Design,Synthesis and in vitro Evaluation of a New Class of Novel Cyclooxygenase-2 Inhibitors:3,4-diaryl-3-pyrrolin-2-ones

COX-2 inhibitors as anti-inflammatory and analgesic agents that lack the gastro- intestinal damage and hematologic liabilities exhibited by currently marketed NSAIDs. This fact has led to the launching of two diarylheterocycle inhibitors, Celecoxib and Rofecoxib1-3. Celecoxib RofecoxibDesign and synthesis Common structures of most COX-2 inhibitors are characterized by the presence of two aryl rings in-cis position of a bridged hetercyclic ring, one of aromatic moiety being substituted by…     

Efficient Synthesis of α,β‐Epoxy Carbonyl Compounds in Acetonitrile: Darzens Condensation of Aromatic Aldehydes with Ethyl Chloroacetate

The Darzens reaction of ethyl 2‐chloroacetate ( 1 ) with aromatic aldehydes 2 in the presence of polymer‐supported or nonsupported quaternary ammonium salts proceeds under mild conditions by phase‐transfer catalysis to give the corresponding epoxides 3 in satisfactory yields (Tables 1 and 2). With both MeCN as solvent and polystyrene‐supported catalysts, diastereoselective Darzens reactions proceed in excellent yields and short times, with a fair degree of stereoinduction.     

N-乙烯基-2-吡咯烷酮-丙烯酸共聚物/聚乙二醇半互穿网络水凝胶的合成及其药物缓释性能

N-乙烯基-吡咯烷酮;释药;N-乙烯基-2-吡咯烷酮-丙烯酸共聚物/聚乙二醇半互穿网络水凝胶的合成及其药物缓释性能     

Enhanced photocatalytic H2 production over dual-cocatalyst-modified g-C3N4 heterojunctions

Ag nanoparticles (NPs) were deposited on the surface of g-C₃N₄ (CN) by an in situ calcination method. NiS was successfully loaded onto the composites by a hydrothermal method. The results showed that the 10 wt%-NiS/1.0 wt%-Ag/CN composite exhibits excellent photocatalytic H₂ generation performance under solar-light irradiation. An H₂ production rate of 9.728 mmol·g^?1·h^?1 was achieved, which is 10.82-, 3.45-, and 2.77-times higher than those of pure g-C₃N₄, 10 wt%-NiS/CN, and 1.0 wt%-Ag/CN composites, respectively. This enhanced photocatalytic H₂ generation can be ascribed to the co-decoration of Ag and NiS on the surface of g-C₃N₄, which efficiently improves light harvesting capacity, photogenerated charge carrier separation, and photocatalytic H₂ production kinetics. Thus, this study demonstrates an effective strategy for constructing excellent g-C₃N₄-related composite photocatalysts for H₂ production by using different co-catalysts.     

混合价双核锰配合物[(Phen)2Mn(μ-O)2Mn(Phen)2]ClO4)3CH2ClCOOH·2H2O的合成与表征

锰在某些生物的氧化还原活性部位起着重要的作用. 绿色植物光系统Ⅱ(PSⅡ)中的氧释放配合物(OEC)、含锰过氧化氢酶(Mn Catalase)、含锰超氧化物歧化酶(MnSOD)、含锰核糖核苷酸还原酶(Mn RR)等活性部位存在着双核或多核锰的配合物[1～3]. 因此, 模拟合成不同氧化态的、不同类型配体和不同核数锰的配合物, 研究其结构和光谱等性质, 对揭示生物体中锰酶的催化氧化还原过程将有重要意义. 混合价Mn(Ⅲ, Ⅳ)配合物的研究对于揭示PSⅡ中两分子H2O氧化为O2的机理具有重要意义[2,4]. 这类配合物的研究已有一些报道[5～10], 邻菲咯啉(Phen)作为配体形成的配合物[(Phen)2Mn\5(μ-O)2Mn(Phen)2](PF6)3*CH3CN的研究虽有报道[11], 但其晶体中两个锰离子配位环境几乎相同. 本文用新方法合成了双核锰配合物(该法容易得到单晶)并进行了表征.     

