铱(Ⅲ)卟啉β-羟乙与基醛的碳氢键活化(英文)

铱(Ⅲ)卟啉β-羟乙基,IrⅢ(ttp)CH2CH2OH(ttp=5,10,15,20-二价阴离子tetratolylporphyrinato),发现选择性裂解芳醛的醛的碳-氢键和给铱酰基配合物。酰基铱配合物对羰基化和脱羰反应以及潜在的功能化研究的很好的候选材料。这碳-氢键的建议活化机理:通过初始的β-羟基消除IrⅢ(ttp)CH2CH2OH生成IrⅢ(ttp)OH,然后进行与醛的CH键的σ-键复分解发生。     

铱配合物的电致化学发光性能研究

结构相关的铱配合物[Ir(ppy)2L1](PF6)和[Ir(ppy)2L2](PF6)(ppy=2-苯基吡啶,LI=4-(2,2'-联吡啶-3-乙炔基)-N-(吡啶-2-亚甲基)-N-(噻吩-3-亚甲基)苯胺,L2=4-(2,2'-联吡-3-乙炔基)-N-二(吡啶-2-亚甲基)-苯胺)都具有优良的电致发光(ECL)性...     

羧基化碳纳米管嵌入石墨修饰电极对多巴胺和抗坏血酸的电催化

采用涂层和嵌入修饰法 ,将羧基化多层碳纳米管制成两种修饰电极。以多巴胺 (DA)和抗坏血酸(AA)为模型化合物 ,研究了两种修饰电极对DA和AA共存时的电催化作用。结果表明 :嵌入的方式比涂层的方式显示了更多的优点。嵌入修饰电极不仅使峰电流增加 ,并且使两者共存时的氧化峰位分离达 16 0mV ,同时 ,该电极对DA的响应灵敏于AA ,这有利于在大量的AA存在下实现对DA的测定。在 1× 10 - 3 mol/L的AA的存在下 ,还原电流的一阶导数与DA浓度在 5× 10 - 7～ 1× 10 - 4 mol/L范围内呈良好的线性关系 ;检测下限达 1× 10 - 7mol L。     

乙基罗凡明B指示反应动力学光度法测定痕量铱

提出了动力学光度法测定铱。在磷酸 -氯化钠介质中 ,Ir( )催化高碘酸钾氧化乙基罗丹明 B( ERB)形成褪色化合物 ,适宜条件为 c Na Cl=0 .0 2 mol/ L ,c H3PO4 =0 .1 0 mol/ L ,c KIO4 =2 .0× 1 0 - 3mol/ L ,c ERB=1 .7× 1 0 - 5mol/ L ,I=0 .0 2 ,90℃。铱浓度在 0 .4～ 32μg/L范围校正曲线成直线 ,检出限为 4.0× 1 0 - 10 g/ m L,对 2 0 μg/ L铱测定 1 1次的 RSD为1 .55% ,体系至少稳定 8h。考察了 30多种共存离子的影响。本法满意地用于某些冶金产品和矿石中铱的测定。铱催化反应对 Ir( )、ERB、KIO4 和 H3PO4 均为一级反应 ,表观活化能为 75.82 k J/ mol,探讨了反应机理     

In(Ⅲ) -NCP体系配位吸附波研究及应用

在0.15 mol/L HAc-NaAc(pH 3.2)介质中,In(Ⅲ)-NCP(2,9-二甲基邻菲咯啉)配合物在2.5次微分极谱图上产生良好的吸附还原波.其峰电位为-0.40 V,峰电流与In(Ⅲ)浓度在4.0×10-8～2.0×10-6 mol/L范围内呈良好的线性关系,检出限为8.0×10-9 mol/L.应用该法测定了氢氧化铝和陶瓷颜料中的微量铟,结果满意.研究了配合物的组成、极谱波的性质及其机理.     

二甲基黄催化动力学光度法测定痕量铱

基于在H3PO4介质中,Ir(Ⅳ)对KIO4氧化二甲基黄的反应具有催化作用,建立了测定痕量铱的新催化光度法.测定铱的线性范围为(3.2～8.8)×10-2 μg/mL,检出限为7.54×10-7 g/L.对0.04 μg/mL Ir(Ⅳ)测定的相对标准偏差为1.5%(n=11).该催化反应对Ir(Ⅳ)和二甲基黄均为一级反应,其表观活化能为103.8 kJ/mol.试验了40多种共存离子的影响,大多数的常见离子不干扰测定.用该方法测定了岩矿和冶金产品中铱的含量,相对标准偏差为0.93%～2.5%,加标回收率为98.2%～102%.     

铁(Ⅲ)-2-(5是′-溴-2′-吡啶偶氮)-5-二乙氨基苯酚配合物1.5、2.5阶微分吸附伏安法研究

本文讨论了铁(Ⅲ)-2-(5＇-溴-2＇-吡啶偶氮)-5-二乙氨基苯酚配合物1.5、2.5阶微分吸附伏安法电流1.5、2.5阶微分峰峰值的表达式。实验结果表明,1.5、2.5阶吸附伏安法的线性范围为1×10~(-10)～1×10~(-7)mol/L,对2.5阶微分吸附伏安法,富集2min的检测下限为5×10~(-11)mol/L。用此法测定了人发中的痕量铁。     

碳纳米管修饰电极对多巴胺和肾上腺素的电分离及同时测定

研究了多巴胺 (DA)和肾上腺素 (EP)在多壁碳纳米管 (MWNT)修饰电极上的电化学性质 ,发现该修饰电极对神经递质DA和EP有显著的增敏和电分离作用。还原峰电位差达ΔEp=390mV ,可同时测定DA和EP。DA和EP的还原峰电流与其浓度分别在 2 .0× 10 -6～ 1.0× 10 -3 mol/L和 1.0× 10 -6～ 1.0× 10 -3 mol/L浓度范围内呈良好的线性关系 ;方法的检出限分别为 1× 10 -6mol/L和 5× 10 -7mol/L。由于抗坏血酸 (AA)在MWNT修饰电极上的氧化是不可逆的 ,因此利用还原峰进行测定 ,消除了AA对DA和EP的干扰     

基于水溶性共轭聚合物荧光增强测定精氨酸

在水溶液中,精氨酸(Arg)能使水溶性共轭聚合物P1的荧光高灵敏、特异性地增强,从而建立了一种免标记的荧光增强型Arg检测新方法.该方法Arg检测的线性范围为6.0×10-8～3.06×10-6 mol/L和3.06×10-6～7.11×10-5 mol/L;检出限为2.0×10-8 mol/L.方法简单、快捷、选择性好、灵敏度高,可用于盐酸精氨酸注射液样品的检测.     

AuR2+-鲁米诺-K2S2O8化学发光体系与应用

研究了 8 羟基喹啉 (HR)与Au(Ⅲ )形成的配合物AuR+ 2 ,对K2 S2 O8氧化鲁米诺的增强作用 ,基于此建立了金的化学发光分析新方法 .以 8 羟基喹啉为配位体时 ,Au(Ⅲ )的检出限为 8× 10 -11μg/L ,工作曲线响应浓度范围在 1× 10 -9～ 1× 10 -7μg/L ,测定 1× 10 -7μg/LAu(Ⅲ )离子的RSD为 2 .0 % .配合物化学发光法检测硅酸盐单矿物晶格中痕量金可获得较好的分析结果     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.