Synthesis, crystal structure and properties of the Cu complex of a tetradentate imidazole-functionalized diazamesocyclic ligand, 1,4-bis(N-1-methylimidazol-2-yl-methyl)-1,4-diazacycloheptane

A new potential tetradentate ligand, 1,4-bis(N-1-methylimidazol-2-ylmethyl)-1,4-diazacycloheptane (l), together with its Cu^II complex [CulCl]ClO₄ (1), has been reported. The crystal structure of 1, determined by single-crystal X-ray analysis, shows that it is in chiral P2₁2₁2₁ space group. The Cu^II centre is penta-coordinated in square pyramidal geometry and the diazacycloheptane (DACH) ring adopts normal boat configuration. The most striking feature of this complex is the formation of a 3D network bridged through the C-H?Cl hydrogen bonds with the perchlorate anions in the cavities, and stabilized via π-π stacking interactions along the a-direction. The solution behaviour of 1 has been further investigated by UV/Vis and ESR techniques.     

DEHYDROGENATION AND AROMATIZATION OF METHANE IN THE ABSENCE OF OXYGEN OVER DOPED Mo/HZSM-5 CATALYSTS

研究了在Ｍｏ／ＨＺＳＭ－５催化剂上添加助剂以及不同的反应预处理温度对甲烷无氧脱氢芳构化反应的影响。实验结果表明，由于第二组分的添加，Ｍｏ／ＨＺＳＭ－５催化剂的活性和选择性都得到了较大程度的改善。预处理温度是影响催化剂反应性能的关键因素。Ｍｏ－Ｒｕ／ＨＺＳＭ－５催化剂经过８７３Ｋ空气预处理后，甲烷在９７３Ｋ的转化率约为１０％，催化剂的稳定性也得到较大程度的提高。ＴＰＳＲ实验结果表明，Ｒｕ的加入降低了芳烃生成的温度。ＴＰＯ和ＤＴＡ实验结果表明，在Ｍｏ－Ｒｕ／ＨＺＳＭ－５催化剂上可生成较多的碳物种，结合反应结果，可以认为反应过程中生成的碳物种对甲烷的无氧脱氢芳构化反应是起积极作用的     

Speciation analysis of tellurium by solid-phase extraction in the presence of ammonium pyrrolidine dithiocarbamate and inductively coupled plasma mass spectrometry

Under acidic conditions tellurium(IV) formed a complex with ammonium pyrrolidine dithiocarbamate (APDC). The tellurium(IV) complex was completely retained on a non-polar Isolute silica-based octadecyl (C(18)) sorbent-containing solid-phase extraction (SPE) cartridge, while the uncomplexed Te(VI) passed through the cartridge and remained as a free species in the solution. Only partial Te(IV) was retained on the SPE cartridge for samples without addition of APDC. On the basis of different retention behaviours of the complexed Te(IV) and uncomplexed Te(VI), a simple and highly sensitive method is proposed for the determination of total tellurium and Te(VI) by SPE separation and inductively coupled plasma mass spectrometry (ICP-MS) detection. The Te(IV) concentration was calculated as the difference between total tellurium and Te(VI) concentrations. The detection limit (3 sigma) is 3 ng L(-1) tellurium. Factors affecting the separation and detection of tellurium species were investigated. Coexisting ions did not show significant interferences with the Te(IV)-APDC complex retention and the subsequent ICP-MS detection of Te. The method has been successfully applied to the tellurium speciation analysis in waters with spiked recoveries for Te(IV) and Te(VI) of 86.0-108% and 87.1-97.4%, respectively.     

含环氧端基酚酞聚芳醚酮E-PEK的合成及表征

由酚酞和4,4′-二氯二苯酮经亲核缩聚制得了一系列不同分子量的含—OK端基的聚醚酮低聚物,将其与环氧氯丙烷反应得到了分子量为1000～8000的含环氧端基聚芳醚酮(E-PEK)。用IR和~1H NMR表征了E-PEK的分子链结构,测定了T_g、溶解性和熔融粘度。研究了E-PEK/DDE体系的固化,固化后树脂的T_(g∞)=183～215℃,与低聚物的初始分子量有关。     

红外光谱研究甲烷和氧与SrO-La2O3/CaO表面的相互作用

在甲烷氧化偶联（ＯＣＭ）反应条件下，用原位红外光谱研究ＳｒＯ－Ｌａ２Ｏ３／ＣａＯ催化剂，结果表明，晶格氧使甲深度氧化，Ｌａ２Ｏ３和ＣａＯ具有活泼的晶格氧，ＳｒＯ的晶格氧比较稳定，气相氧通过催化剂表面消耗掉的晶格氧，加速甲烷了深度氧化，另一方面，催化剂表面的碳酸根物种在氧气氛下分解，在Ｌａ２Ｏ３和ＬＣ催化剂中，催化剂表面Ｌａ２Ｏ２（ＣＯ３）的分解形成配位不饱和的晶格氧Ｏ＾２－，并为气相氧吸附提供氧空     

