Reactions of methyltris(triarylphosphine)cobalt : I. Formation of biaryls

Methyltris(triarylphosphine)cobalt (Ar₃P)₃CoCH₃, decomposes in solutions of THF, benzene or chlorobenzene to yield biaryls. Coupling to biaryls occurs at the ring carbon originally bonded to phosphorus. Mixed biaryls are obtained from crossover reactions of complexes bearing different triarylphosphine ligands and reactions of complexes with free triarylphosphines.     

Characterization of Nested Hollow Inorganic Fullerene-like Tungsten Disulfide Nanoparticles Prepared by Solid-Gas Reaction

Non-carbon inorganic fullerene-like(IF) nanoscale materials have recently attracted intense interest due to their nested hollow and nanotube structures,In this letter,IF-WS2 nanoparticles prepared by solid-gas reaction were characterized by X-ray diffraction,Scanning electron microscopy and transmission electron microscopy.The results show that the IF-WS2 nanoparticles have a nested hollow closed spherical structure with diameter of 100-150mm.     

Catalytic oxidative coupling of diols by Ru3(CO)12

Ru₃(CO)₁₂ acts as a homogeneous catalyst precursor for the transformation of αω-diols to polyesters and lactones.     

Multichannel laser resonators — an experimental study

The output characteristics of several large-area multichannel unstable resonators are presented. The conventional unstable resonator and a novel toric unstable resonator, in both confocal and nonconfocal configurations, have been studied. Output beam profiles, optical energy extraction, beam focusability, resonator alignment properties and polarization states of the various resonators have been analysed in depth.     

H-transfer catalysis with Ru3(CO)12

Ru₃(CO)₁₂ , in the presence of tolane, catalyzes the formation of esters from the following three systems: alcohol + aldehyde, alcohol and aldehyde.     

The effects of meta-cognitive instruction on third and sixth graders solving word problems

This study examined the differential effects of a meta-cognitive instruction, called IMPROVE, on third and sixth graders’ solution of word problems. In particular, the study focused on the solution of two kinds of word problems: with consistent and with inconsistent language. Participants were 194 Israeli students who studied in third (N = 110) and sixth (N = 84) grades. All students were administered pre- and post-tests constructed of 16 word problems with consistent and inconsistent language. About half of the students within each grade level were exposed to IMPROVE and the others studied under a ‘traditional’ teaching method. The findings indicate that at both grade levels the IMPROVE students significantly outperformed their counterparts in the control group, but third graders benefited from IMPROVE more than sixth graders. In addition, the study indicates that the gap in achievement between IMPROVE and control groups was larger on word problems with inconsistent language compared to word problems with consistent language. The theoretical and practical implications of the study are discussed.     

New microviridins from a water bloom of the cyanobacterium Microcystis aeruginosa

Three new microviridins namely, SD1684 (1), SD1634 (2), and SD1652 (3), were isolated from the hydrophilic extract of Microcystis aeruginosa. The planar structures of compounds 1-3 were determined by homonuclear and inverse-heteronuclear 2D-NMR techniques as well as by high-resolution mass spectrometry. The absolute configuration of the asymmetric centers was studied using Marfey's method for HPLC. Compounds 1-3 contain l-threo-β-hydroxy aspartic acid as a building block of the peptide chain. This is the first example where microviridins contain non-proteinogenic amino acid in their structure. Compound 2 is a mild serine protease inhibitor.     

Novel carboxylated pyrrole- and carbazole-based monomers. Synthesis and electro-oxidation features

Carboxylated pyrrole (Pyr, a index)- and carbazole (Cbz, b index)-containing monomers 6-7a/b and 9a/b have been readily synthesized from the monobenzyl ester of L-glutamic acid and triamine 2 using Clauson-Kaas and amide coupling reactions. In contrast to Pyr-containing compounds 6-7a, and 9a, the three Cbz-containing monomers 6-7b, and 9b have been found electroactive and were successfully electropolymerized on a Pt electrode resulting in the deposition of corresponding insoluble electroconducting polyCOOH polyCbz-films poly(6-7b) and poly(9b).     

Separation and detection of VX and its methylphosphonic acid degradation products on a microchip using indirect laser-induced fluorescence

The application of indirect LIF (IDLIF) technique for on-chip electrophoretic separation and detection of the nerve agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothiolate (VX) and its major phosphonic degradation products, ethyl methylphosphonic acid (EMPA) and methylphosphonic acid (MPA) was demonstrated. Separation and detection of MPA degradation products of VX and the nerve agent isopropyl methylphosphonofluoridate (GB) are presented. The negatively charged dye eosin was found to be a good fluorescent marker for both the negatively charged phosphonic acids and the positively charged VX, and was chosen as the IDLIF visualization fluorescent dye. Separation and detection of VX, EMPA, and MPA in a simple-cross microchip were completed within less than a minute, and consumed only a 50 pL sample volume. A characteristic system peak that appeared in all IDLIF electropherograms served as an internal standard that increased the reliability of peak identification. The negative peak of both VX and the MPAs is in agreement with indirect detection theory and with previous reports in the literature. The LOD of VX and EMPA by IDLIF was 30 and 37 microM, respectively. Despite the fact that the detection sensitivity is relatively low, the rapid simultaneous on-chip analysis of both VX and its degradation products as well as the separation and detection of the MPA degradation products of both VX and GB, increases detection reliability and may present a choice when sensitivity is not critical compared with speed and simplicity of the assay.