper toxicity.

  • An in vitro study on the postinfection activities of Copper Hydroxide and Copper sulfate against conidia of Venturia inaequalis.
    Journal of Agricultural and Food Chemistry, 2006
    Co-Authors: Jurith Montag, Lukas Schreiber, Jörg Schönherr
    Abstract:

    The postinfection activities of Copper Hydroxide [Cu(OH)2] and Copper sulfate (CuSO4) against apple scab (Venturia inaequalis) were evaluated in an in vitro study. Our intention was to support the aim of reducing Copper application rates by appropriate timing of applications. Experiments were conducted at 20 °C with leaf disks and isolated cuticular membranes (CM) of Malus × domestica ‘Gloster' and ‘Elstar'. Conidia of V. inaequalis were used as the inoculum. In untreated controls, 7.9 and 33.2% of germinated conidia formed primary stromata 24 and 48 h after inoculation, respectively. Treatments with Copper compounds were applied 24 and 48 h after inoculation, which was 16 and 40 h after infection had occurred. When working with CM and using fluorescein diacetate as a vital stain, vital and dead stromata could be distinguished. Treatment effects were assessed 72 h after inoculation by counting vital (fluorescing) primary stromata. With leaf disks, the number of stromata was counted using KOH−aniline blue ...

Wataru Fujita - One of the best experts on this subject based on the ideXlab platform.

  • Crystal growth, structures and magnetic properties of Copper Hydroxide compounds with distorted diamond chain magnetic networks
    CrystEngComm, 2016
    Co-Authors: Wataru Fujita, Akio Tokumitu, Yutaka Fujii, Hikomitsu Kikuchi
    Abstract:

    Single crystals of Copper Hydroxide compounds (1–7) containing organic sulfonate ions (ethane-1,2-disulfonate, 1-octanesulfonate, p-toluenesulfonate, p-ethylbenzenesulfonate, 2-naphthalenesulfonate, 1,5-naphthalenedisulfonate, and 2,6-naphthalenedisulfonate, respectively) were easily prepared by the hydrolysis of Copper acetate aqueous solution containing the respective organic sulfonates. All seven compounds had distorted diamond chain magnetic networks similar to that found in azurite (Cu3(CO3)2(OH)2). The diamond chain units were composed of Copper, Hydroxide, and acetate ions and water molecules (with additional sulfonate ions in the case of 7). The anions or molecules bridged the neighbouring Copper ions, and might mediate superexchange interactions between Copper atoms. The chain units did not have the same structure, and were slightly different in their Cu–O bond lengths, Cu–O–Cu bridging angles and so on. Magnetic measurements revealed primarily antiferromagnetic interactions between the neighbouring Copper ions and no antiferromagnetic ordering. The χpvs. T plots showed broad maxima at around 60–80 K that are characteristic of low-dimensional magnetic networks. Compounds 1–6 were paramagnetic down to 2 K, while 7 had a diamagnetic ground state. The different magnetic properties are due to the small structural differences in the diamond chain units, because the sign and intensity of magnetic coupling between the neighbouring Copper ions are sensitive to the bridging structures. Copper Hydroxide compounds with different organic ions and diverse structures prepared by this hydrolysis method will facilitate the systematic study of the underlying diamond chain magnetic networks.

  • Convenient crystal growth, structural determination and magnetic studies of layered Copper Hydroxides containing aromatic sulfonates
    CrystEngComm, 2015
    Co-Authors: Wataru Fujita
    Abstract:

    Single crystals of layered Copper Hydroxides, 1–4, with aromatic sulfonate ions, p-toluenesulfonate, p-ethylbenzenesulfonate, 1-naphthalenesulfonate and 1,5-naphthalenedisulfonate, respectively, were conveniently prepared by hydrolysis of aqueous Copper acetate solutions containing the organic sulfonates. X-ray structure analyses revealed that these compounds had alternating stacks of Copper Hydroxide layers and aggregated layers of the organic ions. The atomic alignment of their Copper Hydroxide layers was similar to that of the inorganic layer of hydrotalcite, [Mg6Al2(OH)16]·CO3·16H2O. However, their Copper Hydroxide layers were not isostructural among 1–4. In the Copper Hydroxide layers, not only Hydroxide ions but also water molecules, acetate ions or the organic sulfonate ions were coordinated to the Copper ions. The Copper ions exhibited an elongated octahedral geometry in 1 and 2, and an elongated octahedral or square pyramidal geometry in 3 and 4. The organic ions formed a bilayer arrangement in 1 and 2, and a monolayer arrangement in 3 and 4. Magnetic measurements revealed primarily antiferromagnetic interactions between neighbouring Copper ions. The magnetic behaviours of these materials resembled the antiferromagnetic ordering behaviour at low temperatures. The maximum values of χp were observed at 3.8 K, 3.5 K, 3.2 K and 9.1 K for 1–4, respectively. The exchange coupling constants were estimated from an S = 1/2 Heisenberg model with a two-dimensional triangular lattice magnetic network, where J/kB = 42.2 K, 36.8 K, 80.1 K and 84.9 K for 1–4, respectively. The magnetic differences in these materials are due to the structural differences in their Copper Hydroxide layers. Thus, it was demonstrated that hydrolysis methods are suitable for the preparation of single crystals of various Copper Hydroxide derivatives with organic anions.

