CATALYTIC WET PEROXIDE OXIDATION OF HYDROQUINONE WITH Co（II）/ACTIVE CARBON CATALYST LOADED IN STATIC BED

Catalysts based on Co（II） supported on active carbon were prepared and loaded in static bed. The hydroquinone would be degraded completely after treated by Catalytic wet peroxide oxidation method with Co（II）/active carbon catalyst. After activate treatment, the active carbon was immerged in cobaltous nitrate solution, then put into a drying oven, Co（II） could be loaded on the micro-surface of carbon. Taking the static bed as the equipment, the absorption of active carbon and catalysis of Co（II） was used to reduce activation energy of hydroquinone. Thus hydroquinone could be drastically degraded and the effluent can be drained under the standard. Referring to Fenton reaction mechanism, experiment had been done to study the heterogeneous catalyzed oxidation mechanism of Co（II）. The degradation rate of hydroquinone effluent could be achieved to 92% when treated in four columns at H2O2 concentration 10%, reaction temperature 40 ℃, pH 5 and reaction time 2.5h.     

Structure and coordination environment of the zinc complex with vanillin of double-stranded helix

The structure and coordination environment of unusually double-stranded helix of complex [Zn(C₈H₇O₃)₂(H₂O)₂] are studied experimentally and by the density functional theory (DFT) method. The Zn²⁺ ion coordinates six oxygen atoms of deprotonated vanillin and water molecules forming an octahedron. The intermolecular hydrogen bonds and π interactions of the vanillin fragments contributed to the formation of the double-stranded helical supramolecular structure in the crystal. Counterpoise geometric parameters of the calculation agree with the crystal structure determined by experiment. The stabilization energy between the donor and acceptor obtained from an analysis of natural bond orbitals of the indicated six ligand oxygen atoms act as electron donor to Zn²⁺ ion. The results of the density functional theory on the complex demonstrate that the different coordinated oxygen atoms, which have different chemical environment, distort the coordination octahedron. The text was submitted by the authors in English.     

A facile synthesis of N-sulfonyl and N-sulfinyl aldimines under Barbier-type conditions

A convenient synthesis of N-sulfonyl- and N-sulfinylimines by the condensation of aldehydes with sulfonyl or sulfinyl amides in the presence of benzyl bromide and zinc dust at room temperature under the Barbier-type conditions is reported. The procedure is lauded by its simplicity and adaptability to aromatic, alpha,beta-unsaturated, and aliphatic aldehydes.     

Preparation, photo- and electro-luminescent properties of a novel complex of Tb (III) with a tripod ligand

A novel Tb(III) complex TbL (L=tris[2-(2-carboxyphenoxy)ethyl]amine, H3L) was synthesized and characterized by means of elemental analyses, IR spectra, thermal analyses, and molar conductivity measurement. The photoluminescent properties of the complex were investigated. In addition, PVK doping Tb(III) complex was fabricated as the emissive layer by spin-coating and its electroluminescent properties were studied, in which the structure of the device was ITO (indium tin oxide)/PVK (polyvinylcarbazole)/PVK: TbL/PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole)/LiF/Al. It was indicated that pure green and narrow bandwidth emission at 545nm from photoluminescence of TbL complex film and the organic electroluminescent device is the characteristic emission of Tb(III) ion, and the electroluminescence spectrum of the device was very similar to that of the photoluminescence of TbL complex film. The lowest triplet level of the ligand was calculated from the phosphorescence spectrum of GdL in N,N-dimethyl formamide (DMF) dilute solution determined at 77K, and the energy transfer mechanisms in TbL complex were discussed.     

Fire retardant synergism between melamine and triphenyl phosphate in poly(butylene terephthalate)

The fire retardant efficiency of melamine (MA) and triphenyl phosphate (TPP) in poly(butylene terephthalate) (PBT) was studied by the limiting oxygen index (LOI) and the UL94 test. On adding 10 wt. % MA and 20 wt. % TPP, LOI increased from 20.9 to 26.6 and the UL94 V-0 rating was achieved. SEM and DSC analyses show that the fire retardants are compatible with PBT and facilitate crystallization of PBT. The occurrence of an interaction between MA + TPP and PBT was elucidated by TGA, dynamic FTIR, and pyrolysis/GC/MS. MA + TPP changes the degradation path of PBT and modifies the compositions of the gas and condensed-phase products.     

Synthesis of Cyanobenzaldehydes （m—,o—,p—）by Molecular oxygen Oxidation Methods

Cyanobenzaldehydes (m-,o-,p-) were synthesized by oxidation of corresponding tolunitriles with molecular oxygen,catalyzed by cobalt acetate and sodium bromide.     

催化荧光法测定痕量铬(Ⅵ)

在ＨＡc－ＮaＡc缓冲介质中,痕量铬（Ⅵ）对过氧化氢与罗丹明Ｂ的氧化还原反应具有催 化作用,使罗丹明Ｂ的荧光减弱,据此建立了催化荧光法测定痕量铬（Ⅵ）的新方法。方法的检测限为３．３２ｒｇ／Ｌ,测定范围为０．０１～０．１６ｍｇ／ＬＣｒ（Ⅵ）。本法已用于测定电镀液、电镀废液中痕量Ｃr（Ⅵ）,结果令人满意。     

Programmable Live-Cell CRISPR Imaging with Toehold-Switch-Mediated Strand Displacement

The widespread application of CRISPR-Cas9 has transformed genome engineering. Nevertheless, the precision to control the targeting activity of Cas9 requires further improvement. We report a toehold-switch-based approach to engineer the conformation of single guide RNA (sgRNA) for programmable activation of Cas9. This activation circuit is responsive to multiple inputs and can regulate the conformation of the sgRNA through toehold-switch-mediated strand displacement. We demonstrate the orthogonal suppression and activation of Cas9 with orthogonal DNA inputs. Combination of toehold switches leads to a variety of intracellular Cas9 activation programs with simultaneous and orthogonal responses, through which multiple genome loci are displayed in different colors in a controllable manner. This approach provides a new route for programing CRISPR in living cells for genome imaging and engineering.     

A density functional theory approach to mushroom-like platinum clusters on palladium-shell over Au core nanoparticles for high electrocatalytic activity

Recently, it was found that Pt clusters deposited on Pd shell over Au core nanoparticles (Au@Pd@Pt NPs) exhibit unusually high electrocatalytic activity for the electro-oxidation of formic acid (P. P. Fang, S. Duan, et al., Chem. Sci., 2011, 2, 531-539). In an attempt to offer an explanation, we used here carbon monoxide (CO) as probed molecules, and applied density functional theory (DFT) to simulate the surface Raman spectra of CO at this core-shell-cluster NPs with a two monolayer thickness of Pd shell and various Pt cluster coverage. Our DFT results show that the calculated Pt coverage dependent spectra fit the experimental ones well only if the Pt clusters adopt a mushroom-like structure, while currently the island-like structure is the widely accepted model, which follows the Volmer-Weber growth mode. This result infers that there should be a new growth mode, i.e., the mushroom growth mode as proposed in the present work, for Au@Pd@Pt NPs. We suggest that such a mushroom-like structure may offer novel active sites, which accounts for the observed high electrocatalytic activity of Au@Pd@Pt NPs.