稀土离子与伴清蛋白结合的光谱研究

在ｐＨ＝７．４和２５℃下，用紫外吸收差光谱进行了Ｅｕ＾３＋对脱伯伴清蛋白的滴定，Ｅｕ＾３＋与脱铁伴清蛋白结合后其差光谱在２４５ｎｍ和２９６ｎｍ处出现吸收峰，在２４５ｎｍ处Ｅｕ＾３＋脱铁伴清旧白配合物的摩尔吸光系数是（２．１±０．１）×１０＾４ｃｍ＾－１．Ｌ．ｍｏｌ＾－１，Ｅｕ＾３＋可占据脱铁伴清蛋白的２个金属离子结合部位，条件平衡常数ｌｏＫＮ＝８．２１±０．２０，ｌｇＫｃ＝４．６０±０．１１，脱铁     

铝(Ⅲ)与脱铁伴清蛋白结合的紫外差光谱研究

在 pH7.4、 0.1mol· L~(－1)N-2-羟乙基哌嗪- N′-2-乙磺酸（ Hepes）及室温条件下,使用紫外吸收差光谱进行了铝(Ⅲ)对脱铁伴清蛋白的滴定。结果表明铝(Ⅲ)与脱铁伴清蛋白结合后其紫外差光谱在 238nm和 291nm处出现吸收峰。在 238nm处铝(Ⅲ)-脱铁伴清蛋白配合物的摩尔吸光系数是 (1.52± 0.04)× 10~4cm~(－1)· mol~(－1)· L。铝(Ⅲ)可占据脱铁伴清蛋白的两个金属离子结合部位,条件稳定常数是 lgK_N=11.21± 0.12,lgKC=9.53± 0.24。 N-端单铁伴清蛋白的紫外差光谱滴定表明,铝 ?优先占据脱铁伴清蛋白的 N端结合部位。     

镧系离子与5,7-二氯-8-羟基喹啉-藏红花三元离子缔合物的萃取-光度分析特性

以Ｓｍ３＋为例研究了Ｌｎ３＋５，７二氯８羟基喹啉（ＤＣＯ）藏红花（ＳＦＴ）形成三元离子缔合物的萃取光度特征。用平衡移动法测定了离子缔合物的摩尔比Ｌｎ３＋∶ＤＣＯ∶ＳＦＴ＝１∶４∶１。在ｐＨ６８０～７５０的范围内，萃取物的λｍａｘ＝５２４ｎｍ，εｍａｘ＝４７０×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。Ｓｍ３＋在０２～１５μｇ·ｍｌ－１范围内符合比尔定律。研究表明镧系离子的相对吸光度（ＡＬｎ／ＡＬａ）随原子序数呈现奇偶变化规律。     

镧系四元混合阴离子配合物[Ln(CCl3COO)2(CH3COO)(Phen)(H2O)]2的合成与晶体结构

在水乙醇溶液中合成了３ 种四元混合阴离子配合物， 用元素分析、ＩＲ、ＵＶ 及单晶Ｘ射线衍射进行了表征。［Ｌａ（ＣＣｌ３ＣＯＯ）２（ＣＨ３ＣＯＯ）（Ｐｈｅｎ）（Ｈ２Ｏ）］２·２ＤＭＦ 晶体属三斜晶系， Ｐ１ 空间群， 晶胞参数：ａ＝ １－２５１０（４） ｎｍ ， ｂ＝ １－３４６０（５） ｎｍ ， ｃ ＝ １－０３４３（３） ｎｍ ， α＝ １０２－４７（３）°， β＝ １０２－３４（２）°， γ＝ １１３－８２（２）°， μ（ＭｏＫα） ＝ ２０．４７ ｃｍ －１ ， Ｚ＝ １， Ｄｃ＝ １－８００ ｇ·ｃｍ － ３ ， Ｆ（０００） ＝ ７８０－００。稀土配合物中醋酸根以桥联方式配位， 三氯醋酸根则有２ 种配位方式， 在二者共同参与配位的体系中呈现出丰富的配位模式。     

3-硝基-1,2,4-三唑-5-酮镱配合物的制备及其晶体结构

３硝基１，２，４三唑５酮（ＮＴＯ）的锂盐水溶液与Ｙｂ２Ｏ３的稀硝酸溶液反应，制备了标题配合物，其化学式为Ｙｂ（ＮＴＯ）３·１０Ｈ２Ｏ。用Ｘ射线衍射法测定配合物的晶体结构，其分子式为［Ｙｂ（ＮＴＯ）３（Ｈ２Ｏ）４］·６Ｈ２Ｏ。属单斜晶系，空间群为Ｃ２／ｃ。晶胞参数如下：ａ＝３６９３１（５）ｎｍ，ｂ＝０６６８３（１０）ｎｍ，ｃ＝２５６５６（３）ｎｍ，β＝１３０９７４（５）°，Ｖ＝４７８１１（１１）ｎｍ３，Ｚ＝８，Ｄｃ＝２０１３ｇ·ｃｍ－３，μ＝４０１７ｍｍ－１，Ｆ（０００）＝２８５０。镱离子的配位数为７，其配位多面体为五角双锥。     

