Crystal structure of N‐(3,4‐dichlorophenyl)‐N′‐hydroxy‐2‐oxo‐2‐phenylacetamidine

The title compound (C₁₄H₁₀N₂O₂Cl₂) crystallizes in the monoclinic space group P2₁/a with a=10.042(1) Å, b=10.317(1) Å, c=13.877(2) Å, β=97.36(2)°, V=1425.8(3) ų, Z=4, D_x=1.44 g.cm^‐3. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R = 0.0457). The title molecule consists of 3,4‐dichlorophenylamino and 2‐phenyl‐1,2‐ethanedione‐1‐oxime groups. The intermolecular O‐H…N and N‐H…O hydrogen bonds [O…N 2.760(6) and 3.087(5) Å] are highly effective in forming the polymeric chains. The oxime group has an E configuration. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples

The radiometric methods, alpha (α)-, beta (β)-, gamma (γ)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches, these radionuclides include ³H, ¹⁴C, ³⁶Cl, ⁴¹Ca, ^59,63Ni, ^89,90Sr, ⁹⁹Tc, ¹²⁹I, ^135,137Cs, ²¹⁰Pb, ^226,228Ra, ²³⁷Np, ²⁴¹Am, and isotopes of thorium, uranium and plutonium. The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed.     

紫外分光光度法测定乙二醛含量的研究

首次报道利用醛基的成肟反应以及乙二醛二肟对紫外光的特征吸收，用紫外分光光度法测定乙二醛的含量。试验表明，在８．２×１０＾－６－５．９×１０＾－５ｍｏｌ／Ｌ浓度范围内，乙二醛溶液遵守Ｂｅｅｒ定律；方法的平均回收率为１００．７％（ｎ＝９，ＲＳＤ＝１．１％），具有简便，快速等优点。可供乙二醇氧化制备乙二醛研究中测定乙二醛产率用，也可用于乙二醛产品纯度的测定。     

丁二酮肟复合铋膜修饰电极测定痕量铅

目的：通过探讨缓冲溶液、 pH、丁二酮肟和镀铋液浓度、富集时间、富集电位对方波溶出伏安法测铅的影响,建立了一种快速测定水样痕量铅的新方法。方法采用丁二酮肟复合同位镀铋膜修饰铂电极,用方波溶出伏安法对水样中痕量铅进行测定。结果在优化的实验条件下,2.0＆#215;10-8～1.0＆#215;10-5 mol/L范围内Pb2＋峰电流与浓度呈良好的线性关系（ r≥0.9963）,富集时间为240 s时, Pb2＋的检出限为2＆#215;10-9 mol/L。结论该法操作简便、灵敏度高、检测限低,且样品经简单消解后即可直接用于测定,无需复杂的富集分离过程。与石墨炉原子吸收法比较,结果一致性较好,效果满意。     

Spectrophotometric Determination of Copper in Natural Waters and Pharmaceutical Samples with Chloro(Phenyl) Glyoxime

A simple method for the determination of trace amounts of copper by spectrophotometry is described based on the formation of the copper‐chloro‐(phenyl) glyoxime complex. The molar absorptivities of the complexes at pH 4.0 at 290.5 nm were 0.8 × 10⁴l/mol cm. Optimal conditions such as reagent amounts and pH for the copper determination were reported. The effects of the foreign ions were also investigated. The method was successfully applied for determinations of copper in some natural waters and pharmaceutical samples.     

Inorganic and organometallic cobaloximes with dioxime containing Se side chain: Synthesis, characterization and comparison with related B12 model compounds

New series of cobaloximes, RCo(dSePhgH)₂Py (R = Cl, Me, Et, n-Pr, n-Bu, Bn, 4-ClC₆H₄CH₂) have been synthesized and characterized by NMR and elemental analysis. Molecular oxygen insertion in the benzyl complexes under photochemical conditions has been carried out and a comparison of its reaction rate with other similar cobaloximes gives the order dmestgH > dSePhgH > dpgH > dSPhgH ≥ dmgH > gH. The molecular structures of ClCo(dSePhgH)₂Py, MeCo(dSePhgH)₂Py, BnCo(dSePhgH)₂Py, 4-ClC₆H₄CH₂Co(dSePhgH)₂Py and a dioxy complex Bn(O₂)Co(dSePhgH)₂Py have been determined by X-ray crystallography. The SePh groups in these complexes adopt either up-down, up-down or down-down, down-down conformations in the solid state depending upon the steric bulk and steric interactions with the axial ligand and also their orientation affects the NMR chemical shifts.     

Mizoroki-Heck reaction, catalysis by nitrogen ligand Pd complexes and activation of aryl bromides

Nitrogen ligands are an excellent alternative for the traditional P-ligands in the Pd catalyzed Mizoroki-Heck reaction. Pd complexes of dimethyl glyoxime, 8-hydroxyquinoline, salen, picolinic acid, DAB ligands gave high yields of the E-cinnamates and E-stilbenes. Acetophenone oxime N,N-dimethybenzyl amine and ferrocenyl oxime palladacycle were better catalysts and comparable yields, TON (95,000) and TOF's (2500 h⁻¹) to P-ligand catalysts, were obtained. Aryl iodides, aryl bromides and in a few cases, aryl chlorides could be also be activated by these complexes by the use of Lewis acid and (C₄H₉)₄NI as additive. DAB ligands gave good yields with electron rich aryl bromides and the use of ionic liquid improved the yield. These metal complexes can be readily synthesized and the N-ligands possess the advantage of easy functional group modifications and convenient synthetic methods compared to P-ligands. The degradation reactions associated with P-ligands is not observed in the N-ligands, with comparable high thermal, moisture and air stability and insensitivity.