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

Involvement of a solute in a transition state without any effect on rate. The role of added pyridine in methanolysis of triphenylmethyl chloride in benzene solution

Removal of 2,4,6‐trinitrotoluene (TNT) and 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX) from aqueous solutions with surfactants

A copolymer of (meth)acrylic ester represented by a general formula (1) including a following repeating unit A and repeating unit B. In the general formula (1), R1 and R2 each independently represent hydrogen atom or methyl group; R3 represents an alkyl group having 1 to 4 carbon atoms; Y represents an atomic group forming an aromatic ring; x represents 1 to n, n represents the number of fluorine atoms which can be contained in the aromatic ring; and a and b each independently represent an integer of 1 or more.

Novel copolymer of methacrylic ester, composition, optical element and electric member

Organic dyes and rare earth chelates have been chosen and incorporated into the core regions of graded index (GI) polymer optical fibers (POF) as gain media. Since the synthetic polymer shows much better compatibility with organic fluorescent materials and is amenable to high active dopant concentrations, the doped POFs produce high gains in short lengths of fiber. We demonstrated that organic dye-doped polymer optical fiber amplifiers (POFA) cover a wide spectral range in the visible with a best observed gain of 37 dB in a Rhodamine B-doped POFA pumped at 550 nm. Also, with a GI POF doped with europium chelate of hexafluoroacetylacetone in tris form, we observed superfluorescence, evidenced by spectral narrowing and lifetime shortening. The prospect is that the wide choice of organic dyes and rare earth chelates offers optical amplifiers and superfluorescent sources for a variety of communication and sensor applications.

Polymer optical fiber amplifiers for communication and sensor applications

Electroluminescent devices were fabricated using plasma-polymerized carbon disulfide films, poly(CS2), and tris(8-quinolinolato)aluminum(III) complex, Alq, as the hole transport layer and the emitting layer, respectively. A cell structure of glass substrate/indium–tin–oxide/poly(CS2/Alq/Mg/Ag) was employed. Smooth hole injection from the electrode through the poly(CS2) layer and concomitant electroluminescence from the Alq layer were observed. Green emission with a luminance of 250 cd/m2 was achieved at a drive voltage of 14 V.

Yoshiyuki Okamoto

Papers

Involvement of a solute in a transition state without any effect on rate. The role of added pyridine in methanolysis of triphenylmethyl chloride in benzene solution

Removal of 2,4,6‐trinitrotoluene (TNT) and 1,3,5‐trinitro‐1,3,5‐triazacyclohexane (RDX) from aqueous solutions with surfactants

Novel copolymer of methacrylic ester, composition, optical element and electric member

Polymer optical fiber amplifiers for communication and sensor applications

Plasma‐polymerized carbon disulfide films as a hole transport layer in organic electroluminescent devices