trans-[Ru(II)(dpp)Cl2]: a convenient reagent for the preparation of heteroleptic Ru(dpp) complexes, where dpp is 2,9-di(pyrid-2'-yl)-1,10-phenanthroline

The reaction of 2,9-di(pyrid-2'-yl)-1,10-phenanthroline (dpp) with [RuCl(3)·3H(2)O] or [Ru(DMSO)(4)Cl(2)] provides the reagent trans-[Ru(II)(dpp)Cl(2)] in yields of 98 and 89%, respectively. This reagent reacts with monodentate ligands L to replace the two axial chlorides, affording reasonable yields of a ruthenium(II) complex with dpp bound tetradentate in the equatorial plane. The photophysical and electrochemical properties of the tetradentate complexes are strongly influenced by the axial ligands with electron-donating character to stabilize the ruthenium(III) state, shifting the metal-to-ligand charge-transfer absorption to lower energy and decreasing the oxidation potential. When the precursor trans-[Ru(II)(dpp)Cl(2)] reacts with a bidentate (2,2'-bipyridine), tridentate (2,2';6,2'-terpyridine), or tetradentate (itself) ligand, a peripheral pyridine on dpp is displaced such that dpp binds as a tridentate. This situation is illustrated by an X-ray analysis of [Ru(dpp)(bpy)Cl](PF(6)).     

Self-consistent mean field approximation and application in three-flavor NJL model

In this study, we apply a self-consistent mean field approximation of the three-flavor Nambu–Jona-Lasinio(NJL) model and compare it with the two-flavor NJL model. The self-consistent mean field approximation introduces a new parameter, α, that cannot be fixed in advance by the mean field approach itself. Due to the lack of experimental data, the parameter, α, is undetermined. Hence, it is regarded as a free parameter and its influence on the chiral phase transition of strong interaction matter is studied based on this self-consistent mean field approximation. α affects numerous properties of the chiral phase transitions, such as the position of the phase transition point and the order of phase transition. Additionally, increasing α will decrease the number densities of different quarks and increase the chemical potential at which the number density of the strange quark is non-zero. Finally, we observed that α affects the equation of state(EOS) of the quark matter, and the sound velocity can be calculated to determine the stiffness of the EOS, which provides a good basis for studying the neutron star mass-radius relationship.     

Optimal control of a nonlinear parabolic–elliptic system

In this paper, we shall study the problem of optimal control of the parabolic–elliptic system

_ut+_(f(t,x,u))x+g(t,x,u)+_Px−_(a(t,x)ux)x=_f0+B^∗ν$u_t+{\left(f(t,x,u)\right)}_x+g(t,x,u)+P_x-{\left(a(t,x)u_x\right)}_x=f_0+B^{\ast }\nu$

Approach to High Open‐Circuit Voltage in Organic Solar Cells Utilizing a Structural Change of the Oxazolino‐C70 Derivative

Reactions of 2,5‐Bn₂C₇₀ (Bn=CH₂Ph) with hydroxide and ArCN (Ar=Ph, m‐ClPh) followed by quenching with I₂ and BnBr afforded dibenzylated and tetrabenzylated oxazolino[70]fullerenes, respectively. The latter has a novel structural configuration, in which the addends are positioned from the polar to the transequatorial region. A key structural feature of this compound is that the oxygen atom of the oxazoline ring is bound to the equatorial belt region of C₇₀, giving structural change in its reduced state. This enables stabilization of the reduced state, suppressing charge recombination dynamics in organic solar cells to give a high open‐circuit voltage (0.85, 0.93, and 1.11 V in devices using P3HT, PTB7, and DPP(TBFu)₂, respectively).