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Oxide Groups (oxide + groups)

Distribution by Scientific Domains

Polymers and Materials Science	60%

Selected Abstracts

Multifunctional Deep-Blue Emitter Comprising an Anthracene Core and Terminal Triphenylphosphine Oxide Groups

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2009
Chen-Han Chien
Abstract A highly efficient blue-light emitter, 2- tert -butyl-9,10-bis[4,-(diphenyl-phosphoryl)phenyl]anthracene (POAn) is synthesized, and comprises electron-deficient triphenylphosphine oxide side groups appended to the 9- and 10-positions of a 2- tert -butylanthracene core. This sophisticated anthracene compound possesses a non-coplanar configuration that results in a decreased tendency to crystallize and weaker intermolecular interactions in the solid state, leading to its pronounced morphological stability and high quantum efficiency. In addition to serving as an electron-transporting blue-light-emitting material, POAn also facilitates electron injection from the Al cathode to itself. Consequently, simple double-layer devices incorporating POAn as the emitting, electron-transporting, and -injecting material produce bright deep-blue lights having Commission Internationale de L'Eclairage coordinates of (0.15,0.07). The peak electroluminescence performance was 4.3% (2.9 cd A,1). For a device lacking an electron-transport layer or alkali fluoride, this device displays the best performance of any such the deep-blue organic light-emitting diodes reported to date. [source]

Production of microporous resins for heavy-metal removal.

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008

Abstract Ion-exchange polymers were used successfully in water-treatment operations. In this study, three ion-exchange resins based on 4-vinylpyridine and divinylbenzene functionalized with N -oxide groups were obtained. Their ion-adsorption properties were measured in solutions containing chromium at concentrations of 4 and 500 ppm with column and batch equilibrium techniques. The removal efficiency of the chromium ions with HCl was observed to increase after the protonation of the N -oxide groups. The resins could be reused after 10 cycles with the metal removal efficiency maintained at higher than 95%. These studies evidenced a strong correlation between the morphology and ionic group content in the resin and its chromium ion sorption capability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source]

Synthesis and properties of new fluorinated polymers bearing pendant imidazole groups for fuel cell membranes operating over a broad relative humidity range

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2010
Guillaume Frutsaert
Abstract New alternating copolymers comprising a chlorotrifluorinated backbone and imidazole-terminated pendant ethylene oxide groups have been prepared with a view to their use as a component of proton-conducting membranes in polymer electrolyte fuel cells. A vinyl ether containing an imidazole (Imi) function protected by a benzyl group (BVI) was first synthesized in a three-step reaction. It was then copolymerized in solution with chlorotrifluoroethylene (CTFE) by conventional radical copolymerization leading to alternating poly(BVI-alt-CTFE) copolymers in good yields. Deprotection of the benzyl group under hydrogen produced a chlorotrifluorinated poly(Imi-alt-CTFE) copolymer. The polymer was subsequently used to form blend membranes with sulfonated poly(ether ether ketone) (sPEEK). The conductivity of blend membranes of poly (Imi-alt-CTFE) with sPEEK lies in the range of 4,10 mS cm,1 at 40,70 °C and, for blend membranes rich in poly(Imi-alt-CTFE), is little dependent on relative humidity between 30 and 100%. It is surmised that the polymer and membrane composition favor microstructural phase separation into chlorotrifluorinated polymer backbone domains and regions in which imidazole groups are clustered. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 223,231, 2010 [source]

Association between nitrous oxide and the incidence of postoperative nausea and vomiting in adults: a systematic review and meta-analysis

ANAESTHESIA, Issue 4 2010
J. Fernández-Guisasola
Summary Some, but not all studies have suggested intra-operative use of nitrous oxide is correlated with postoperative nausea and vomiting. We performed a meta-analysis of randomised controlled trials to compare the incidence of nausea and vomiting in adults following general anaesthesia with or without nitrous oxide. We retrieved 30 studies (incorporating 33 separate trials) that investigated a ,nitrous oxide group' (total 2297 patients) vs a ,no-nitrous oxide group' (2301 patients). Omitting nitrous oxide significantly reduced postoperative nausea and vomiting (pooled relative risk 0.80, 95% CI 0.71,0.90, p = 0.0003). However, the absolute incidence of nausea and vomiting was high in both the nitrous oxide and no-nitrous oxide groups (33% vs 27%, respectively). In subgroup analysis, the maximal risk reduction was obtained in female patients (pooled relative risk 0.76, 95% CI 0.60,0.96). When nitrous oxide was used in combination with propofol, the antiemetic effect of the latter appeared to compensate the emetogenic effect of nitrous oxide (pooled relative risk 0.94, 95% CI 0.77,1.15). We conclude that avoiding nitrous oxide does reduce the risk of postoperative nausea and vomiting, especially in women, but the overall impact is modest. [source]

Bis[,3 -1,8-bis(triisopropylsilylamido)naphthalene]bis(tetrahydrofuran)di-,3 -oxido-dimanganese(III)disodium

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010
Alexander J. Blake
The solid-state structure of the title compound, [Na2Mn2(C32H56N2OSi2)2O2] or [1,8-C10H6(NSiiPr3)2Mn(,3 -O)Na(THF)]2, which lies across a crystallographic twofold axis, exhibits a central [Mn2O2Na2]4+ core, with two oxide groups, each triply bridging between the two MnIII ions and an Na+ ion. Additional coordination is provided to each MnIII centre by a 1,8-C10H6(NSiiPr3)2 [1,8-bis(triisopropylsilylamido)naphthalene] ligand and to the Na+ centres by a tetrahydrofuran molecule. The presence of an additional Na...H,C agostic interaction potentially contributes to the distortion around the bridging oxide group. [source]