The Effect of Water upon Deep Eutectic Solvent Nanostructure: An Unusual Transition from Ionic Mixture to Aqueous Solution

The nanostructure of a series of choline chloride/urea/water deep eutectic solvent mixtures was characterized across a wide hydration range by neutron total scattering and empirical potential structure refinement (EPSR). As the structure is significantly altered, even at low hydration levels, reporting the DES water content is important. However, the DES nanostructure is retained to a remarkably high level of water (ca. 42 wt % H₂O) because of solvophobic sequestration of water into nanostructured domains around cholinium cations. At 51 wt %/83 mol % H₂O, this segregation becomes unfavorable, and the DES structure is disrupted; instead, water–water and DES–water interactions dominate. At and above this hydration level, the DES–water mixture is best described as an aqueous solution of DES components.     

Effect of solvent extraction on the atomic-absorption spectrophotometric determination of traces of copper with zinc dibenzyldithiocarbamate

Summary The utility of various organic solvents, such as acetates and ketones, for the CuDBC chelate extraction and subsequent atomic absorption spectrophotometric determination is studied. Methyl propionate was found to be the most sensitive solvent. Data for the different substances are presented.

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Einfluß der Lösungsmittelextraktion auf die AAS-Bestimmung von Kupferspuren mit Zinkdibenzyldithiocarbamat

Zusammenfassung Die Verwendbarkeit verschiedener Lösungsmittel (Acetate und Ketone) für die Extraktion des CuDBC-Komplexes und anschließende atomabsorptions-spektralphotometrische Bestimmung wurde systematisch untersucht. Werte für die verschiedenen Substanzen werden angegeben. Die größte Empfindlichkeit kann mit Methylpropionat erzielt werden.

We wish to thank President Dr. Yawara Yoshitoshi and Prof. Dr. Nobuo Sakurai of Hamamatsu University School of Medicine, for their hospitality and encouragement.     

Isolation of the intermetallic compounds Al2Cu, Al12Mg17 Al3Fe, Al9Co2 and Al3Ni in binary aluminium alloys by application of an organic solvent

Summary For the isolation of the intermetallic compounds Al₂Cu, Al₁₂Mg₁₇, Al₃Fe, Al₉Co₂ and Al₃Ni in their binary alloys a new method is proposed: Sample alloy particles are placed in a flask with a methanolic solution of benzoic acid (20% wt.), oxine (5% wt.), chloroform (20% vol.) and sodium hydroxide (0.02% wt.). After sufficient time of agitation, the intermetallic compounds remain quantitatively in the solution.

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Isolierung der intermetallischen Verbindungen Al₂Cu, Al₁₂Mg₁₇, Al₃Fe, Al₉Co₂ und Al₃Ni aus binären Aluminiumlegierungen mit Hilfe eines organischen Lösungsmittels

Zusammenfassung Zur Isolierung der intermetallischen Verbindungen aus den entsprechenden binären Legierungen wird die Probe mehrere Stunden bis Tage unter Rühren mit einer methanolischen Lösung von Benzoesäure (20%), Oxin (5%), Chloroform (20%) und Natriumhydroxid (0,02%) behandelt. Hierbei wird die Matrix aufgelöst und die intermetallischen Verbindungen bleiben zurück.

     

An Intrinsically Non-flammable Electrolyte for High-Performance Potassium Batteries

Potassium-ion batteries are promising for low-cost and large-scale energy storage applications, but the major obstacle to their application is the lack of safe and effective electrolytes. A phosphate-based fire retardant such as triethyl phosphate is now shown to work as a single solvent with potassium bis(fluorosulfonyl)imide at 0.9 m , in contrast to previous Li and Na systems where phosphates cannot work at low concentrations. This electrolyte is optimized at 2 m , where it exhibits the advantages of low cost, low viscosity, and high conductivity, as well as the formation of a uniform and robust salt-derived solid-electrolyte interphase layer, leading to non-dendritic K-metal plating/stripping with Coulombic efficiency of 99.6 % and a highly reversible graphite anode.     

Organometall‐Reaktionen in Wasser

Water has attracted significant attention as an alternative solvent for organometallic reactions because it is nontoxic, nonflammable, and inexpensive, and is easily separated from organic products. Organometallic reactions, like the palladium‐catalyzed couplings of organic halides with organoboron compounds (Suzuki) and organotin reagents (Stille), are among the most widely used reactions for the formation of carbon‐carbon bonds. Owing to the discovery of water‐soluble, sulfonated phosphane derivatives and particularly the design of water‐soluble palladium‐catalysts it was possible to import these reactions into aqueous media. Another efficient, metal‐catalyzed, carbon‐carbon bond‐forming process that is nowadays possible in aqueous media is the olefin metathesis. The approaches so far include the use of water‐soluble ruthenium‐catalysts, surfactants and additives, ultrasonication, the introduction of polar quaternary ammonium groups or the incorporation of PEG as a water solubilizing moiety. The last point bears also a great potential for further developments in the removal of ruthenium‐containing byproducts. Additionally, water is the ideal reaction environment for polar, water soluble substrates such as natural product or pharmaceuticals.