Solid polymer electrolytes with high ionic conductivities are prepared by using poly(ethylene oxide) (PEO) and poly(vinylidene fluoride‐co‐hexafluoropropylene) (P(VDF‐HFP)) as polymer matrixes, succinonitrile (SN) as an additive, and lithium bis‐trifluoromethanesulfonimide (LiTFSI) and lithium bisperfluoroethylsulfonylimide (LiBETI) as salts. In these systems, the introduction of succinonitrile into the polymer electrolytes increases the material's ionic conductivity and conveys excellent mechanical properties. The described composites, with their beneficial combination of mechanical and electric properties, are expected to have significant potential for lithium batteries.

Neuroglobin (Ngb) is a recently discovered protein in vertebrate brain tissue that belongs to the globin family of proteins. It has been implicated in the neuronal response to hypoxia or ischemia, although its physiological role has been hitherto unknown. Ngb is hexacoordinate in the ferrous deoxy form under physiological conditions. To bind exogenous ligands like O2 and CO, the His E7 endogenous ligand is displaced from the sixth coordination. By using infrared spectroscopy and nanosecond time-resolved visible spectroscopy, we have investigated the ligand-binding reaction over a wide temperature range (3-353 K). Multiple, intrinsically heterogeneous distal heme pocket conformations exist in NgbCO. Photolysis at cryogenic temperatures creates a five-coordinate deoxy species with very low geminate-rebinding barriers. The photodissociated CO is observed to migrate within the distal heme pocket even at 20 K. Flash photolysis near physiological temperature (275-353 K) exhibits four sequential kinetic features: (i) geminate rebinding (t < 1 s); (ii) extremely fast bimolecular exogenous ligand binding (10 s < t < 1 ms) with a nontrivial temperature dependence; (iii) endogenous ligand binding (100 s < t < 10 ms), which can be studied by using flash photolysis on deoxy Ngb; and (iv) displacement of the endogenous by the exogenous ligand (10 ms < t < 10 ks). All four processes are markedly nonexponential, suggesting that Ngb fluctuates among different conformations on surprisingly long time scales.G lobins are proteins that bind dioxygen and other small ligands at the central iron of a heme prosthetic group embedded in a highly conserved ␣-helical ''globin'' fold. Hemoglobin (Hb) and myoglobin (Mb) are the most prominent members of this protein family (1). Interrelations among structure, dynamics, and function in globins have been investigated in great detail, most likely more thoroughly than for any other protein family. Mb especially has, for a long time, served as a paradigm in the biological physics of proteins (2, 3).Recently, two new members have joined the globin family, cytoglobin (4) and neuroglobin (Ngb) (5). The latter consists of a single chain of 151 aa. Ngb, which occurs in neurons, has less than 25% sequence identity with Mb or Hb but nevertheless displays all key determinants of the globin fold (6). It has moderate oxygen affinity and seems most closely related to the globin found in the glial cells of the annelid Aphrodite (7). The discovery of a six-coordinate heme in the deoxy form of Ngb (5), with the His E7 side chain occupying the sixth coordination, came somewhat as a surprise because it was believed for a long time that a pentacoordinate heme iron, with a vacant ligandbinding site, was a common characteristic of globins. In recent years, however, hexacoordinate globins also have been isolated from bacteria, unicellular eukaryotes, and plants [nonsymbiotic Hbs, nsHbs (8,9), and truncated Hbs, trHbs (10)]. In these proteins, the exogenous ligand has to compete with an intramolecular side chain for ...

The aim of this contribution is twofold. First of all it introduces a new class of electrolytes, viz. composites consisting of liquid non-aqueous salt solutions and solid insulating particles. At high second phase content, the investigated systems show strongly enhanced conductivities (compared to the non-aqueous solution) and are better described as ªsoggy sandº electrolytes, a viscous grain ensemble wetted by the liquid. Unlike solid±liquid composites, [1,2] the effects are not simply additive;rather they are synergistic in the sense that the overall conductivity is significantly (up to one order of magnitude) higher than in both of the constituent phases, an astonishing finding which will be ascribed below to interfacial interaction. These new electrolytes combine very high conductivities with the favorable mechanical properties of soft matter. We also provide evidence for significant conductivity enhancements (leading to very high absolute overall values of 1.2 10 ±2 X ±1 cm ±1

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Poly(ionic liquids)-based gel polymer electrolytes containing high lithium salt concentration ionic liquids are demonstrated.

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Ion transport mechanism in lithium perchlorate (LiClO(4))-succinonitrile (SN), a prototype of plastic crystalline soft matter electrolyte is discussed in the context of solvent configurational isomerism and ion solvation. Contributions of both solvent configurational isomerism and ion solvation are reflected in the activation energy for ion conduction in 0-1 M LiClO(4)-SN samples. Activation energy due to solvent configurational changes, that is, trans-gauche isomerism is observed to be a function of salt content and decreases in presence of salt (except at high salt concentrations, e.g. 1 M LiClO(4)-SN). The remnant contribution to activation energy is attributed to ion-association. The X-ray diffraction of single crystals obtained using in situ cryo-crystallography confirms directly the observations of the ionic conductivity measurements. Fourier transform infrared spectroscopy and NMR line width measurements provide additional support to our proposition of ion transport in the prototype plastic crystalline electrolyte.