星形低分子量块状化合物的合成

近来对由不相容部分构成的块状共聚物的研究表明,通过改变各块的对比度(刚性与柔性,亲水性与亲油性,极性与非极性等)或改变各块的相对体积比, 均可改变这类物质的自组装行为获得新的液晶相态[1a].     

A New Cationic Fluorescent Probe for HSO3− Based on Bisulfite Induced Aggregation Self-Assembly

In comparison with the numerous studies that have centered on developing molecular frameworks for the functionalization of fluorescent materials, less research has addressed the influence of the side chains, despite such appendages contributing significantly to the properties and applications of fluorescent materials. In this work, a new series of cationic fluorescent probes with AIE characteristics have been developed, which exhibit unique sensitivity for charge-diffusion anions, namely HSO₃⁻, via the interactions of ions and the cooperation of the controllable hydrophobicity. The impact of the alkyl chain length attached at the cationic probes suggested that the fluorescent intensity and sensitivity of the probes could be partially enhanced by adjusting their aggregation tendency through the action of the hydrophobic effect under aqueous conditions. DLS and SEM images indicated that different particle sizes and new morphologies of the probes were formed in the anion-recognition-triggered self-assembly process, which could be attributed to the composite effect of electrostatic actions, Van der Waals forces and π-π stacking.     

Synthesis and Crystal Structure of a Vanadium(Ⅴ) Complex with 2-Hydroxy-1-naphthaldehyde Isonicotinoyl Hydrazone

The mononuclear vanadium(Ⅴ) complex with 2-hydroxyl-1-naphthaldehyde isoncotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction.The crystal is of monoclinic,space group P2 1/n with a = 10.3153(15),b = 7.4024(11 ),c = 24.413(4) (A),β= 101.911(2)°,V= 1824.0(5) (A)3,Z = 4,Mr = 427.28,Dc = 1.556 g/cm3,F(000) = 880,μ(MoKα) =0.591,the final R = 0.0372 and wR = 0.0926.The vanadium(Ⅴ) atom adopts a distorted square-pyramidal geometry coordinated by the tridentate ligand and two oxygen atoms.The hydrogen bonds and strong π…π stacking interactions link the complex molecules into a 3-D network structure.     

The synergistic catalysis on Co nanoparticles and CoN_x sites of aniline-modified ZIF derived Co@NCs for oxidative esterification of HMF

An efficient sustainable and scalable strategy for the synthesis of porous cobalt/nitrogen co-doped carbons(Co@NCs) via pyrolysis of aniline-modified ZIFs,has been demonstrated.Aniline can coordinate and absorb on the surface of ZIF(ZIF-CoZn3-PhA),accelerate the precipitation of ZIFs,thus resulting in smaller ZIF particle size.Meanwhile,the aniline on the surface of ZIF-CoZn3-PhA promotes the formation of the protective carbon shell and smaller Co nanoparticles,and increases nitrogen content of the catalyst.Because of these prope rties of Co@NC-PhA-3,the oxidative esterification of 5-hydroxymethylfurfural can be carried out under ambient conditions.According to our experimental and computational results,a synergistic catalytic effect between CoN_x sites and Co nanoparticles has been established,in which both Co nanoparticles and CoN_x can activate O_2 while Co nanoparticles bind and oxidize HMF.Moreover,the formation and release of active oxygen species in CoN_x sites are reinfo rced by the electronic interaction between Co nanoparticles and CoN_x.     

