Quasi-Hopf twistors for elliptic quantum groups

The Yang-Baxter equation admits two classes of elliptic solutions, the vertex type and the face type. On the basis of these solutions, two types of elliptic quantum groups have been introduced (Foda et al. [FIJKMY1], Felder [Fe]). Frønsdal [Fr1, Fr2] made a penetrating observation that both of them are quasi-Hopf algebras, obtained by twisting the standard quantum affine algebraU _q(g). In this paper we present an explicit formula for the twistors in the form of an infinite product of the universalR matrix ofU _q(g). We also prove the shifted cocycle condition for the twistors, thereby completing Frønsdal's findings.This construction entails that, for generic values of the deformation parameters, the representation theory forU _q(g) carries over to the elliptic algebras, including such objects as evaluation modules, highest weight modules and vertex operators. In particular, we confirm the conjectures of Foda et al. concerning the elliptic algebraA _q,p ( ).Dedicated to Professor Mikio Sato on the occasion of his seventieth birthday     

π-conjugated phosphasilenes stabilized by fused-ring bulky “Rind” groups

Recent progress in the chemistry of π-conjugated phosphasilenes stabilized by bulky protecting groups based on a fused-ring octa-R-substituted s-hydrindacene skeleton (Rind groups) is reviewed. The phosphasilenes with a variety of aryl substituents at the silicon atom are covered in detail. The X-ray crystallography analysis showed the highly coplanar π-framework reinforced by the perpendicularly-fixed Rind groups. Strong π–π* absorptions have been observed, demonstrating the extension of π-conjugation over the skeleton. The DFT calculations indicated that the LUMO involves significant contribution by the 3pπ*(Si–P)–2pπ*(carbon π-electron system) conjugation. The preparation of the gold(I) complexes of the π-conjugated phosphasilenes is also included.     

The first observation of electroluminescence from di(2-naphthyl)disilene, an Si=Si double bond-containing π-conjugated compound

Air-stable, room-temperature emissive di(2-naphthyl)disilene, protected by the bulky 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl (Eind) groups, can emit light in an organic light-emitting diode, thus providing the first experimental demonstration of electroluminescence from the heavy group 14 unsaturated compounds.     

Preparation of low flow-resistant methacrylate-based monolithic stationary phases of different hydrophobicity and the application to rapid reversed-phase liquid chromatographic separation of alkylbenzenes at high flow rate and elevated temperature

Low flow-resistant alkyl methacrylate-based monolithic stationary phases of different hydrophobicity were constructed for reversed-phase capillary liquid chromatography by thermally initiated radical polymerization of respective methacrylate ester monomer with different alkyl chain (C2, C4, C6, C12, C18) and ethylene glycol dimethacrylate (EDMA) in a 250 microm i.d. fused silica capillary. The hydrophobicity was basically controlled by changing the length and/or the density of the alkyl-chain, while the composition and the ratio of porogenic solvent were adjusted to obtain highly permeable rigid monoliths with adequate column efficiency. Among the prepared monolithic stationary phases, C18-methacrylate monoliths polymerized from a binary porogenic solvent of isoamyl alcohol and 1,4-buthandiol exhibited the most promising performance in terms of hydraulic resistance and column efficiency. The pressure drops of 20-cm long monolithic columns were below approximately 0.4 MPa at a normal linear velocity of 1mm/s (a flow rate of 3 microL/min), and the numbers of theoretical plates for alkylbenzenes mostly exceeded 3000 plates/20 cm. The produced monolithic columns had good mechanical strength for high pressure and temperature, and could be properly operated even at a temperature of 80 degrees C and at a pressure of at least 33 MPa. At 80 degrees C, the theoretical plate numbers reached 6000 plates/20 cm because of the enhanced mass transfer. Due to the novel hydraulic resistance and mechanical strength, the separation time could be reduced 120-fold simply by raising the flow rate and column temperature.     

沉积-沉淀-微波干燥法制备金属氧化物负载的金簇合物及其在CO氧化和 硫化物氧化反应中的催化性能

采用沉积-沉淀法再辅以微波干燥和焙烧制备了金属氧化物负载的金簇合物和小的金纳米粒子.干燥方法影响了金颗粒尺寸.在炉干燥过程中Au(III)因部分还原而致使Au聚集.相反,在微波干燥下,因快速和加热均一而使Au(III)得以保持,在Al2O3上负载的Au颗粒尺寸小至1.4 nm.该法可用于具有几种不同微波吸收效率的金属氧化物载体,如MnO2,Al2O3和TiO2.这些催化剂在低温CO氧化和硫化物选择有氧氧化反应中的催化活性比常规方法制备的更高.