Application of Nafion／Cobalt Hexacyanoferrate Chemically Modified Electrodes for the Determination of Electroinactive Cations by Ion Chromatography

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｉｏｎｃｈｒｏｍａｔｏｇｒａｐｈｙ (ＩＣ)ｈａｓｂｅｅｎｒｅｃｏｇｎｉｚｅｄａｓａｕｓｅｆｕｌｍｅｔｈｏｄｆｏｒｔｈｅｓｅｐａｒａｔｉｏｎｏｆｉｎｏｒｇａｎｉｃａｎｉｏｎｓａｎｄｃａｔｉｏｎｓｓｉｎｃｅｉｔｓｉｎｔｒｏｄｕｃｔｉｏｎｂｙＳｍａｌｌｅｔａｌ .ｉｎ 1975 .1ＡｓｉｇｎｉｆｉｃａｎｔｔｒｅｎｄｉｎｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆＩＣｍｅｔｈｏｄｉｓｓｅａｒｃｈｆｏｒｓｅｎｓｉｔｉｖｅａｎｄｕｎｉｖｅｒｓａｌｄｅｔｅｃｔｉｏｎｍｅｔｈｏｄｓ .Ｔｈｅｍａｉｎｄｅｔ…     

5-Br-PADCAP分光光度法测定血清锌

为建立快速、简便、灵敏的分光光度法测定血清锌 ,在表面活性剂TritonX -1 0 0存在下 ,用 2 -(5 -溴 -2 -吡啶偶氮 ) -5 -[N ,N -二羧基甲基 ]苯酚 (5 -Br-PADCAP)作显色剂 ,不去蛋白分光光度法测定血清锌。结果表明 ,锌络合物最大吸收波长为 5 5 7nm ,线性范围 0～ 5 0 0μmol L ,摩尔吸光系数为 1 1 2× 1 0 5L·mol-1·cm-1。回收率为 99 9% ,批内变异系数 (CV)为2 1 % ,批间变异系数为 2 9% ,与原子吸收分光光度法 (x)比较具有良好的相关性 ,y =1 0 1 0x-0 1 5 4,r=0 991 8,P >0 0 5。可见本法测定血清锌不必去蛋白、用血量少、方法简便、灵敏可靠 ,适合临床应用     

Experimental and computational studies of intracomplex reactions in Mg+(primary, secondary alkylamine) complexes induced by photoexcitation of Mg+

We report herein a comprehensive study of photoinduced reactions in complexes of Mg+ with primary (n-propyl- and isopropylamine) and secondary amines (dipropyl- and diisopropylamine) in the spectral range of 230-440 nm. Similar to the methyl- and ethylamine complexes studied previously, N-H bond activation of these complexes is very unfavorable. Instead, the C(alpha)-C, C-N, and C(alpha)-H bond-cleavage photoproducts are observed after photoexcitation of the Mg+ complexes (3(2)P<--3(2)S). For Mg+(primary amine) complexes, for example, Mg+-NH2CH2CH2CH3, and Mg+-NH2CH(CH3)2, the photoproducts resulting from C(alpha)--C rupture prevail after P(z) and charge-transfer excitations, whereas the Mg+ photofragment is predominant upon P(x,y) excitation. However, with further N-alkyl substitution, as in Mg+(secondary amine) complexes, for example, Mg+-NH(CH2CH2CH3)2 and Mg+-NH[CH(CH3)2]2, a novel intracomplex C-C coupling photoreaction dominates on P(x,y) excitation of Mg+, which is believed to arise from Mg+* insertion into the C-N bond. With P(z) and charge-transfer excitation, the Mg-R elimination photoproducts, arising from C(alpha)-C bond cleavage, predominate. The energetics and possible mechanisms of the intracomplex photoreactions are analyzed in detail with the help of extensive quantum mechanics calculations.     

钾镁氯化物(硫酸盐)与脲、水体系的溶度研究

报导了KCl-MgCl2-CO(NH2)2-H2O和K2SO4-MgSO4-CO（NH2）2-H2O两个四元体系在25℃时的溶度及其饱和溶液的折光率、密度，相应的溶度图和组成-折光率、组成-密度图．前一体系中形成3个三元化合物：MgCl2·4CO（NH2）2·2H2O、MgCl2·CO（NH2）2·4H2O和KCl·MgCl2·6H2O溶度盐份图由9支共饱线、4个四元无变点组成．四元体系的水量图、性质-组成图有类似的变化．后一体系中有2个异成份溶解化合物MgSO4·CO（NH2）2·2H2O和K2SO4·MgSO4·6H2O形成，溶度等温图由7支双饱溶度线、3个四元无变点组成．对两个体系相图的相似性和差异点进行了讨论．     

C5,5—取代基对海因质子亲合能的影响

文章对５种碳五位（Ｃ５）的不同取代基海因的质子北合能（ＰＡ）,在亚稳状态下采用“动能法”进行了研究。以５,５－甲基海因作为参照,确定了５种样品亲质子能的顺序。