Design and synthesis of novel type VI-like β-turn mimetics. Diversity at the i+1 and the i+2 position

In this paper, a synthetic approach for functionalised 5-aminopiperidinone-2-carboxylate (APC) systems as non-pro cis-peptide bond containing external β-turn mimics is presented. The scope and limitations of the synthetic method are discussed and the potential turn inducing properties of a model compound are evaluated by means of molecular modelling and NMR analysis.     

Ag2S基近红外II区荧光量子点的水相合成优化探究

具有近红外II区荧光的Ag₂S量子点(QDs)因具有带隙窄、Stokes位移大及光稳定性好等优点而在生物成像领域具有广阔应用前景. 然而, 传统有机相合成的Ag₂S量子点水溶性与生物相容性较差, 而水相合成Ag₂S量子点的荧光又很难到近红外II区, 这严重制约了Ag₂S量子点的生物医学应用推广. 因此, 优化探究具有近红外II区荧光发射的Ag₂S基量子点的水相合成方法具有重要意义. 采用核掺杂ZnS、表面阳离子(Zn²⁺)改性以及调控表面配体制备出一系列Ag₂S基量子点, 发现核掺杂和表面阳离子改性均使Ag₂S基量子点的荧光呈现剂量依赖性蓝移; 而将表面配体由树枝状短链(Captopril)更换为长直链(11-巯基十一烷酸, MUA)时, Ag₂S基量子点的发射峰红移至1105 nm(近红外II区)且半峰宽更窄. 本研究发现, 相比核掺杂和表面阳离子改性, 优化表面配体更容易在水相中制备出具有近红外II区荧光的Ag₂S基量子点. 本工作为近红外荧光量子点的水相合成及优化提供了基础研究数据.     

基于3，3′，5，5′-四咪唑基联苯配体的Zn(II)金属有机骨架及其吸附性能

选用刚性3,3'',5,5''-四咪唑基联苯(L)作为主配体,分别辅以4,4''-联苯二羧酸(4,4''-H₂BPDC)和4,4''-氧二苯甲酸(H₂OBA)为第二配体,在水热条件下,成功制备了 2种基于 Zn(II)的金属有机骨架,即[Zn₂(L)(BPDC)₂]·H₂O (1)和[Zn₂(L)(OBA)₂]·6H₂O (2)。单晶X射线衍射表征结构显示：1和2均为(4,4)-连接的二节点的双重贯穿的新型3D孔道结构,其中2具有一定的孔隙率。活化的2(2'')的吸附性质表明其对H₂O和EtOH具有选择性吸附。     

4-羟基-3-(2-亚氨基乙基)-2H-苯并吡喃-2-酮类化合物的超声辐射合成

以乙醇为溶剂,4-羟基-3-乙酰基香豆素和胺为原料,对甲苯磺酸为催化剂,在超声波作用下合成一系列4-羟基-3-(2-亚氨基乙基)-2H-苯并吡喃-2-酮类化合物,产率62%~94%。 对产物进行了IR、1H NMR及HRMS表征,对化合物3c进行了X射线衍射分析。 该方法具有反应产率高、时间短、反应条件温和及操作简单等优点。     

反相高效相色谱法测定杜香嫩枝叶中的熊果酸

杜香（Ledum palustre L.）是杜鹃花科杜香属常绿小灌木,其挥发油具有明显的镇咳、祛痰作用,对皮肤瘙痒和脚气等有较好的疗效,因而受到广大研究者的关注。我们在研究杜香指纹图谱时发现杜香含有活性化合物熊果酸,其对应色谱峰与熊果酸对照品的保留时间及吸收谱图基本一致,峰纯度良好。本文报道了杜香中熊果酸的反相高效液相色谱（RP-HPLC）测定方法,方法准确、简便,能排除杂质干扰,重复性好。     

1．4──二氢吡啶类钙拮抗剂的合成法研究Ⅲ非洛地平的合成

在无水氯化锌的存在下，２，３－二氯苯甲醛与乙酰乙酸甲酯经Ｋｎｏｅｖｅｎａｇｅｌ－Ｄｏｅｂｎｅｒ缩合反应，制成２，３－二氯亚苄基乙酰乙酸甲酯（２），继而与３－氨基丁烯酸甲酯在阳离子交换树脂Ｄ６１的催化下进行环合Ｍｉｃｈａｅｌ加成反应，得非洛地平（１），以２，３－二氯苯甲醛计算，总收率７６．５％。探计了无水氯化锌的用量，反应温度对２收率的影响，还考察了不同阳离子交换成树脂对１的收率和质量的影响。     

Fabrication of monodispersed nickel flower-like architectures via a solvent-thermal process and analysis of their magnetic and electromagnetic properties

Monodispersed Ni flower-like architectures with size of 1–2 μm were synthesized through a facile solvent-thermal process in 1,2-propanediol solution in the presence of polyethylene glycol (PEG) and sodium alkali for electromagnetic absorption application. The Ni architectures are composed of nanoflakes, which assemble to form three dimensional flower-like structure, and the thickness of nanoflakes is about 10–40 nm. A possible formation mechanism for Ni flower-like architectures was proposed and it was confirmed by the control experiments. The Ni architectures exhibited a saturation magnetization (M_s) of 47.7 emu/g and a large coercivity (H_cj) of 332.3 Oe. The epoxy resin composites with 20 vol% Ni sample provided good electromagnetic wave absorption performance (reflection loss <−20 dB) in the range of 2.8–6.3 GHz over absorber thickness of 2.6–5.0 mm.     

Rhenium(IV)–copper(II) heterobimetallic complexes: Synthesis,crystal structure and magnetic properties

Two Re(IV)–Cu(II) heterometallic complexes {(CuL_α)[ReCl₄(ox)]}_n (where L_α = N-meso-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄), 1, and (CuL_β)[ReCl₄(ox)] (L_β = N-rac-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄N-rac-5,12-Me₂-7,14-Et₂-[14]-4,11-dieneN₄), 2, were synthesized. The [CuL²⁺] macrocyclic cation is coordinated from above and below by [ReCl₄(ox)]²⁻ units through the chloro-ligands and creates a chloro-bridged heterometallic Re^IV–Cu^II one-dimensional zig-zag chain. Compound 2 can be viewed as a heterobimetallic dinuclear unit, in which the Re(IV)-Cu(II) centers are linked by an oxalato bridge. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.8–300 K. Compound 1 behaves like a ferrimagnetic {Re(IV)–Cu(II)} bimetallic, one-dimensional chain with intrachain antiferromagnetic coupling. Compound 2 shows a weak antiferromagnetic interaction within the [Re(IV)–Cu(II)] unit along with a strong single-ion anisotropy, D(Re) = −63 cm⁻¹.