铬的化学形态分析进展

有关痕量元素形态的研究已成为当今科学领域的活跃领域之一,是分析工作者必须面对的新课题.同一元素不同的化学形态导致不同的环境毒害、生物效应和对人体健康有不同的影响.铬是VIB族元素,在地壳中的平均含量为 0.010%～0.011%,分布广泛.工业上主要用于制造各种优质合金,也广泛用于皮革、印染、电镀等工业,受腐蚀后以各种排放液进入环境.铬有多种价态,最常见的是三价和六价.研究表明,铬表现为必需元素还是有害元素,其价态起决定性作用.三价铬是人体必需的微量元素,是正常糖脂代谢所不可缺少的,缺铬会引起动脉硬化等多种疾病.六价铬由于其氧化性和对皮肤的高渗透性,毒害很大,被确认有致癌作用.铬形态分布也影响铬在环境中的迁移转化规律.因此铬的形态分析在环境科学、生命科学、生理医学等方面都有重要的意义.     

3-(四氯化锡)-丙酸甲酯阴离子的合成及晶体结构

在用酯基锡MeO2CCH2CH2SnCl3合成配合物MeO2CCH2CH2SnCl3·(2-OHC6H4CH=NC6H5)时,其配合物的甲苯溶液放置培养单晶时(放置十天以上)会发生分解生成配合物MeO2CCH2CH2SnCl4—·H+。研究了标题化合物的合成反应,用元素分析、IR、NMR对配合物进行了表征,并测定了晶体结构。为正交晶系,空间群为P2cn, a=7.852(2), b=12.236(1), c=16.952(4) ? V=1628.7?, Z=4, Dc=1.79g/cm3, F(000)= 860,m=22.2cm—1(Mo),R=0.0449, Rw=0.0382。标题化合物的空间构型为畸变的八面体构型,中心锡原子的配位数为6。     

环境监测现状

目前，全国已形成了国家、省、市、县四级环境监测网络，共有专业、行业监测站4800多个，其中环保系统监测站2200多个，行业监测站2600多个，国控的空气质量监测网站103个，酸雨监测网站113个，水质监测网站135个。同时，还建有噪声监测网、辐射监测网和区域监测网等。到2005年，国控环境监测网络调整为：环境空气监测网站226个，测点数793个；酸雨监测网站239个，测点数472个；水质监测网站197个；监测断面1074个；生态监测网站15个。目前，我国已制定各类国家环境标准410项，覆盖了大气、水质、土壤、噪声、辐射、农药等领域。开展了环境质量监测，     

汞膜电极示波极谱法测定冶金废水中铅和锰

汞膜电极是一种灵敏度较高的固体电极,已广泛地被应用于痕量物质的测定,已见铝合金中铋、铜、铅的同时测定及铜合金中低含量铅的测定,但未见汞膜电极示波极谱法同时测定铅和锰。本文利用自制的汞膜电极在乙酸铵-铜铁试剂体系中实现了Pb~(2+)、Mn~(2+)的测定,常见阴、阳离子不干扰。此方法测定pb~(2+)和Mn~(2+)的线性范围宽,灵敏度高,适于现场操作。Pb~(2+)和Mn~(2+)的检测下限分别达0.005μg·ml~(-1),0.1μg·ml~(-1),分析快速,易于推广,汞膜电极性能稳定。本法应用于冶金废水中铅、锰的测定,获得了满意结果。     

Synthesis and Structure Characterization of [HgCl(η~5-C_5H_3C(CH_3)=N-3- C_5H_4N)Fe(η~5-C_5H_5)]·(1/2)CH_2Cl_2

1INTRODUCTIONThechemistryofcyclomercuratedferrocenyl-imineshasbeenofgeneralinterestfordecades,owingtotheirvariousapplicationsinorganicsynthesis,materialscience,catalysisandphoto-chemistry[1].Wehavealsostudiedalotofthesekindsofcompounds[2].Moreover,itisrep…     

