EPR of 3d 5 and 3d 8 Ions in Crystals With Perchlorate Structure at High Pressure

EPR spectra for ions Ni 2+ (3d 5 ) and Mn 2+ (3d 5 ) substituting Zn 2+ in crystals Zn(BF 4 ) 2 ·6H 2 O are studied within a wide range under hydrostatic pressure in X and Q bands. It is shown that the pressure changes to a considerable extent the spectrum parameters of ion Mn 2+ , reducing axial parameter b_{2}^{0} and increasing cubic one b_{4}^{0} at 9 kbar pressure, there is no temperature dependency of parameter b_{2}^{0} . Hydrostatic pressure changes linearly the initial splitting of ion Ni 2+ and results to a change in D(b_{2}^{0}) sign, which means the spin levels inversion at 3.5 kbar.     

Der UCl3‐Typ mit komplexen Anionen und seine Additions‐Substitutions‐Variante: Synthese und Kristallstruktur von Nd(ClO4)3 und Na0, 75Nd0, 75(ReO4)3

The UCl₃ Type of Structure with Complex Anions and its Addition‐Substitution Variant: Syntheses and Crystal Structure of Nd(ClO₄)₃ and Na_{0, 75}Nd_{0, 75}(ReO₄)₃ Pale violet single crystals of Nd(ClO₄)₃ (hexagonal, P6₃/m, Z = 2, a = 933.0(1), c = 560.08(5) pm, R_all = 0.0422) were obtained by careful dehydration of Nd(ClO₄)₃·6H₂O under flowing argon at 220 °C. Hexagonal single crystals of Na_{0, 75}Nd_{0, 75}(ReO₄)₃ (P6₃/m, Z = 2, a = 1000.0(1), c = 636.08(5) pm, R_all = 0.0206) show the same colour and are formed in the reaction of Nd(ReO₄)₃ with excess NaCl at 820 °C. Single phase powder samples can be obtained by a solid state reaction of NaReO₄ and Nd(ReO₄)₃ in evacuated silica tubes at elevated temperatures.     

Extraction of Perchlorate and Iodide by Ion-Pair Formation with the Iron(II)-di(2-Pyridyl)N,N-DI[(8-quinolyl)amino]methane Complex

Abstract

Di(2-pyridyl)N, N-di[(8-quinolyl)amino]methane (DPQAM) was used for the substoichiometric extraction and photometric determination of perchlorate and iodide in the ranges 10–1000 and 50–1000 ppm, respectively, by extraction of the Fe(DPQAM)₂X₂ (X = C1O₄ ^? or I^?) into chloroform. The determination ranges were found to be dependent on the Fe(II) concentration used.     

A New Sensor for Perchlorate Ion

Abstract

A potentiometric sensor for perchlorate anion was developed by mixing a silica gel, chemically modified with 1,4-diazabicyclo (2.2.2) octane, with an epoxy polymer and carbon. The electode showed Nernstian response to the perchlorate ion in the concentration range of 10^?1 and 10^?4 mol L^?1.     

Ln2(ClO4)2(H2I2O10) · 8H2O (Ln = Sm,Gd), a Lanthanide Perchlorate Mesodiperiodate forming a Novel Layer Structure

By slow evaporation of solutions containing Ln(ClO₄)₃ (Ln = Sm, Gd), H₅IO₆ and an excess of HClO₄, crystals of the title compounds could be obtained. Their structures were determined by single‐crystal X‐ray diffraction. The compounds crystallize in the monoclinic crystal system, space group P2₁/c. They contain Ln³⁺ ions, which are coordinated by [H₂I₂O₁₀]^4— anions forming two‐dimensional, cationic networks. These are separated by perchlorate ions, forming a layered structure.     

