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1.
偏最小二乘催化极谱法同时测定铂,钯,铑   总被引:6,自引:0,他引:6  
应用M273A电化学系统中的线性扫描技术,确定了0.75mol/LH2SO4-1.5%NH4Cl-2.8mmol/L(CH2)6N4-0.0025%N2H4.H2SO4为偏最小二乘极谱法同时测定Pt、Pd、Rh的最佳极谱体系。Pt、Pd、Rh的线性范围为3.2mg/L、0-15.0mg/L和0-1.0mg/L。模拟样品及实际样品的回收率在90.3-107.7%之间。  相似文献   

2.
X射线单晶衍射结果表明,三核镉配合物Cd3[CH3O(O)C6H3CH=NNHC(S)NH2]4·[CH3COO]2·1/2[CH3S(O)CH3]·2H2O为单斜晶系,空间群为C2/c,a=3.4214(4),b=1.1581(2),c=1.7932(5)nm,β=119.76(1)°,V=6.168nm3,Mr=1427.43,Z=4,Dc=1.54g/cm3,μ=12.48cm(-1),F(000)=2860,最后偏离因子R=0.066.  相似文献   

3.
微分电位溶出法测定人发中铜铜镉锌的研究   总被引:5,自引:0,他引:5  
本文报道了0.0025mol.L^-1HCl-0.2mol.L^-1NH4Cl底液中连续测定人发中铜、铅、镉、锌的微分电位溶出法。四元素峰电位分别为-0.20V,-0.46V,-0.67V,-1.02V(SCE),峰形好,灵敏度高,干扰少,测定发样相对标准偏差≤4.3%,回收率为97.6%-104.6%。并对HNO3-HClO4和NHO3-H2O2消化发样进行了比较。  相似文献   

4.
本文报道了0.0025mol·L ̄(-1)HCl-0.2mol·L ̄(-1)NH_(4)Cl底液中连续测定人发中铜、铅、镉、锌的微分电位溶出法。四元素峰电位分别为-0.20V,-0.46V,-0.67V,一1.02V(SCE),峰形好,灵敏度高,干扰少,测定发样相对标准偏差≤4.3%,回收率为97.6%~104.6%。并对HNO_3-HClO_4和HNO_(3)H_(2)O_2消化发样进行了比较。  相似文献   

5.
制备了4-CH3SC6H4NH2(MMA)插层的α-Zr9HPO4)2.H2O,研究了不同实验条件下MMA的插层特性,发现插层反应与MMA和α-ZrP摩尔比R有关;(1)当R〉2时,有插层产物相产生,但是即使在MMA大大过量的条件下,仍然有部分α-ZrP颗粒大小等有关;插层产物的层间距约为2.36nm,,层间距的大小不随反应物浓度,温度等条件变化。  相似文献   

6.
在0.2mol/LNaOH-0.04mol/LH3PO4-0.02mol/L(NH4)2SO4-0.04mol/LCH3COOH溶液中,精氨酸(Arg)在苯甲醛存在下产生一灵敏的吸附波。实验证明电活性物质为α-苯亚甲基精氨酸,其电极反应机理是分子内α->C=N基团被还原为亚胺。用该吸附波可在1×10(-3)~2×10(-6)mol/L范围内分析蛋白质中的Arg。  相似文献   

7.
过硫酸钾存在下人血清白蛋白的极谱平行催化氢波及其应用   总被引:10,自引:0,他引:10  
报道 K2S2O8存在下人血清白蛋白(HSA)的极谱平行催化氢波。在 0.4 mol/L NH3-NH4Cl(pH 8.58)-0.01 mol/L K2s2O8支持电解质中,HSA产生一个平行催化氢波,峰电位为-1.85 V(vsAg/AgCl)。该平行催化氢波二阶导数峰电流与 HSA浓度在 2.6 × 10-9~9.6 × 10-9mol/L范围呈线性关系。用于人血清样和尿样中HSA的测定,结果满意。  相似文献   

8.
通过模拟结构因子计算将「(C4H9)4N」「Sc(NCS)6」.3.5H2O的空间群从正交晶系的pcab修正为立方晶系的pa3.将Sc(C17H13N2O2)3和「(H2O)10(OH)2Sc2」(C6H5SO3)4.4H2O从P1修正为C2/c。还将「Sc(NO3)3(H2O)3」.18-Crown-6的Pna21修正为Pnma。  相似文献   

9.
王长凤  刘秋田 《结构化学》1996,15(6):495-498
4-氨基-3,5-二甲基-1,2,4-三唑与水杨醛缩合形成4-(邻羟苯基亚甲基)-亚胺-03,5-二甲基-1,2,4-三唑Schiff碱(SATZ),该Schiff碱与Cu(ClO4)2.6H2O形成配合物Cu(satz)2.6H2O,分子式为C22H22CuN8O2.6H2O。  相似文献   

10.
NH4HCO3对氧化铝孔结构的影响   总被引:15,自引:0,他引:15  
NaAlO2溶液和CO2在低温下成胶,生成的沉淀为无定形氢氧化铝,拟薄水铝石或三水氧化铝;加入一定量的NH4HCO3,控制一定的时间,温度和压力,氢氧化铝与NH4HCO3作用生成片钠铝石NH4Al(OH)2CO3,经高温焙烧后可制香孔容为0.6-1.5ml/g的大孔容氧化铝。  相似文献   

11.
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%.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

18.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

19.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

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