荧光光度法同时测定稀土氧化物中铈钆铽

在０．６ｍｏｌ．Ｌ＾－１的 到介质中,分别用２５２、２７３、２２０ｎｍ作为Ｃｅ＾３＋、Ｇｄ＾３＋、Ｔｂ＾３＋的激发波和燕生相应最佳发波长为３５０、３１０和５４４ｎｍ。用盐酸体系测定混合样比用硫酸体系测定时,Ｇｄ＾３＋的检出限提高一倍,Ｇｄ＾３＋抗Ｃｅ＾３＋的干扰能力提高１０倍。同时测定三种离子的回收率在９５．３％～１０８．１％之间。     

GdxY1—XP5O14：Ce,Tb的发光和能量传递：Ⅰ.制备,结构和光谱性质

研究了稀土五磷酸盐Ｇｄｘ１－ＸＰ５Ｏ１４：Ｃｅ，Ｔｂ体系的制备，结构和光谱性质。当ｘ＞０．７时，该材料属单斜晶系Ｉ，Ｐ２１／ｃ结构，当≤０．７时，属单斜晶系Ⅱ，Ｃ２／ｃ结构。研究了ＧｄＰ５Ｏ１４：Ｃｅ，Ｔｂ６ ＹＰ５Ｏ１４：Ｃｅ，Ｔｂ的荧光光谱，确定了通过基质Ｇｄ离子中介的Ｃｅ＾３＋→Ｇｄ＾３＋→Ｔｂ＾３＋能量传递的现象。     

Chelex100螯合树脂与某些金属离子的发光行为及其分析应用

作者观察到Ｅｕ＾３＋、Ｔｂ＾３＋、Ｇｄ＾３＋、Ａｌ＾３＋、Ｇａ＾３＋、Ｉｎ＾３＋、Ｚｒ＾４＋和Ｈｆ＾４＋的二元络合物在水溶液中能够与ＥＤＴＡ型的螯合树脂ｃｈｅｌｅｘ１００形成配位体－金属离子－ｃｈｅｌｅｘ１００的三元络合物，络合物的形成不但改变了它们的光谱性质，而且大大增强了其磷光或荧光强度。利用这一性质，本文制作了测定上述金属离子的流通式光学传感器。实验表明该传感器提高了测定的灵敏度与选择性。     

异丙基膦酸单正辛基酯负载树脂分离稀土元素

以吸着有异丙基膦酸单正辛基酯的大孔聚异丁烯酸甲酯的负载树脂分离１５种稀土元素，研究基分配系数，分离因素。结果表明采用梯度淋洗，可使Ｌａ＾３＋，Ｃｅ＾４＋，Ｎｄ＾３＋；Ｎｄ＾３＋，Ｓｍ＾３＋，Ｅｒ＾３＋，Ｇｄ＾３＋；Ｔｂ＾３＋，Ｄｙ＾３＋，Ｅｒ＾３＋，Ｔｍ＾３＋，Ｙｂ＾３＋，Ｌｕ＾３＋以不同程度得以分离，并呈现明显的四分组效应。     

水杨酸酯—Triton X—100—镥（Ⅲ）（钆（Ⅲ））增敏体系荧光法测定铽和镝

１引言作者等曾报道水杨酸苯酯－ＴｒｉｔｏｎＸ－１００－Ｇｄ３＋增敏体系荧光法测定Ｔｂ３＋。为了进一步提高测定的灵敏度并探讨同时测定Ｄｙ３＋的可能性，本文探讨了乙、丁、戊酯等烷基酯对测定的影响。结果表明，丁酯体系的灵敏皮最高，在该体系中Ｄｙ３＋的特征荧光也明显加强，在Ｌｕ３＋共存下Ｔｂ３＋、Ｄｙ３＋的检测限分别达到０．２和８．０μｇ／Ｌ，对Ｔｂ３＋而言，灵敏度较苯酯－Ｇｄ３＋增敏体系提高了１０倍。２实验部分２．１试剂与仪器１ｇ／ＬＴｂ３＋、Ｄｙ３＋标准溶液；３．５×１０－２ｍｏｌ／Ｌ水杨酸酯（乙、…     