Fabrication, Characterization and Electrocatalysis of an Ordered Carbon Nanotube Electrode

A method for fabrication of ordered carbon nanotube (CNT) film,which was template-synthesized within the highly ordered pores of a commercially available alumina template membrane,modified glassy carbon(CNT/GC) electrode was established.The CNT/GC electrode showed excellent electrocatalytic activity toward dopamine electrochemical reaction without introducing any electrochemically active group into CNT film or activating any electrochemically active group into CNT film or activating the electrode electrochemically.DA undergoes ideal reversible electrochemical reaction on CNT/GC electrode at low scan rate(≤20mV/s) with an excellent reproducibility and stability.The CNT/GC electrode might be used in biosensors because the highly ordered CNT may present a steric effect on more efficient redox reactions of biomolecules.     

Synthesis of Eu(III) and Tb(III) Complexes with Two New Amide Type Podands and Their Luminescence Properties

ＩｎｔｒｏｄｕｃｔｉｏｎＬａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｈａｖｅａｔｔｒａｃｔｅｄｍｕｃｈａｔｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｔｈｅｉｒｉｍｐｏｒｔａｎｔａｐｐｌｉｃａｔｉｏｎｓ .1ＩｎｐａｒｔｉｃｕｌａｒＥｕ(ＩＩＩ)ａｎｄＴｂ(ＩＩＩ)ｃａｎｂｅｃｈａｒａｃｔｅｒｉｚｅｄｂｙｌｏｎｇ ｌｉｖｅｄ(ｍｓｔｉｍｅｓｃａｌｅ)ａｎｄｓｔｒｏｎｇｌｕｍｉｎｅｓｃｅｎｔｅｌｅｃｔｒｏｎｉｃａｌｌｙｅｘ ｃｉｔｅｄｓｔａｔｅｓ ,ｗｈｉｃｈｍａｋｅｓｔｈｅｍｉｍｐｏｒｔａｎｔｉｎａｎａｌｙｔｉｃａｌｃｈｅｍ…     

[Ce(NO3)5H2O]·(C3H5N2)2的合成、晶体结构及热分析

Colorless crystal, [Ce(NO₃)₅H₂O]·(C₃N₂H₅)₂, has been obtained from the reaction of Ce(NO₃)₃ with imdazole in the aqueous solution and its crystal structure has been determined by single crystal X-ray diffraction techniques.The crystal belongs to triclinic, space group P1. The cell parameters are: a = 0.7489(1) um, b = 0.7914(2) nm, c = 1.8139(3) nm, a = 89.39(2)°, β = 89.37(l) °,γ = 63.18(2)°, Dc = 2.1g·cm^-3, Z = 2, R = 0.0319.In the compound, all of five nitrates are bidentate and one molecule of water is monodentate, the coordination number of Ce (Ⅲ) is 11.The processes of thermal decomposition of the compound was proposed by its TGcurve.     

高分子光敏剂研究进展

本文综述了近年来国际上关于高分子光敏剂的研究工作进展．     

[COH(NH2)2]2[Cu(pic)2(ClO4)2]的合成与晶体结构

The title compound was synthesized by reaction of Cu(ClO₄)₂， picolinic acid and carbamide in C₂H₅OH/CH₃CN solution， and characterized by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system， space group Pbca with a=14.0481(8)， b=9.0130(5)， c=18.626(1)?， V=2358.3(2)?³， Z=4， D_x=1.771g·cm^-3， μ=1.235mm^-1 and F(000)=1276. The final R factor is 0.0440 for 1434 observed reflections. The X-ray analysis revealed that the copper(Ⅱ) atom is coordinated by two picolinic ligands in the equatorial plane， while the two oxygen atoms of perchlorate occupy the axial positions of octahedron with lengthened Cu-O distances， resulting in a 4+2 elongated octahedral environment. In the compound， there also exist two protonated carbamide cations for charge balance. CCDC： 195354.