  • New Layered Copper Hydroxide with S = 1/2 Two-Dimensional Triangular Lattice Magnetic Network, [Cu7(OH)12(CH3CH2CO2)2]·(CH3CH2CO2H)2·(H2O)6
    Bulletin of the Chemical Society of Japan, 2013
    Co-Authors: Wataru Fujita, Koichi Kikuchi
    Abstract:

    We have succeeded in preparing single crystals of the layered Copper Hydroxide [Cu7(OH)12(CH3CH2CO2)2]·(CH3CH2CO2H)2·(H2O)6 (1) through hydrolysis of a Copper propionate solution. X-ray structure a...

  • new layered Copper Hydroxide with s 1 2 two dimensional triangular lattice magnetic network cu7 oh 12 ch3ch2co2 2 ch3ch2co2h 2 h2o 6
    Bulletin of the Chemical Society of Japan, 2013
    Co-Authors: Wataru Fujita, Koichi Kikuchi
    Abstract:

    We have succeeded in preparing single crystals of the layered Copper Hydroxide [Cu7(OH)12(CH3CH2CO2)2]·(CH3CH2CO2H)2·(H2O)6 (1) through hydrolysis of a Copper propionate solution. X-ray structure a...

Xinsheng Peng - One of the best experts on this subject based on the ideXlab platform.

  • room temperature synthesis of free standing hkust 1 membranes from Copper Hydroxide nanostrands for gas separation
    Chemical Communications, 2013
    Co-Authors: Hubiao Huang, Junwei Li, Xinsheng Peng
    Abstract:

    Large scale, robust, well intergrown free-standing HKUST-1 membranes were converted from Copper Hydroxide nanostrand free-standing films in 1,3,5-benzenetricarboxylic acid water–ethanol solution at room temperature, and explored for gas separation. The truncated crystals are controllable and favorable for the dense intergrowth.

  • mesoporous separation membranes of polymer coated Copper Hydroxide nanostrands
    Advanced Functional Materials, 2007
    Co-Authors: Xinsheng Peng, Izumi Ichinose
    Abstract:

    Extremely long and thin nanocomposite fibers are prepared by oxidative polymerization of pyrrole (or aniline) around the surfaces of Copper Hydroxide nanostrands. The individual nanostrands of 2.5 nm are uniformly coated with a polypyrrole layer of 3 to 4 nm, resulting in hybrid core/shell fibers of about 10 nm in diameter and a few micrometers in length, as confirmed by high-resolution electron microscopy. The as-prepared nanocomposite fibers are dispersive in water and can be converted into thin free-standing films by simply filtering a small volume of the aqueous solution using a polycarbonate membrane filter. The films covering the submicrometer pores of the membrane filter have a thickness of a few tens of nanometers, and provide a mechanically stable nanofiber network with abundant pores of a few nanometers. The network is stable in acidic and basic media, and can be used for protein separation under pressures of at least 90 kPa. The permeation rates of cytochrome c, myoglobin, and ferritin were examined by changing the pH around their isoelectric points. It is seen that the nanofibrous free-standing films on the polycarbonate membrane filter show clear size selectivity for the proteins, retaining extremely high filtration rates for water. We demonstrate herein durable mesoporous separation membranes made of organic–inorganic nanocomposite fibers and their outstanding performance.

  • formation of positively charged Copper Hydroxide nanostrands and their structural characterization
    Chemistry of Materials, 2006
    Co-Authors: Jianguo Huang, Xinsheng Peng, Wolfgang Schmitt, Izumi Ichinose
    Abstract:

    Extremely narrow Copper Hydroxide nanostrands with a diameter of 2.5 nm were prepared by controlling the pH of an aqueous Copper nitrate solution with weak bases. The nanostrands grew slowly from initially formed small particles of 2−6 nm. The growth was highly sensitive to the amount and types of weak bases. Long nanostrands were obtained in a range of pH 6.0−6.2 at a concentration of approximate 2 mM Copper nitrate. The length reached several tens of micrometers after an aging time of a few days, giving an aspect ratio more than tens of thousands. Their structures were characterized by scanning electron microscopy, transmission electron microscopy (TEM), and electron diffraction. This nanostrand is composed of positively charged linear clusters, [Cu8(OH)14(H2O)4]2+, as judged from the results of high-resolution TEM, UV−vis titration experiments, and crystallographic considerations. We widely investigated the nanomorphologies of Copper Hydroxide and related compounds by changing the synthetic conditions ...

