Intramolecular proton transfer induced by divalent alkali earth metal cation in the gas state

Interactions between divalent alkali earth metal (DAEM) ions M (M?Be, Mg, Ca, Sr, Ba) and the second stable glycine conformer in the gas phase, which can transfer into the ground‐state glycine‐M²⁺ (except the glycine–Be²⁺) among each corresponding isomers when these divalent metal ions are bound, are studied at the hybrid three‐parameter B3LYP level with three different basis sets. Proton transfers from the hydroxyl to the amino nitrogen of the glycine without energy barriers have been first observed in the gas phase in these glycine–M²⁺ systems. The interaction between the glycine and these DAEM ions except beryllium and magnesium ion only create an amino hydrogen pointing to the original hydroxyl due to their weaker interaction relative to those divalent transition metal (DTM) ion‐bound glycine derivatives, being obviously different from that between the glycine and DTM ions, in which two amino hydrogens point to the original hydroxyl oxygen when these metal‐chelated glycine derivatives are produced. The interaction energy between the glycine and divalent magnesium would be the boundary of one or two amino hydrogens pointing to the hydrogyl oxygen, i.e., the ?170.3 kcal/mol of binding energy is a critical point. Similar intramolecular proton transfer has also been predicted for those DTM ion‐chelated glycine systems; however, that in the gas state has not been observed in the monovalent metal ion‐coordinated glycine systems. The binding energy between some monovalent TM ion and the glycine is similar to that of the glycine–Ba²⁺, which has the lowest binding strength among these DAEM–ion chelated glycine complexes. The difference among them only lies in the larger electrostatic and polarized effects in the latter, which favor the stability of the zwitterionic glycine form in the gas phase. According to these observations, we predict that the zwitterionic glycine would exist in the field of two positive charges in the gas phase. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 205–214, 2003     

铋(Ⅲ)-8-羟基喹哪啶体系极谱行为——表面活性剂增敏机理和分析应用——Ⅱ.铋(Ⅲ)-8-羟基喹哪啶络合物电极反应和十二烷基苯磺酸钠增敏机理

试验表明,铋(Ⅲ)-8-羟基喹哪啶(8-OXQ)络合物(pHll,-0.60V)的峰电流(p)具吸附特性,为准可逆电极反应过程,其电子转移数(n),传递系数(α)及饱和吸附量(Γ_ο)分别为3,0.45,6.5×10~(-12) mol/cm~2。加入十二烷基苯磺酸钠(SDBS)未形成三元络合物,因SDBS的超载强烈吸附,引起诱导吸附,电双层结构激烈变化,而使电流峰形巨变,电流峰高(i_p)增大10余倍。讨论并指出SDBS对Bi(Ⅲ)与8-羟基喹啉(8-OX)及衍生物络合吸附电流增敏或抑制,与试剂组分、结构、解离态及络合物存在状态、电荷数、符号有关。     

8-羟基喹啉-硅胶介质的合成及其在海水中痕量铅检测的应用

详细研究了以大孔硅胶为基质,一步合成8羟-基喹啉(8-HQ)型金属螯合色谱填料的方法,采用正交试验对合成方法进行了优化。与传统合成方法所得的填料进行了比较,从理化指标等方面来看,新的合成方法为佳。将该法用作微柱流动注射(FIA)在线分离、富集和电感耦合等离子体质谱(ICP-MS)分析流程中的固定相,对大洋海水中的痕量铅进行了在线分析,得到了较满意的结果。     

一类新型多取代嘌呤类化合物的合成及生物活性

以4-氯-5硝基嘧啶(3)为起始物, 经胺解、还原和环合等反应, 构建了新型的多取代嘌呤-8-硫酮(6)结构. 通过化合物6与卤代物的反应, 获得了该杂环的8位巯基衍生物7a-1~7, 7b-1~5和8, 其结构经元素分析, 1H NMR, IR及MS确证. 生物活性测试结果表明,  化合物6和7具有一定的除草和抗烟草花叶病毒活性.     

Improved syntheses of some monochloro- and monobromo-8-quinolinols

Summary Procedures were developed for the preparation of the 2-, 3-, 4-, and 6-monosubstituted chloro and bromo 8-quinolinols which afforded greater yields and/or reduced the number of steps in the preparation. 100 MHz¹H-NMR spectra for the 12 possible monochloro and monobromo analogues are given.

---

Verbesserte Synthese von Monochlor- und Monobrom-8-chinolinolen

Zusammenfassung Es wurden Verfahren entwickelt, um 2-, 3-, 4- und 6-Chlor bzw. -Brom-8-chinolinole in besseren Ausbeuten und/oder bei reduzierter Anzahl von Synthesestufen herzustellen. Die¹H-NMR-Spektren der 12 möglichen Monochlor- und Monobromverbindungen werden angegeben.

     

三环[5,2,1,0~(2,6)]癸-3-烯-8,9-二羧酸二甲酯的合成

通过对双环戊二烯的选择性羰基化加成，高产率地合成了三环[5、2、1、02，6]癸-3烯-8，9-二羧酸二甲酯。得到了无色透明的片状晶体，产率为90％。     

一种基于形成杂多核配合物的荧光增敏效应的研究（Ⅱ）──钴（Ⅱ）－7－（8－羟基－3，6－二磺基萘偶氮）－8－羟基喹啉－5－磺酸－硼（Ⅲ）三元体系的荧光性质及其分析应用

一种基于形成杂多核配合物的荧光增敏效应的研究（Ⅱ）──钴（Ⅱ）－７－（８－羟基－３，６－二磺基萘偶氮）－８－羟基喹啉－５－磺酸－硼（Ⅲ）三元体系的荧光性质及其分析应用熊国华，刘虹，俞英，黄坚锋（九江师范专科学校化学系，九江，３３２０００）（江西大学实...     

纳米复合固体超强酸S_2O_8~(2-)/CoFe_2O_4催化合成癸二酸二乙酯

将硫酸钴、硫酸亚铁在NaOH溶液中与NaHCO3反应制得碱式碳酸盐前驱体 ,后者用 (NH4 ) 2 S2 O8浸渍、干燥 ,再经 5 0 0℃焙烧得到固体超强酸催化剂S2 O2 -8/CoFe2 O4 。产物经XRD、TEM、BET、TG DTA及化学法等检测 ,含硫量 4 5 2 % ,粒径为 4 2nm ,比表面积为 1 4 6m2 /g ,粒度均匀。催化剂的酸强度处于 -1 6 0 2和-1 4 5 2之间。以该固体酸为催化剂 ,由癸二酸和无水乙醇合成了癸二酸二乙酯。最佳反应条件为 :n(醇 )∶n(酸 ) =4 0∶1 0 ,癸二酸 0 1mol,催化剂 1 0 g ,反应时间 2 5h。在此反应条件下 ,酯化率可达 93 6%。     

2-〔2′-(6-溴-苯并噻唑)-偶氮〕-1,8-二羟基萘-3,6-二磺酸的合成及其与钛的显色反应

本文合成了一种新的革并座隆类显色试剂—2－［2′－（6－溴－苯并噻唑）－偶氮］－1，8－二羟基萘－3，6－二磺酸（简称Br－BTCA），并研究了其与钛的显色反应。在CTMAB存在下，钛与试剂形成稳定的络合物，其ε616=1．15×105L·mol－1·cm-1，组成为Ti（Ⅳ）：R：=1：2：钛浓度在0～0．5mg／L范围内符合比尔定律，该方法灵敏度高，选择性好，并用于铝合金及硅铁试样中微量钛的测定