Search

Large scale preparation of Li9V3(P2O7)3 (PO4)2 nanotubes is performed by a simple molten salt route without the use of a surfactant as a template.

The title catalyst, prepared by a traditional impregnation method or a chemical reduction protocol, is effective in the Heck reaction.

The synthesis of(3S, 5R, 6S)-3, 5-Dimethyl-6-isopropyl-3, 4, 5, 6-tetrahydropyran-2-one (1), the sex pheromone of the larval parasitoid M. grandii, is described. (3S, 5R, 6S)-3, 5-dimethyl-6-isopropyl-3, 4, 5, 6-tetrahydropyran-2-one, sex pheromone, larval parasitoid, M. grandii(2R, 4S)-2, 4-dimethyl-5-acetoxy-pentanol Download : Download full-size image

A series of β-substituted polythiophene derivatives was synthesized through palladium-catalyzed coupling reaction. Their structure-protein kinase C (PKC) inhibitory activity relationship was studied. The carboxaldehyde and hydroxymethyl derivatives of α-terthiophene were potent PKC inhibitors (IC 50 = 10 −7 M).

Three new polyoxometalates X7[PMo8O30] (X=Na+, 1; K+, 2; NH4+, 3) have been synthesized with the classical Keggin and/or Dawson heteropolymolybdophosphates and PCl5 in acetonitrile-water solutions via hydrothermal treatment. The three compounds were characterized by different analyses including IR, 31P NMR spectroscopy, elemental analysis, electrochemistry, thermogravimetric analysis (TGA) and powder X-ray diffraction (XRD). Single crystal X-ray analyses were carried out on Na7[PMo8O30] (1) and (NH4)7[PMo8O30] (3). Compound 1 and 3 crystallize in the orthorhombic system. The structure of compound 2 was confirmed by the IR spectra and powder XRD. All the three compounds contain the same octamolybdophosphate polyoxoanion [PMo8O30]7−, which consists of two Mo4O15 moieties linked by one central PO4 tetrahedron, leading to a remarkable sandglass-like structure.

Initial gas-phase reactions for a system containing silane (SiH4) and hydrogen (H2) were investigated using ab initio calculations at the MP2/6-311++g** level. Twenty-four minimum and 19 transition states were located on the potential energy surface of the neutral species containing one or two silicon atoms. The bonding nature of each species was elucidated by topological analyses of electron density using Bader's AIM theory. The reaction pathways were classified into three parts: Part (I) shows elimination of the first H2 and formation of disilane (Si2H6). Part (II) shows elimination of the second H2 and formation of five disilene (Si2H4) isomers. Part (III) shows elimination of the third H2 and formation of four disilyne (Si2H2) isomers. More energy is required to obtain species with less hydrogen content, and such species are more likely to be stabilized by a hydrogen bridged bond (Si−H−Si). Calculated IR spectra, dipole moments, and rotational constants were provided for comparison with the experiments.