几种矿物酸为流动相对HEH(EHP)萃取柱色谱分离稀土的影响

本文研究了以 HEH(EHP)为固定相,盐酸、硝酸、高氯酸和硫酸为流动相,萃取柱色谱法分离稀土元素.其平均分配系数为:■_(H_2SO_4)(3.87)>■_(HCl)(3.47)>■_(HClO_4)(3.44)>■_(HNO_3)(2.68).其分配系数的顺序为:HClO_4>H_2SO_4>HNO_3>HCl.因此,盐酸是较好的流动相.在盐酸洗脱液中加入1M 氯化铵,使 La、Ce、Pr、Nd 分离的洗脱体积减少近3/4.     

叔铵盐—烷烃—醇—水四元体系的热力学函数与结构研究

叔铵类(R_3N)萃取剂萃取金属离子需在酸性介质中进行,与无机酸先形成铵盐(属阴离子表面活性剂类),然后与金属配阴离子进行阴离子交换反应。而将R_3N制成无机酸盐,作为表面活性剂以微乳液为模型对其进行热力学函数与结构研究尚未见报道。 本文制备了TOA·HCl、N235·HCl、N235·HNO_3与N235·HClO_44种叔铵无机酸盐,测定了叔铵盐的界面化学性质。以w/o型微乳液的球形颗粒结构为模型,用稀释法测定了叔铵盐(TOA·HCl,N235·HCl,N235·HNO_3,N235·HClO_4)-烷烃-醇-水四元均相透明体系的结构参数;并用不同醇时,醇由油相(o)转移至界面层(i)的标准自由能变(?)结果表明其结构“颗粒”半径小于0.5nm,表面活性剂叔铵盐的平均聚集数小于0.05,应属醇的反向胶团。 1 实验 1.1 试剂 三正辛胺(TOA,德国);N235(R_3N,R=C_5—C_(10),大连油脂化学厂)。叔铵盐TOA·HCl分别用干法(D)与湿法(W)制备。向TOA中通入干燥HCl气体至饱和,再加入分析量的TOA中和过量的HCl,制得TOA·HCl(D).TOA与过量10mol/L盐酸振荡平衡,再加入分析量的TOA中和过量酸制得TOA·HCl(W),样品均为淡黄色蜡状固体,N235·HCl、N235·HNO_3、N235·HClO_4均用湿法制备。其它试剂均为A.R.级,未进一步处理,水为二次蒸馏水。     

仲碳伯胺萃取铈(Ⅳ)机理的~1H,~(15)N核磁共振谱研究

仲碳伯胺N_(1923)萃取铈(Ⅳ)的~1H,~(15)N-NMR研究表明,在萃取铈(Ⅳ)时也同时萃取H_2O和H_2SO_4进入有机相,当铈(Ⅳ)浓度较高时,铈(Ⅳ)与N_(1923)生成配合物。     

GRAFT COPOLYMERIZATION OF VINYL MONOMERS ONTO STARCH INITIATED BY TRANSITION METAL-THIOUREA REDOX SYSTEMS

In this paper, the capabilities of grafting acrylonitrile (AN) onto starch initiatedby Fe(III)-TU, V(V)-TU, Cr(VI)-TU, Mn(VII)-TU redox systems were compared in thepresence of sulfuric acid of different concentrations. It was shown that the grafting capabili-ty of Mn(VII)-TU is the highest in these initiating systems. Using Mn (VII-TU as initia-tor, the effects of various acids (HClO_4, H_2SO_4, HNO_3, HCl) on the graft copolymerizationof acrylonitrile onto starch were discussed, and the capabilities of graft copolymerizationof methyl methacrylate (MMA), acrylamide (AM), acrylic acid (AA) onto starch wereinvestigated. The experimental results show that the order of the influences of differentacids is HClO_4>H_2SO_4>HNO_3>HCl, and the order of grafting capabilities of differentmonomers grafted onto starch is MMA>AN>AM>AA. The structure and morphology ofgraft copolymers were studied with infrared spectroscopy and scanning electron microscopy.The size, shape and roughness of surface of the grafted starch granules are changed aftergrafting.     

