Lanthanide-based luminescent hybrid materials.

Sterically encumbered Lewis acid and Lewis base combinations do not undergo the ubiquitous neutralization reaction to form "classical" Lewis acid/Lewis base adducts. Rather, both the unquenched Lewis acidity and basicity of such sterically "frustrated Lewis pairs (FLPs)" is available to carry out unusual reactions. Typical examples of frustrated Lewis pairs are inter- or intramolecular combinations of bulky phosphines or amines with strongly electrophilic RB(C(6)F(5))(2) components. Many examples of such frustrated Lewis pairs are able to cleave dihydrogen heterolytically. The resulting H(+)/H(-) pairs (stabilized for example, in the form of the respective phosphonium cation/hydridoborate anion salts) serve as active metal-free catalysts for the hydrogenation of, for example, bulky imines, enamines, or enol ethers. Frustrated Lewis pairs also react with alkenes, aldehydes, and a variety of other small molecules, including carbon dioxide, in cooperative three-component reactions, offering new strategies for synthetic chemistry.

Frustrated Lewis pairs: metal-free hydrogen activation and more.

Data Reduction And Error Analysis For The Physical Sciences

Heavy metal remediation of aqueous streams is of special concern due to recalcitrant and persistency of heavy metals in environment. Conventional treatment technologies for the removal of these toxic heavy metals are not economical and further generate huge quantity of toxic chemical sludge. Biosorption is emerging as a potential alternative to the existing conventional technologies for the removal and/or recovery of metal ions from aqueous solutions. The major advantages of biosorption over conventional treatment methods include: low cost, high efficiency, minimization of chemical or biological sludge, regeneration of biosorbents and possibility of metal recovery. Cellulosic agricultural waste materials are an abundant source for significant metal biosorption. The functional groups present in agricultural waste biomass viz. acetamido, alcoholic, carbonyl, phenolic, amido, amino, sulphydryl groups etc. have affinity for heavy metal ions to form metal complexes or chelates. The mechanism of biosorption process includes chemisorption, complexation, adsorption on surface, diffusion through pores and ion exchange etc. The purpose of this review article is to provide the scattered available information on various aspects of utilization of the agricultural waste materials for heavy metal removal. Agricultural waste material being highly efficient, low cost and renewable source of biomass can be exploited for heavy metal remediation. Further these biosorbents can be modified for better efficiency and multiple reuses to enhance their applicability at industrial scale.

Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions

White light‐emitting electroluminescent devices were fabricated using poly(N‐vinylcarbazole) (PVK) as a hole‐transporting emitter layer and a double layer of 1,2,4‐triazole derivative (TAZ) and tris(8‐quinolinolato)aluminum(III) complex (Alq) as an electron transport layer. The PVK layer was doped with fluorescent dyes such as blue‐emitting 1,1,4,4‐tetraphenyl‐1,3‐butadiene, green‐emitting coumarin 6, and orange‐emitting DCM 1. A cell structure of glass substrate/indium‐tin‐oxide/doped PVK/TAZ/Alq/Mg:Ag was employed. White emission covering a wide range of the visible region and a high luminance of 3400 cd/m2 were obtained at a drive voltage of 14 V.

White light‐emitting organic electroluminescent devices using the poly(N‐vinylcarbazole) emitter layer doped with three fluorescent dyes

Viologen Derivative Containing Polysiloxane as an Electron-Transfer Mediator in Amperometric Glucose Sensors

Polymerisation de dicetene avec BF 3 OEt 2 , WCl 6 , AIBN et peroxyde de benzoyle. Conductivites electriques de la poly-β-dicetone et des complexes de transfert de charge avec TCNQ. Silylation du polymere avec SiCl 2 (CH 3 ) 2

Electrical conductive materials based on poly(β-diketone)

Copolymerizations of hexafluoroisobutylene (HFIB) with vinyl pentafluorobenzoate (VPFB) and vinyl trifluoroacetate (VTFA) were carried out in bulk using perfluorodibenzoyl peroxide as the radical initiator. The copolymers obtained were characterized by proton and fluorine NMR spectroscopy. The monomer reactivity ratios in the polymerization of HFIB with VPFB were r1 (HFIB) = 0, r2 (VPFB) = 0.373, and r1r2 = 0. The results indicated that these copolymers have alternating structures. Similarly, the copolymers of HFIB and VTFA also showed alternating structures. The films of HFIB-co-VPFB were prepared by casting THF solution of polymers. Films obtained were flexible and transparent. The refractive indices of copolymers were 1.4549, 1.4490, and 1.4438 at 532, 633, and 839 nm, respectively. The average Tgs of HFIB-co-VTFA and HFIB-co-VPFB were 52 and 71 °C, respectively. From these results, the Tg of the hypothetical HFIB homopolymer is postulated to be in between 70 and 90 °C, which may be useful in the assessment of Tgs of HFIB copolymers with other vinyl monomers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Alternating copolymers of hexafluoroisobutylene with vinyl trifluoroacetate and vinyl pentafluorobenzoate

Elimination reactions under high pressure. Reactions of alkyl iodides with 2,6,N,N-tetramethylaniline

PURPOSE: To bring oxidoreductase into close contact with vector and to prevent the diffusion of vector species from an electrode surface by using artificial redox compound having covalent bond to flexible polymer principal chain insoluble in electron moving vector. CONSTITUTION: An enzyme electrode is manufactured by mixing graphite powder, siloxane-ferrocene polymer and glucose oxidase, mixing the obtained mixture with paste 3, and filling in the well at the bottom of a cylindrical electrode housing 1 made of electrically insulating material. The material of electron collector 2 is preferably graphite paste, or may be silver, platinum, nickel, glassy carbon or tin oxide. With the constitution, when oxidoreductase and enzyme are catalytic active, the electrons are held on the outer surface of the collector 2 in the state that the vector of polymer for moving electrons to the collector 2 is immobilized. COPYRIGHT: (C)1990,JPO

Yoshiyuki Okamoto

Papers

Viologen Derivative Containing Polysiloxane as an Electron-Transfer Mediator in Amperometric Glucose Sensors

Electrical conductive materials based on poly(β-diketone)

Alternating copolymers of hexafluoroisobutylene with vinyl trifluoroacetate and vinyl pentafluorobenzoate

Elimination reactions under high pressure. Reactions of alkyl iodides with 2,6,N,N-tetramethylaniline

Electrochemical biosensor using immobilized enzyme and redox polymer