Synthesis of multifunctional polymer containing Ni‐Pd NPs via thiol‐ene reaction for one‐pot cascade reactions

Recently, acid–base bifunctional catalysts have been considered due to their abilities, such as the simultaneous activation of electrophilic and nucleophilic species and their high importance in organic syntheses. However, the synthesis of acid–base catalysts is problematic due to the neutralization of acidic and basic groups. This work reports a facial approach to solve this problem via the synthesis of a novel bifunctional polymer using inexpensive materials and easy methods. In this way, at the first step, heterogeneous poly (styrene sulfonic acid‐n‐vinylimidazole) containing pentaerythritol tetra‐(3‐mercaptopropionate) (PETMP) and trimethylolpropane trimethacrylate (TMPTMA) cross‐linkers were synthesized in the pores of a mesoporous silica structure using click reaction as a novel bifunctional acid–base catalyst. After that, Ni‐Pd nanoparticles supported on poly (styrenesulfonic acid‐n‐vinylimidazole)/KIT‐6 as a novel trifunctional heterogeneous acid–base‐metal catalyst was prepared. The prepared catalysts were characterized by various techniques like FT‐IR, TGA, ICP‐AES, DRS‐UV, TEM, FE‐SEM, EDS‐Mapping, and XRD. The synthesized catalysts were efficiently used as bifunctional/trifunctional catalysts for one‐pot, deacetalization‐Knoevenagel condensation and one‐pot, three‐step and a sequential reaction containing deacetalization‐Knoevenagel condensation‐reduction reaction. It is important to note that the synthesized catalyst showing high chemo‐selectivity for the reduction of nitro group, alkenyl double bond and ester group in the presence of nitrile. Moreover, it was found that the different nanoparticles including Ni, Pd, and alloyed Ni‐Pd showing different chemo‐selectivity and catalytic activity in the reaction.     

两个三(邻溴苄基)锡羧酸酯的合成、结构及抗肿瘤活性

合成了2个有机锡羧酸酯化合物三(邻溴苄基)锡噻吩2-甲酸酯(1)和三(邻溴苄基)锡肉桂酸酯(2).通过元素分析、红外光谱、核磁共振谱(1H、13C和119Sn)、差热分析、X射线单晶衍射方法对1和2进行了结构表征,对其结构进行了量子化学从头计算.结果 显示,化合物1和2均为单锡核结构,锡原子均为四配位的畸变四面体构型....     

Enhanced Electrochemiluminescence from a Stoichiometric Ruthenium(II)–Iridium(III) Complex Soft Salt

Electrochemiluminescence (ECL) and electrochemistry are reported for a heterometallic soft salt, [Ru(dtbubpy)₃][Ir(ppy)₂(CN)₂]₂ ( [Ir][Ru][Ir] ), consisting of a 2:1 ratio of complementary charged Ru and Ir complexes possessing two different emission colors. The [Ru]²⁺ and [Ir]^? moieties in the [Ir][Ru][Ir] greatly reduce the energy required to produce ECL. Though ECL intensity in the annihilation path was enhanced 18× relative to that of [Ru(bpy)₃]²⁺, ECL in the co‐reactant path with tri‐n‐propylamine was enhanced a further 4×. Spooling spectroscopy gives insight into ECL mechanisms: the unique light emission at 634 nm is due to the [Ru]²⁺* excited state and no [Ir]^?* was generated in either route. Overall, the soft salt system is anticipated to be attractive and suitable for the development of efficient and low‐energy‐cost ECL detection systems.     

