Simultaneous determination of bromide and iodide ions by capillary isotachophoresis using quaternary ammonium salts

Bromide and iodide ions were determined simultaneously by capillary isotachophoresis using an aqueous electrolyte system; the separation principle was based on the ion-pairing equilibria between tetradecyldimethylbenzylammonium ion and these anions in the leading electrolyte. The interaction between iodide ion and tetradecyldimethylbenzylammonium ion was stronger than that for bromide ion. Thus complete separation of bromide and iodide ions could be obtained by using a leading electrolyte containing 1.5 mM tetradecyldimethylbenzylammonium ion. The pH of the leading electrolyte was adjusted to 5.0. The relative standard deviations of the zone length for bromide and iodide ions were 1.1 and 1.2%, respectively, when mixture of 3.0 mM of these ions was analysed. A 150-μl volume could be injected for the simultaneous determination of low concentrations of bromide and iodide ions.     

A Polymeric Iodiplumbate(Ⅱ) Templated by Conjugated Quaternary Ammonium: Synthesis, Band Structure and Optical Properties

A new lead(Ⅱ) iodide coordination polymer [(npq)(PbI3)]n 1 (npq = N-propyl- quinolinium) has been synthesized in the presence of npq as structure-directing reagent (SDA). Compound 1 crystallizes in the orthorhombic system, space group Pbca, with a = 19.158(4), b = 7.9909(16), c = 22.929(5) (A), V = 3510.2(12) (A)3, Z = 8, Dc = 2.877 g/cm3, F(000) = 2672, C12H14I3NPb, Mr = 760.14, μ(MoKα) = 14.872 mm-1, the final R = 0.0431 and wR = 0.1021 for 3678 observed reflections with I＞2σ(I). Structure determination indicates that the [PbI3]-n infinite chains in each unit cell shape the sketch of 1, which could be described as the result of face-sharing distorted PbI6 octahedra running along the b axis. Electrostatic interaction between conjugated organic counter-cations and inorganic moieties presents and contributes to the crystal packing. 1 was further characterized with IR and elemental analysis. Based on the crystal structure data, quantum chemical calculation with DFT method was used to reveal the electronic structure and optical property of 1.     

合肥地区第四纪孢粉组合及古植被、古气候研究

本文孢粉组合是从合肥地区城建施工单位工程钻孔中获得。根据,木本、草本、和蕨类植物在钻孔剖面中的变化规律,分两个孢粉组合带。 第一组合带,木本植物占17.62％,乔木层中的落叶阔叶层片以栎、榆、桦为主要树种,针叶层片中以松属,油杉属为优势树种,蕨类植物与草本植物计占15—70％,以蕨类中的卷柏,紫萁,水龙骨及草本类的禾本科,菊科,蒿属,十字花科为草木本层中的主要成分,低洼的地沼水域中繁殖大量环纹藻。 第二组合带的第一亚组合,木本植物的属种明显下降,其含量则上升为38—94％乔木层非常单调,松属几乎独占了贫脊的山岗坡地,蕨类植物踪迹稀少,禾本科、毛莨科、蒿属,豆科等草本层散生于河谷岸边及低矮的坡地。 第二亚组合,木本植物占27—56％,乔木层中:针叶层片内以松属,油杉属为建群主要树种,落叶阔叶层片只占3.3—9.0％,栎、柳、胡桃、枫杨、榆、漆树等均有一定含量。蕨类和草本植物占2.5—14 5％,蕨类植物类型较少,水龙骨为植被中的常见物种,草本类以禾本科,毛莨科,蒿属为主,其它属种出现不多,这个阶段草本层仍不大兴旺。 以上两个组合带中末发现冷杉,云杉的踪影,桦属含量极低,植被反映为温湿或温凉的气候,因此两个组合不可能为晚冰期,其地层时代应晚于晚更新世,这样可确认合肥地区为全新世晚期,     

季铵盐胶束的制备及其抗菌性能研究

为了研究季铵盐胶束是以胶束的形式抗菌还是以胶束解体后的单体形式与细胞膜结合达到抗菌效果,制备了一种季铵盐表面活性剂,该表面活性剂可以自组装成非交联胶束,还可以通过含有酯键的交联剂获得表面交联胶束.交联胶束在脂肪酶的作用下能解交联形成解交联胶束.利用核磁共振氢谱和动态光散射对合成的表面活性剂进行了分析,通过最低抑菌浓度和透射电子显微镜探讨了胶束的抗菌性能.     