Seonghun Park - One of the best experts on this subject based on the ideXlab platform.

  • Confined condensation synthesis and magnetic properties of layered Copper Hydroxide frameworks
    Dalton Transactions, 2017
    Co-Authors: Seonghun Park, Myung-hwa Jung
    Abstract:

    We present a confined condensation technique for the fabrication of layered Copper Hydroxide frameworks from lamellar Copper-organic assemblies with long alkyl chains through the selective introduction of hydroxo bridging ligands. The complete transformations of two different lamellar Copper-organic assemblies, Cu(C12H25SO4)2·4H2O (Cu-DS) and Cu2(C11H23CO2)4·2H2O (Cu-lau), into the corresponding layered Copper Hydroxide frameworks, Cu2(OH)3(C12H25SO4) (Cu-OH-DS) and Cu2(OH)1.8(C11H23CO2)2.2 (Cu-OH-lau), were achieved via confined condensation. The magnetic properties of both lamellar Copper-organic assemblies, Cu-DS and Cu-lau, and both layered Copper Hydroxide frameworks, Cu-OH-DS and Cu-OH-lau, were investigated. It was found that drastic changes in the magnetic properties arise as a result of the confined condensation process.

  • Synthesis, characterization and magnetic properties of a novel disulfonate-pillared Copper Hydroxide Cu2(OH)3(DS4)1/2, DS4 = 1,4-butanedisulfonate
    Bulletin of The Korean Chemical Society, 2006
    Co-Authors: Seonghun Park
    Abstract:

    We report the preparation, structure and magnetic properties of a new pillared complex, Copper(II) hydroxy-1,4-butanedisulfonate, . The titled compound was obtained by anion exchange, using Copper hydroxyl nitrate as the starting material. According to the XRD data, this compound exhibits a pillared layered structure with organic layers tilted between the Copper Hydroxide layers with a tilt angle of . FTIR spectroscopy confirms total exchange of nitrate by the sulfonate and indicates that the sulfonate functions are linked to the Copper(II) ions with each aliphatic chain bridging the adjacent Hydroxide layers. According to the dc and ac magnetic measurements, the title compound is a metamagnet consisting of spin-canted antiferromagnetic layers, with a Neel temperature of 11.8 K.

  • Layered Copper Hydroxide n-Alkylsulfonate Salts: Synthesis, Characterization, and Magnetic Behaviors in Relation to the Basal Spacing
    Journal of Physical Chemistry B, 2005
    Co-Authors: Seonghun Park
    Abstract:

    A series of hybrid inorganic−organic Copper(II) hydroxy n-alkylsulfonate with a triangular lattice, Cu2(OH)3(CnH2n+1SO3) (n = 6, 8, 10), are prepared by anion exchange, starting from Copper hydroxy nitrate Cu2(OH)3NO3. These compounds show a layered structure as determined by X-ray diffraction, with interlayer distances of 14.3−34.8 A in alternation with interdigitated bilayer packing. Magnetic properties have been investigated by means of dc and ac measurements. All the compounds show similar metamagnet behaviors, with a Neel temperature of about 11 K. A subtle difference in the ac magnetic susceptibility among the compounds is understood by the existence of hydrogen bonding between the sulfonate headgroup and the Hydroxide anion. A detailed molecular structure of the alkyl chains incorporated to the inorganic Copper Hydroxide layer is also discussed from the FTIR data.

  • unidirectionally aligned Copper Hydroxide crystalline nanorods from two dimensional Copper hydroxy nitrate
    Journal of the American Chemical Society, 2004
    Co-Authors: Seonghun Park
    Abstract:

    We were able to synthesize unidirectionally aligned Copper Hydroxide nanorods from two-dimensional Copper Hydroxide nitrate by anion exchange reaction using NaOH without any membrane or template. The structural conversion from Cu2(OH)3NO3 to Cu(OH)2 was confirmed by XRD and FT-IR data. The synthesized Copper Hydroxide nanorods showed unidirectionally aligned and tightly bound arrays on a hexagonal plate, leading to giant nanorod bundles.

Koichi Kikuchi - One of the best experts on this subject based on the ideXlab platform.