（2D ＋ 1D） Hydrogen Bond Structure Constructed. from Dendrimer Precursor

The title compound, CsH12NO4＂2（H20） 1, was obtained by slow diffusion of cop- per sulfate solution into the solution of 1,4-N,N-bis[tri（hydroxy）methyl]terephthaldiamide in DMSO and characterized by elemental analysis and infrared spectra. The crystal of 1 crystallizes in the monoclinic space group P2Jc with a = 12.943（7）, b = 6.446（3）, c = 14.157（5） A, fl = 119.76（3）, V = 1025.4（9）/3, Z = 2, C16H32N2OI2, Mr= 444.44, Dc= 1.439 g/cm3, F（000） = 476 and/（MoKa） = 0.123 mm＂1. The final R = 0.0484 and wR = 0.1080 for 1776 observed reflections with 1〉 2r（/） and R = 0.0679 and wR = 0.1183 for all data. X-ray diffraction reveals that the （2D＋ID） hydrogen bonds pillar the structure into an open 3D supramolecular framework with a pore along the b axis （approximate dimensions 5.9＊10.5 /2）, which is occupied by free water molecules. Photolu- minescent investigation reveals that the title compound displays an emission in the blue region.     

Efficient Room‐Temperature Synthesis of Tri‐ and Tetrasubstituted Imidazoles Catalyzed by ZrCl4

A general protocol has been developed for the rapid synthesis of 2,4,5‐trisubstituted and 1,2,4,5‐tetrasubstituted imidazoles in high yields using ZrCl₄ as an efficient catalyst at room temperature. A variety of aromatic, aliphatic, and terpenoidal aldehydes underwent condensation with NH₄OAc/amines to give the imidazoles. Similarly, the imidazole glycoconjugates are prepared in good yields from the corresponding glycosyl aldehydes.     

Insights into the Mechanism of Extraction of Uranium (VI) from Nitric Acid Solution into an Ionic Liquid by using Tri‐n‐butyl phosphate

We present new results on the liquid–liquid extraction of uranium (VI) from a nitric acid aqueous phase into a tri‐n‐butyl phosphate/1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide (TBP/[C₄mim][Tf₂N]) phase. The individual solubilities of the ionic‐liquid ions in the upper part of the biphasic system are measured over the whole acidic range and as a function of the TBP concentration. New insights into the extraction mechanism are obtained through the in situ characterization of the extracted uranyl complexes by coupling UV/Vis and extended X‐ray absorption fine structure (EXAFS) spectroscopy. We propose a chemical model to explain uranium (VI) extraction that describes the data through a fit of the uranyl distribution ratio D_U. In this model, at low acid concentrations uranium (VI) is extracted as the cationic complex [UO₂(TBP)₂]²⁺, by an exchange with one proton and one C₄mim⁺. At high acid concentrations, the extraction proceeds through a cationic exchange between [UO₂(NO₃)(HNO₃)(TBP)₂]⁺ and one C₄mim⁺. As a consequence of this mechanism, the variation of D_U as a function of TBP concentration depends on the C₄mim⁺ concentration in the aqueous phase. This explains why noninteger values are often derived by analysis of D_U versus [TBP] plots to determine the number of TBP molecules involved in the extraction of uranyl in an ionic‐liquid phase.     

固体全氟烷基有机超酸的催化应用进展

全氟烷基超酸(磺酸RfSO3H,磺酰亚胺(RfSO2)2NH和磺酰基甲烷(RfSO2)3CH)比普通强酸(RSO3H等)表现出更强的酸性和更优秀的催化活性,固载化能提供高效的绿色催化途径.尤其无机载体SiO2负载固体酸,同时具备有机材料和无机材料的优点,比表面大、热稳定性好、酸位点有效、结构/织构可调可控.本文综述了上...     

Synthesis and cationic photopolymerization of 1-butenyl ether monomers

A new series of cationically polymerizable mono-, di- and multifunctional 1-butenyl ether monomers have been prepared in high yields by the ruthenium catalyzed isomerization of the corresponding crotyl (2-butenyl) ethers. Their straightforward synthesis and high reactivity in photoinitiated cationic polymerization make these monomers highly attractive for a variety of applications. Cationic polymerization rate studies showed that these monomers exhibited comparable reactivity to their related vinyl and 1-propenyl ether analogues. © 1995 John Wiley & Sons, Inc.