固相萃取/液相色谱-串联质谱法测定水果蔬菜中双胍辛胺的残留量

建立了测定沃柑、菠萝蜜、苹果、葡萄、生菜、黄瓜、西红柿、芦笋等水果蔬菜中双胍辛胺残留量的固相萃取/液相色谱-串联质谱方法。试样用0.2%乙酸水提取,二氯甲烷萃取杂质,提取液经WCX固相萃取柱净化,10%甲酸乙腈洗脱,氮吹至近干后以0.2%甲酸水复溶。采用甲醇和0.2%甲酸水为流动相,经Eclipse Plus C18(2.1 mm×100 mm,1.8μm)分离,在电喷雾离子源正离子模式下采用双胍辛胺的双电荷加合母离子m/z 178.8及其子离子m/z 100.0和187.0进行多反应监测（MRM）扫描,基质加标曲线进行定量。结果表明,双胍辛胺在0.005～0.160 mg/kg范围内线性关系良好,相关系数r≥0.995;0.010、0.020、0.050 mg/kg加标水平下的平均回收率为88.5%～109%,相对标准偏差（RSD,n=6）为2.1%～8.8%;方法检出限为0.005 mg/kg,定量下限为0.010 mg/kg。该方法快速、准确、灵敏,适用于水果蔬菜中双胍辛胺残留量的测定。     

重要传感材料荧光共轭聚合物PPESO3的一种新的简便合成路线

本文提出了一种新的简便得多的合成路线, 既避免了BBr3的使用, 又简化了反应步骤, 使PPESO3的合成简单易行, 为更广泛地对其进行研究与应用提供了便利条件. 此外, 本文还研究了PPESO3与非离子表面活性剂(聚乙烯吡咯烷酮, PVP)之间的相互作用, 结果表明, PVP与PPESO3形成了稳定的络合体, 可以有效地打破聚合物在水溶液中的聚集, 提高荧光量子产率.     

PVCH-PE-PVCH三嵌段共聚物在超临界CO2中的熔融再结晶行为

本研究组在前期研究中发现, 改变溶剂的挥发速率可以调节体系中PE结晶和PVCH玻璃化之间的竞争, 进而调节PE结晶的受限程度. 超临界二氧化碳(scCO2)是一种非极性溶剂, 其对无定形聚合物(如PS)有很强的溶胀作用, 可显著降低聚合物的玻璃化转变温度, 提高原来被冻结的高分子链的活动能力. PVCH的分子结构与PS相似, 研究结果表明, scCO2对PVCH组分也有很强的溶胀能力, 导致PVCH的玻璃化转变温度降低, 从而可以改变PE嵌段的受限状态. 本文研究了PVCH-PE-PVCH在scCO2中的熔融再结晶行为.     

Synthesis and Bioactivity of Novel Fluorinated Heteroaromatic Ureas

In order to find new urea cytokinins, a series of novel fluorinated heteroaromatic ureas have been designed and synthesized. The crystal structure of 3g was further determined by single crystal X-ray diffraction to obtain the structural feature of this class of urea compounds. The preliminary bioassay showed that some title compounds have good cytokinin activity.     

维生素E的不对称合成

系统地综述了维生素E的合成方法, 旨在为进行维生素E及其相关萜类化合物合成的研究人员提供参考.     

冀北滦平地区中生代火山岩中单颗粒锆石的稀土元素特征及启示

通过对滦平地区中生代火山岩中锆石的稀土元素分析,表明髫髻山组顶部火山岩样品中锆石δEu的均值为0.49,（Lu/Gd）N的均值为21.87;然而,土城子组顶部层位、底部层位和张家口组底部层位火山岩样品中锆石的δEu均值分别为0.15,0.06和0.09,（Lu/Gd）N的均值分别为14.51,15.66和16.25.反映了土城子组中锆石的稀土元素特征与张家口组中锆石特征的一致性,而与髫髻山组中的锆石有较大的区别,表明土城子组与张家口组中的火山岩有明显的亲缘性和一致性.结合同位素测年结果和锆石的阴极发光特征,可以认为： 该地区的髫髻山组与土城子组之间不仅时间间隔长,而且火山岩的源区也有较大的区别;土城子组与张家口组之间不仅在时间上基本连续,而且火山岩的源区也有明显的一致性;该分析结果暗示了滦平地区的土城子组与张家口组之间不存在时间的间断和大的构造界面,是相同（或相近）地质背景下形成的,即二者之间应不存在构造转换界面和J3-K1界面.研究表明,在壳源岩浆锆石的稀土元素分析中,（Lu/Gd）N,δEu是相对稳定的、有指示意义的两个重要参数;壳源岩浆锆石的∑LREE的值变化范围较大,尤其是La的丰度变化范围较大,所以在锆石的稀土元素分析中,与La相关的各种比值的指示意义并不明显.