Structural and optical properties of quaternary AlInGaN epilayers grown by MOCVD with various TMGa flows

AlInGaN quaternary epilayers have been grown with various TMGa flows by metalorganic chemical vapor deposition to investigate the influence of growth rate on the structural and optical properties. Triple-axis X-ray diffraction measurements show AlInGaN epilayers have good crystalline quality. Photoluminescence (PL) measurements show that the emission intensity of AlInGaN epilayers is twenty times stronger than that of AlGaN epilayer with comparable Al content. V-shaped pits are observed at the surface of AlInGaN epilayers by atomic force microscopy (AFM) and transmission electron microscopy (TEM). High growth rate leads to increased density and size of V-shaped pits, but crystalline quality is not degraded.     

Synthesis of Chiral Ionic Polymers Containing Quaternary Ammonium Sulfonate Structure and their Catalytic Activity in Asymmetric Alkylation

Repeated reaction between chiral quaternary ammonium dimer and disodium disulfonate gave the ionic polymer, which contains chiral quaternary ammonium sulfonate structure as a repeating unit. This chiral ionic polymer showed an excellent catalytic activity in asymmetric alkylation reaction. With the chiral ionic polymer catalysts, high level of enantioselectivities up to 97% ee were attained.     

壳聚糖季铵盐/滤纸复合膜对胆红素的吸附研究

用2,3-环氧丙基三甲基氯化铵对壳聚糖进行化学修饰,在壳聚糖的分子结构中引入季胺盐基团,提高其阳离子含量。将壳聚糖季铵盐涂在滤纸上,用戊二醛交联,制得壳聚糖季铵盐/滤纸复合膜,考察该复合膜的强度以及对胆红素的吸附性能。实验结果表明,壳聚糖季铵盐/滤纸复合膜具有良好的力学性能;对胆红素的吸附在3h基本达到平衡,其吸附量远大于壳聚糖/滤纸复合膜;适当取代度及高交联度的复合膜吸附效果较好。复合膜对胆红素的吸附量随离子强度的增加而降低;血清白蛋白的加入使吸附量下降。     

Synthesis and Characterization of Quaternary Complexes Ln ( CH2 ClCO0 ) 2 ( NO3 ) ( phen)

Many trinary lanthanide complexes have been studied. However, few mixed anion complexes with bidentate heterocyclic amines were synthesized. We synthesized mixed anion complexes Ln ( CHi CICO0 )2 (NO3) (phen) which was determined by elemental analyses. The IR spectra analyses indicate that NO3 ,CH2 C1CO0- and phen are coordinated with Ln. The molar conductances of the complexes at 10-3 mol. L-1 were founded to be between 32.4 and 35.8 S. cma@mol- 1 , suggesting the nonelectrolytes in N Dimethylformamide. And we determined the fluorescent spectra Eu(CH2C1COO)2(NO3) ( phen ) and ESR spectra of Gd( CH2 ClC00 )2 ( NOs ) ( phen ) .     

A facile construction of the tricyclic 5-7-6 scaffold of fungi-derived diterpenoids. The first total synthesis of (±)-heptemerone G and a new approach to Danishefsky’s intermediate for a guanacastepene A synthesis

The first total synthesis of (±)-heptemerone G, a diterpenoid metabolite of a submerged culture Coprinus heptemerus, and a new approach to an advanced intermediate for a synthesis of guanacastepene A are reported.     

青藏高原腹地第四纪地质环境演化的地球动力学机制

根据古季风变化与生物生产总量之间的耦合关系，结合区域地质演变和地球卫星遥感影像解译成果，对引起高原内部古气候环境变化发展过程的启动激发因素和相互耦合机制及其驱动传递效应进行探索研究，这个方向目前仍然属于高原地质环境演变及全球变化的前沿领域。