吡嗪—2,3—二羧酸体系导数荧光法同时测定铕,铽

研究了以吡嗪－２，３－二羧酸为荧光试剂应用导数荧光技术同时测定Ｅｕ＾３＋，Ｔｂ＾３＋的最佳条件，共存离子的影响和Ｅｕ＾３＋，Ｔｂ＾３＋－ＰＹＤＡ配合物的配合比，稳定常数及光机理，Ｅｕ＾３＋，Ｔｂ＾３＋的检测限分别达４．０和２．０ｎｇ／ｍＬ，利用本方法成功地测定了稀土试样中铕、铽的含量。     

Gd_xY_（1－x）P_5O_（14）：Ce，Tb的发光和能量传递Ⅱ．Ce→

研究了Ｇｄ＿ｘＹ＿（１－ｘ）Ｐ＿５Ｏ＿（１４）：Ｃｅ＿（０．０１），Ｔｂ＿（０．０２）体系中Ｇｄ的子晶格在Ｃｅ→Ｇｄ→Ｔｂ能量传递中的中介作用规律及ＧｄＰ＿５Ｏ＿（１４），ＧｄＰ＿５Ｏ＿（１４）：Ｃｅ，ＧｄＰ＿５Ｏ＿（１４）：Ｔｂ和Ｇｄ＿ｘＹ＿（１－ｘ）Ｐ＿５Ｏ＿（１４）：Ｃｅ，Ｔｂ的荧光光谱、激发光谱。结果表明，当ｘ＞０．７时，结构从单斜Ⅱ（Ｃ２／ｃ）的层状结构变为单斜Ｉ（Ｐ２＿１／ｃ）的带状结构，Ｃｅ￣（３＋）的发射光谱和Ｇｄ￣（３＋）的吸收光谱交迭增加等是Ｃｅ￣（３＋）→Ｇｄ￣（３＋）→Ｔｂ￣（３＋）能量传递几率增加的主要原因。     

铽—镧（镥,钇）—均苯四甲酸共发荧光体系的研究和应用

研究发现Ｌａ＾３＋（Ｌｕ＾３＋，Ｙ＾３＋）对Ｔｂ＾３＋均苯四甲酸（ＢＴＣＡ）体系具有强烈的共发荧光效应，在最佳条件下，共发光离子Ｌａ＾３＋，Ｌｕ＾３＋，Ｙ＾３＋可分别使Ｔｂ－ＢＴＣＡ体系的荧光增强３１２，１３３和１００倍，介绍了Ｔｂ－Ｌａ（Ｌｕ，Ｙ）－ＢＴＣＡ共发荧光体系的荧光特点，形成条件和影响因素，利用Ｌａ＾３＋（Ｌｕ＾３＋，Ｙ＾３＋）的增敏效应，测定了合成稀土样品和包头稀土标准氧化物中的Ｔｂ     

Gd_xY_（1－x）P_5O_（14）：Ce，Tb的发光和能量传递I．制备、

研究了稀土五磷酸盐ＧｄｘＹ１－ｘＰ５Ｏ１４：Ｃｅ，Ｔｂ体系的制备，结构和光谱性质，当ｘ＞０．７时，该材料属单斜晶系结构当ｘ≤０．７时，属单斜晶系结构。研究了ＧｄＰ５Ｏ１４：Ｃｅ，Ｔｈ和ＧｄｘＹ１－ｘＰ５Ｏ１４：Ｃｅ，Ｔｂ的荧光光谱，确定了通过基质Ｇｄ离子中介的Ｃｅ３＋→Ｇｄ３＋→Ｔｂ３＋能量传递的现象。     

氟化镁锶中铕和铽的电荷迁移及其平衡解析

在氩气氛中，合成子ＳｒＭｇＦ４：ｘＥｕ，ｙＴｂ复合氟化物磷光体，该体系中Ｅｕ＾３＋和Ｅｕ＾２＋共存，随共掺入Ｔｂ浓度的增加，Ｅｕ＾３＋的荧光发射强度降低，Ｅｕ＾３＋的发光增强，并且Ｅｕ＾２＋的ＥＳＲ信号增强，认为Ｅｕ＾３＋和Ｔｂ３＋之间存在的电荷迁移，即Ｅｕ＾３＋Ｔｂ＾３＋→Ｅｕ＾２＋＋Ｔｂ＾４＋，通过半量手段研究了这一电荷迁移反应的平衡常数。     

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.