Industrial nanoparticles are not developed to be compatible with in vitro cell culture assays which are carried out in isotonic solutions at physiological pH and often in the presence of proteins. The tendency of nanoparticles to deagglomerate or agglomerate is strongly sensitive to these parameters. The state of agglomeration and the protein corona bear an important influence on the level of toxic effects via the change of transport mechanisms and surface coating. Here we rigorously characterized the interaction of nanoparticles with physiological media for in vitro nanotoxicology experiments. Beyond adsorption of proteins on metal oxide and polymeric nanoparticles, we quantified nanoparticle deagglomeration due to adsorbing proteins acting as protection colloids. We report on previously neglected, but indispensable testing of sterility and measures to ensure it. Our findings result in a checklist of pre-requirements for dispersion of nanoparticles in physiological media and for reliable attribution of potential toxic effects.

A solid polymer electrolyte prepared by using a solvent-free, scalable technique is reported. The membrane is formed by low-energy ball milling followed by hot-pressing of dry powdered polyethylene oxide polymer, LiCF3 SO3 salt, and silane-treated Al2 O3 (Al2 O3 -ST) ceramic filler. The effects of the ceramic fillers on the properties of the ionically conducting solid electrolyte membrane are characterized by using electrochemical impedance spectroscopy, XRD, differential scanning calorimeter, SEM, and galvanostatic cycling in lithium cells with a LiFePO4 cathode. We demonstrate that the membrane containing Al2 O3 -ST ceramic filler performs well in terms of ionic conductivity, thermal properties, and lithium transference number. Furthermore, we show that the lithium cells, which use the new electrolyte together with the LiFePO4 electrode, operate within 65 and 90 °C with high efficiency and long cycle life. Hence, the Al2 O3 -ST ceramic can be efficiently used as a ceramic filler to enhance the performance of solid polymer electrolytes in lithium batteries.

Helices sind ein universelles Bauprinzip: Sie werden im atomaren Bereich genauso beobachtet wie bei interstellaren Spiralnebeln. Das auf dem Titelbild gezeigte zweikernige, dreisträngige Helicat enthält einen neuartigen Liganden mit Brenzcatechinato-und o-Benzoldithiolato-Donorgruppen. Es wird nur das Regioisomer mit paralleler Ligandenanordnung bestehend aus einem Enantiomerenpaar beobachtet. Mehr dazu erfahren Sie in der Zuschrift von F. E. Hahn et al. auf S. 4911 ff. Reaktionsmechanismen P. Espinet und A. M. Echavarren haben den Mechanismus der Stille-Kupplung gründlich unter die Lupe genommen. Welche Parameter die einzelnen Reaktionsschritte bestimmen, wird im Aufsatz auf S. 4808 ff. untersucht. Heterocyclensynthese Tetrathiafulvalen fungiert als Abgangsgruppe in einer oxidativen Cyclisierung, die zu einer neuen Bithiazol-Ringanordnung führt. Die Synthese und Eigenschaften dieses Heterocyclus beschreiben S. Decurtins et al. auf S. 4842 ff. DNA-FunktionseinheitenNanomechanische Gebilde sind vielversprechende Sonden für Messungen auf molekularer Ebene. N. C. Seeman et al. erklären auf S. 4854 ff. Aufbau und Funktion einer "DNA-Maschine" aus zwei tripelhelicalen DNA-Motiven und einer konventionellen DNA-Sequenz.

It takes two to tango: When ligand H4‐1 (see scheme) reacts with MoIV and TiIV, the different binding preferences of the O–O and S–S donor groups lead to the formation of the helicate [TiMo(1)3]4− with a parallel orientation of the ligand strands. With different cations, the supramolecular complexes {Λ,Λ‐[TiMo(1)3]‐(PNP)‐Δ,Δ‐[TiMo(1)3]}7− and {Δ,Δ‐[TiMo(1)3]‐Na‐Δ,Δ‐[TiMo(1)3]}7− can be crystallized. PNP=bis(triphenylphosphoranylidene)ammonium.

The benzene-o-dithiol/catechol ligands H4-2 and H4-3 react with [TiO(acac)2] to give the dinuclear, double-stranded anionic complexes [Ti2(L)2(mu-OCH3)2](2-) ([22](2-), L=2(4-); [23](2-), L=3(4-)). NMR spectroscopic investigations reveal that the complex anion [Ti2(2)2(mu-OCH3)(2)](2-) is formed as a mixture of three of four possible isomers/pairs of enantiomers, whereas only one isomer of the complex anion [Ti2(3)2(mu-OCH3)(2)](2-) is obtained. The crystal structure analysis of (PNP)2[Ti2(3)2(mu-OCH3)2] shows a parallel orientation of the ligand strands, whereas the structure determination for (AsPh4)2[Ti2(2)2(mu-OCH3)2] does not yield conclusive results about the orientation of the ligand strands due the presence of different isomers in solution, the possible co-crystallisation of different isomers and severe disorder in the crystal. NMR spectroscopy shows that ligand H4-3 reacts at elevated temperature with [TiO(acac)2] to give the triple-stranded helicate (PNP)4[Ti2(3)3] ((PNP)4[24]) as a mixture of two isomers, one with a parallel orientation of the ligand strands and one with an antiparallel orientation. Exclusively the triple-stranded helicates [Ti2(L)(3)](4-) ([25](4-), L=1(4-); [26](2-), L=4(4-)) are formed in the reaction of ligands H4-1 and H4-4 with [TiO(acac)2]. The molecular structures of Na(PNP)3[Ti2(1)3]CH(3)OHH(2)OEt(2)O (Na(PNP)3[25]CH(3)OHH(2)OEt(2)O) and Na(1.5)(PNP)(6.5)[Ti2(4)3]2.3 DMF (Na(1.5)(PNP)(6.5)[26]2.3 DMF) reveal a parallel orientation of the ligand strands in both complexes, which is retained in solution. The sodium cations present in the crystal structures lead to two different kinds of aggregation in the solid state. Na-[25]-Na-[25]-Na polymeric chains are formed from compound Na(PNP)3[25], with the sodium cations coordinated by the carbonyl groups of two ligand strands from two different [Ti2(1)3](4-) ions in addition to solvent molecules. In contrast to this, two [Ti2(4)3](4-) ions are connected by a sodium cation that is coordinated by the three meta oxygen atoms of the catecholato groups of each complex tetraanion to form a central {NaO6} octahedron in the anionic pentanuclear complex {[26]-Na-[26]}(7-).