氟化氢的分析方法综述

简单介绍了氟化氢的性质,叙述了化学滴定法、比色法、氟离子选择电极法和离子色谱法等常用分析方法在氟化氢分析方面的应用原理及优缺点.对近年来发展起来的一些新的氟化氢分析方法如荧光分析法、发射光谱法、流动注射系统测氟法和傅立叶红外光谱法进行了阐述.     

(3,4),(8,9)-双环氧-内式-三环[5.2.1.02,6]癸烷在丙酮溶液中同氯化氢的开环反应

研究了(3,4),(8,9)-双环氧-内式-三环[5.2.1.0^2,6]癸烷及其外式异构体以及若干有关模型化合物在丙酮溶液中同氯化氢的开环反应,证明了其环戊烷环上的环氧基比双环[2.2.1]庚烷环上的环氧基具有较大的活泼性。     

REACTION OF THIOPHOSPHORYL FLUORIDE AND THIOPHOSPHORYL CHLORIDE WITH DIMETHYL SULPHOXIDE

Abstract

Solid complexes of thiophosphoryl fluoride and thiophosphoryl chloride with dimethyl sulphoxide (DMSO) have been prepared and characterized.     

离子色谱法测定磷酸氢钙中的氟化物

建立了离子色谱法测定磷酸氢钙中氟化物的方法。用本法测得的结果与化学法相符，相对标准偏差为0.65%-4.36%，回收率为99.5%-100.3%。     

硫氰酸汞分光光度法测定空气颗粒物中的氯化氢

用硫氰酸汞分光光度法分别测定空气及空气颗粒物和空气中氯化氢的含量,利用相减法得出空气颗粒物中氯化氢的含量。线性范围为0～1．00μg/mL,线性回归方程为A=0．0799c 0．00124,相关系数为0.9995。该方法灵敏、简便,测定结果的相对标准偏差为6．8％(n=7),加标回收率为98．1％～103．9％。     

离子色谱法测定米酒中F^—、Cl^—和SO4^2—

研究了用带电导检测器的离子色谱对米酒中F-、Cl-和SO24-进行分离测定的方法.在Dionex HPIC-AS3分离柱上用2.8mmol@L-1NaHCO3-2.2mmol@L-1Na2CO3作流动相进行洗脱,被测组分得到满意的分离,方法简便快速.F-、Cl-和SP24-线性范围分别为0.1～10、0.1～16和0.5～80mg@L～,检出限分别为0.1、0.1和0.5mg@L-1.该法也适用NO-3和NO-2测定.     

Small gas-phase dianions of Zn3O(4)(2-), Zn4O(5)(2-), CuZn2O(4)(2-), Si2GeO(6)(2-), Ti2O(5)(2-) and Ti3O(7)(2-)

We have searched for new species of small oxygen-containing gas-phase dianions produced in a secondary ion mass spectrometer by Cs+ ion bombardment of solid samples with simultaneous exposure of their surfaces to O2 gas. The targets were a pure zinc metal foil, a copper-contaminated zinc-based coin, two silicon-germanium samples (Si(1-x)Ge(x)(with x= 6.5% or 27%)) and a piece of titanium metal. The novel dianions Zn3O(4)(2-), Zn4O(5)(2-), CuZn2O(4)(2-), Si2GeO(6)(2-), Ti2O(5)(2-) and Ti3O(7)(2-) have been observed at half-integer m/z values in the negative ion mass spectra. The heptamer dianions Zn3O(4)(2-) and Ti2O(5)(2-) have been unambiguously identified by their isotopic abundances. Their flight times through the mass spectrometer are approximately 20 micros and approximately 17 micros, respectively. The geometrical structures of the two heptamer dianions Ti2O(5)(2-), and Zn3O(4)(2-) are investigated using ab initio methods, and the identified isomers are compared to those of the novel Ge2O(5)(2-) and the known Si2O(5)(2-) and Be3O(4)(2-) dianions.     

Photoelectron spectroscopy of fullerene dianions C76(2-), C78(2-), and C84(2-)

We report laser photoelectron spectra of the doubly negatively charged fullerenes C(76) (2-), C(78) (2-), and C(84) (2-) at 2.33, 3.49, and 4.66 eV photon energy. From these spectra, second electron affinities and vertical detachment energies, as well as estimates for the repulsive Coulomb barriers are obtained. These results are discussed in the context of electrostatic models. They reveal that fullerenes are similar to conducting spheres, with electronic properties scaling with their size. The experimental spectra are compared with the accessible excited states of the respective singly charged product ions calculated in the framework of time dependent density functional theory.     

离子色谱法测定化工工艺尾气中氯化氢

研究了离子色谱法测定化工工艺尾气中氯化氢。采用美国Dionex公司DX 100型离子色谱仪,以2.7mmol.L-1Na2CO3 0.3mmol·L-1NaHCO3作为淋洗液,流速为1.2ml·min-1,测定了化工工艺尾气中氯化氢。相对标准偏差为1.8%～2.0%,样品回收率为90%～98%。该方法简便、快速、准确度可靠。     

Infrared spectra and structures of the stable CuH(2)(-), AgH(2)(-), AuH(2)(-), and AuH(4)(-) anions and the AuH(2) molecule

Gold is noble, but excited gold is reactive. Reactions of laser-ablated copper, silver, and gold with H(2) in excess argon, neon, and pure hydrogen during condensation at 3.5 K give the MH molecules and the (H(2))MH complexes as major products and the MH(2)(-) and AuH(4)(-) anions as minor products. These new molecular anions are identified from matrix infrared spectra with isotopic substitution (HD, D(2), and H(2) + D(2)) and comparison to frequencies calculated by density functional theory. The stable linear MH(2)(-) anions are unique in that their corresponding neutral MH(2) molecules are higher in energy than M + H(2) and thus unstable to M + H(2) decomposition. Infrared spectra are observed for the bending modes of AuH(2), AuHD, and AuD(2) in solid H(2), HD, and D(2), respectively. The observation of square-planar AuH(4)(-) attests the stability of the higher Au(III) oxidation state for gold. The synthesis of CuH(2)(-) in solid compounds has potential for use in hydrogen storage.     

过氧化氢中微量氯离子、硝酸根、磷酸根、硫酸根的同时测定

在碱性条件下,过氧化氢加热回流分解,经阳离子树脂交换后,离子色谱法分析。以Na2CO3 NaHCO3 为淋洗液,分析柱为 IonPac AS14,抑制电导同时测定过氧化氢中微量 Cl-、NO-3 、PO3-4 、SO2-4 。消除了过氧化氢对分析柱的可能损害,使基线更加平滑,具有测试简便,分析周期短,准确性高的特点,检出限为0.01~0.03 mg·L-1,应用于过氧化氢中无机阴离子的测定。     

Carbon avoids hypercoordination in CB6(-), CB6(2-), and C2B5(-) planar carbon-boron clusters

The structures and bonding of CB6-, C2B5-, and CB62- are investigated by photoelectron spectroscopy and ab initio calculations. It is shown that the global minimum structures for these systems are distorted heptacyclic structures. The previously reported hexacyclic structures with a hypercoordinate central carbon atom are found to be significantly higher in energy and were not populated under current experimental conditions. The reasons why carbon avoids hypercoordination in these planar carbon-boron clusters are explained through detailed chemical-bonding analyses.