Eu2+在多相体系中的发光

研究了基质结构与离子半径的形成关系和Ｅｕ２＋在同时形成的多相体系中的发光现象．在ＭＭｇＡｌ１０Ｏ１７体系中,当Ｍ离子半径小于０．１０ｎｍ时,体系形成多相共存．首次观察到在磁铅矿、尖晶石和α－Ａｌ２Ｏ３三相同时共存体系中,Ｅｕ２＋优先占据离子半径和电荷与之匹配的磁铅矿中的Ｃａ２＋离子格位,不进入尖晶石和α－Ａｌ２Ｏ３晶相中的Ｍｇ２＋、Ａｌ３＋离子格位,仅产生Ｅｕ２＋的ｄ→ｆ跃迁宽带发射,且观察不到Ｅｕ３＋的特征光谱;在尖晶石和α－Ａｌ２Ｏ３两相同时共存体系中,Ｅｕ２＋可进入尖晶石和α－Ａｌ２Ｏ３晶相中的Ｍｇ２＋、Ａｌ３＋离子格位,分别产生Ｅｕ２＋的ｄ→ｆ和ｆ→ｆ跃迁发射,同时还观察到相当强的Ｅｕ３＋的特征光谱;在α－Ａｌ２Ｏ３单一相中,Ｅｕ２＋产生ｆ→ｆ跃迁发射,并观察到明显的Ｅｕ３＋的特征光谱,在α－Ａｌ２Ｏ３与γ－Ａｌ２Ｏ３同时存在的混合相中,Ｅｕ２＋的ｆ→ｆ跃迁发射消失,产生新的ｄ→ｆ跃迁宽带发射     

稀土-NTO配合物晶体结构的多样性研究

用３硝基１，２，４三唑５酮（ＮＴＯ）的锂盐与稀土硝酸盐反应，制备ＮＴＯ镨、铕、镝、镱、钇五种配合物单晶。Ｘ射线衍射方法测定配合物的晶体结构。研究表明ＮＴＯ作为配体与稀土形成配合物时，表现出ＮＴＯ环上的羰基氧原子与稀土金属形成配位键的共性；配合物的空间结构随中心稀土离子半径的变化而变化，随着稀土离子半径的变小，较大体积配体ＮＴＯ－的配位数目逐渐变小。     

稀土透明树脂的制务圾吸收和荧光性能

采用稀土氧化物如Ｓｍ２Ｏ３，Ｅｕ２Ｏ３，Ｎｄ２Ｏ３与甲基丙烯酸（ＭＡ）制备了多种可事的甲基丙烯酸盐，然后和ＭＡ、苯乙烯共聚得到了多种厚度在１．５ｍｍ的透明树脂。在稀土元素含量为０－３％ｗｔ，可见及近红外（１５００ｎｍ以下）的透光率在８０５以上；含Ｓｍ＾３＋或含Ｎｄ＾３＋的树脂的透过光谱上出现了Ｓｍ或Ｎｄ的吸收峰。含不同稀土的树脂在３８３ｎｍ或４２７附近有聚集苯环的很强的荧光发射，同时有对应于稀土元     

铕-对氨基苯甲酸-邻菲咯啉配合物[Eu(p-ABA)_3Phen·H_2O](C_2H_5OH)的晶体结构

［Ｅｕ（ｐＡＢＡ）３Ｐｈｅｎ·Ｈ２Ｏ］（Ｃ２Ｈ５ＯＨ）（ｐＡＢＡ＝对氨基苯甲酸根，Ｐｈｅｎ＝邻菲咯啉）配合物晶体属三斜晶系，Ｐ１空间群，ａ＝１２２６８（３）ｎｍ，ｂ＝１４００５（３）ｎｍ，ｃ＝１０４４０（３）ｎｍ；α＝１０２６９（２）°，β＝１０８９３（２）°，γ＝９２８５（２）°；Ｚ＝２，Ｔ＝２７３Ｋ。最终的Ｒ因子为００３９。配合物中心Ｅｕ３＋离子与周围ｐＡＢＡ的６个氧原子和Ｐｈｅｎ的一对氮原子以及一个水分子的氧原子配位，配位多面体属畸变的单帽四方反棱柱体，水分子的氧原子占据帽位。     

皂化酸性磷酸酯萃取稀土离子过程中有机相的FTIR光谱表征

研究了不同浓碱皂化的Ｄ２ＥＨＰＡ－正庚烷体系萃取－系列稀土离子（Ｌａ＾３＋－Ｌｕ＾３＋）放射性的Ｐｍ除外）过程中有机相的ＦＴＩＲ光谱变化规律，结果说明，Ｄ２ＥＨＰＡ萃取稀土离子后，Ｐ－Ｏ基团５的红外吸收频率降低，吸收强度升高，说明Ｐ－Ｏ基团与稀土离子发生配位；红外光谱研究研究结果表明：不同稀土离子与Ｐ－Ｏ配位能力有差别，从Ｌａ＾３＋－Ｓｍ＾３＋ｓｇｎ ｗｕｇ ｃｅｌｔｗｙｅ ｕｑｗ ｆｕｌｊｅ ｓ     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

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.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

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.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.