方波悬汞吸附伏安法测定八氧化三铀中的钛

U_3O_3用HNO_3溶解,用TBP萃淋树脂分离铀,水溶液用HClO_4蒸干,残渣溶于10ml、pH=6.1的0.1mol/L EDTA、lmol/L的NaAc溶液中,加入1％铜铁试剂0.5ml,于-0.6V～-1.1V的电位范围内用方波伏安法测定钛。标准偏差约为5％,最低检出限为0.5ng/ml。     

水合苯并—15—冠—5四溴合铟(Ⅲ)酸钠(NaInBr_4)_2(C_(14)H_(20)O_5)_3·2H_2O的晶体结构

本文报道了在乙醇—氯仿混合溶剂中首次获得组份为(NaInBr_4)_2(C_(14)H_(20)O_5)_3·2H_2O的晶体配合物.用元素分析确定了其组份.通过红外光谱的研究证实配合物晶体中的阳离子与醚氧原子及水分子发生了配合作用。 用X-射线衍射法测定了配合物的晶体结构,晶体属单斜晶系,M=1755.3,a=14.393(8)A,b=28.494(9)A,c=15.191(8)A,β=96.63(5)°,V=6189A~3’,D_c=1.88g·cm~(-3),Z=4,空间群为C_(2h)~5——P2_1/n。晶体结构研究表明不对称单位中包含两个配阳离子Na~(+)(B15C5)(B15C5)代表C_(14)H_(20)O_5分子)。两个配阴离子InBr_4~-、两个H_2O分子和一个未被金属离子配合的B15C5分子。配合物的晶体结构测定结果对于阐明与该晶体相对应的萃取体系In(Ⅲ)/NaBr/B15C5—1,2C_2H_4Cl_2的萃取机理提供了理论依据。     

伯胺N1923和三苯基氧化膦萃取金(Ⅲ)的动力学Ⅱ:二元萃取剂体系萃取AuCl4-

用恒界面池法研究了伯胺N1923和三苯基氧化膦(TPPO)二元萃取剂体系从盐酸介质中萃取AuCl4-的动力学,提出了界面化学反应控制机理.认为在界面区域内同时进行着N1923、TPPO以及二者的缔合物萃取AuCl4-的三个平行反应.三者的共同作用使Au(Ⅲ)向有机相的传质较N1923或TPPO的一元萃取剂体系明显加速.文中对这种动力学加速现象和动力学协同效应以及它们与热力学协同萃取的关系进行了讨论.     

伯胺N1923从硫酸介质中萃取La（Ⅲ）和Fe（Ⅲ）的动力学

伯胺N1923(以下简称RNH_2)是分离钍和稀土的有效萃取剂。N1923对铁(Ⅲ)和稀土(Ⅲ)萃取热力学的研究表明,在硫酸体系中加入PO_4~(3-),可使稀土(Ⅲ)和铁(Ⅲ)的分离系数增大,本文研究了N1923从硫酸介质中萃取稀土(Ⅲ)和铁(Ⅲ)的动力学性质,以推动N1923在稀土工业中的应用。 N1923由上海有机化学研究所提供,伯胺含量>99％,用等当量浓度的硫酸平衡得到实验     

超高效液相色谱-串联四极杆质谱法检测小型家电外壳中的六溴环十二烷

建立了加热回流萃取-超高效液相色谱-串联四极杆质谱检测小型家用电器中六溴环十二烷( Hexabromocyclododecane,HBCD)的方法.实验优化了电子电器类产品的前处理方法,以甲苯-甲醇(10∶1,V/V)为萃取剂,加热回流4h.萃取出的溶液经N2吹干,初始流动相复溶,涡旋、离心、过膜,经ACQUITYTMUPLC BEH C18色谱柱分离;以甲醇-乙腈(4∶1,V/V)-10 mmol/L醋酸铵为流动相,质谱的多反应监测模式(MRM)进行检测,HBCD的3种同分异构体在3 min内完全分开.该物质的检山限为0.014 mg/L:定量限为0.068 mg/L;标准曲线的线性范围为1.6～ 32.4 mg/L,线性相关系数大于0.996,萃取回收率为68.0％～75.2％.通过外标法定量,并将本方法应用于实际样品(电视机外壳、电子相框、电磁炉外壳等)的检测.     

伯胺N1923萃取钯(Ⅱ)的动力学研究

有关伯胺萃取钯(Ⅱ)的动力学研究,尚未见报道。本文用恒界面池搅拌法考察了N1923-正辛烷溶液从氯化物介质中萃取Pd(Ⅱ)时,诸因素的影响,用离子选择电极连续检测萃取过程中水相Pd(Ⅱ)浓度随时间的变化。实验试剂 N1923中国科学院上海有机化学研究所实验厂生产,经减压蒸馏,收集175-205℃/5-10Torr馏分,电位滴定法分析,每克N1923含3.535mmol伯胺,即平均分子量为283,含量>99.7%。0.200mol·dm~-3N1923的正辛烷溶液     

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.