改进的离子色谱法测定环境水样中的高氯酸盐

以亲水性阴离子交换柱IonPac AS16为分析柱, 以NaOH、乙腈和水的混合溶液为淋洗液, 采用电导检测法测定了环境水样中的痕量高氯酸盐. 通过添加有机改进剂有效地解决了4-氯苯磺酸和高氯酸盐共淋洗的问题. 实验考察了4种有机溶剂对高氯酸盐和4-氯苯磺酸保留时间的影响, 最终选定乙腈作为有机改进剂. 为了提高方法的灵敏度, 以AG19为浓缩柱对样品进行在线预浓缩. 采用预浓缩技术可使方法的检出限低至0.1 μg/L. 在0.2~200 μg/L线性范围内线性相关系数为0.9989, 将0.5 μg/L 高氯酸盐溶液连续进样测定11次, 所得峰面积的相对标准偏差(RSD)为4.2%. 将该方法应用于环境水样的测定, 加标回收率为93%~113%.     

离子色谱-质谱联用测定牛奶中的高氯酸盐、溴酸盐和碘离子

以离子色谱-质谱联用同时测定了不同品牌牛奶中的高氯酸盐、溴酸盐和碘离子。以高容量、强亲水性IonPac AS20(2 mm)为分析柱,EGC在线产生KOH为淋洗液,串联质谱检测。ESIMS/MS以多元反应监测(MRM)模式分别监控高氯酸盐的m/z100.8/84.9、98.8/82.9离子对,溴酸盐的m/z126.8/110.9、126.8/95.0离子对和碘离子的m/z126.8/127.0离子对,并分别对高氯酸盐、溴酸盐和碘离子以m/z98.8/82.9、126.8/110.9和126.8/127.0离子对的峰面积进行定量。该方法对高氯酸盐、溴酸盐和碘离子的检出限(S/N=3)分别为0.02、0.1和0.5μg/L,线性相关系数分别是0.999(0.05~50μg/L)、0.999(0.5~100μg/L)、0.998(1~1 000μg/L)。高氯酸盐和碘离子的样品加标回收率分别在102%~108%之间和86%~114%之间。     

Striking selectivity of anion incorporation into polypyrrole by competitive doping: perchlorate versus hexafluorophosphate

In the electro-oxidative preparation of polypyrrole films from electrolyte media containing both perchlorate and hexafluorophosphate anions a striking selectivity towards ClO₄ was observed, with a three-fold preference for this anion in films from aqueous medium and a greater than ten-fold preference from MeCN. This result is of benefit towards the production of polypyrroles containing complex functionalized dopant anions, since the presence of PF₆ to bolster electrolysis parameters will less readily carry over into the final polymer. PF₆ is particularly useful for this purpose in MeCN, where ClO₄ is inappropriate, being itself too readily incorporated into the polymer from this solvent system.     

Three Modifications of [Pr2(ClO4)2(H2I2O10)]·8 H2O — A Theme with Variations

From solutions containing praseodymium perchlorate and periodic acid, three different modifications of [Pr₂(ClO₄)₂(H₂I₂O₁₀)] · 8 H₂O could be obtained. All of them crystallize in the monoclinic system, space group P2₁/c (α: a = 1091.47(6), b = 728.24(4), c = 1388.84(8) pm, β = 101.420(3)°; β: a = 1169.93(3), b = 728.72(2), c = 1384.50(4) pm, β = 112.303(2)°; γ: a = 1209.56(4), b = 712.53(2), c = 1361.64(5) pm, β = 115.691(1)°). The structures contain Pr³⁺ cations which are coordinated by [H₂I₂O₁₀]^4— anions yielding two‐dimensional networks. These networks are separated by ClO₄^— anions yielding a layered structure.     

Crystal Structure of the Bis[zinc(II)-hydroxide-(μ-perchlorate)-triaqua] Complex

Colorless single crystals of the title compound were accidentally obtained by a reaction of p-sulfophenylalanine with zinc perchlorate. The crystal structure (monoclinic, P2₁/c, Z = 4, a = 5.9031(7), b = 13.5404(16), c = 9.7932(8) Å, β = 126.438(5)°, V = 629.74(12) ų, R₁[I>2σ(I)] = 0.0276, wR₂(all) = 0.0844) reveals a discrete dinuclear [Zn(OH)(μ-ClO₄)(H₂O)₃]₂ in which each perchlorate anion acts as a bidentate bridging linker to bind two Zn atoms whereas the hydroxy group is a terminal group. Thus, the local surrounding around the zinc atom can be best described as a slightly distorted octahedron.