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1.
本文研究了新水溶性5,10,15,20-四(4-甲氧基-3-磺酸苯基)卟啉[T(4-MOP)PS4]的反相高效液相色谱(HPLC)分离条件。采用ShimpackPREP-ODS半制备色谱柱,用含有10mmol/L四乙基碘化铵的乙腈-水(体积比25:75)为流动相,流速18mL/min,于418nm波长下检测。[T(4-MOP)PS4]与合成中生成的杂质组分完全分离。经此制备的卟啉纯度高,已成功地应用于自来水样中微量钴、锌、铜离子的HPLC测定中。  相似文献   

2.
ZSM—12沸石的合成   总被引:2,自引:0,他引:2  
在水热体系中以甲基三乙基碘化铵为结构导向剂合成了SiO2/Al2O3=32.2~∞的ZSM-12分子筛,XRD和IR证明它们具有MTW拓扑结构;并以SEM和DTA表征晶体形貌和热稳定性,考察了催化性能。  相似文献   

3.
反相离子对高效液相色谱法测定杀虫单   总被引:3,自引:0,他引:3  
用反相离子对色谱法测定了杀虫单原粉中杀虫单的含量,色谱柱为Spherisorb ODSI 250mm·4.0mmi.d.5μm。流动相为0.025mol/L磷酸二氢钾-0.005mol/L四乙基溴倾铵,检测波长242nm,在上条件下,杀虫单原粉中杀虫单与杂质完全分离,方法操作简便,快速准确,可用于原粉中杀虫单的分析。  相似文献   

4.
本文研究了土壤中SeO和SeO的提取并成功地用离子色谱进行分析。方法灵敏、简便,可用于土壤中微量SeO和SeO的同时测定,取5g于土样,其检测限分别为40和50ng/g。  相似文献   

5.
氟硅酸铵处理对γ-Al2O3负载NiW催化剂性质的影响   总被引:5,自引:0,他引:5  
应用IR,XPS,TPR,NO和CO2吸附及脉冲微反等技术研究了氟硅酸铵处理前后β-Al2O3及负载NiW催化剂的表面性质,探讨了其改性机理地催化剂活性相的影响,结果表明,经氟硅酸铵处理后,γ-Al2O3表面的不饱和四面体空位及其四配位Al^3+上的强碱性羟基均明显减少,改变了γ-Al2O3表面的酸碱性和Ni^2+在γ-Al2O3表面的分布,使NiO倾向分布于γ-Al2O3的八面体空位,过量的氟硅  相似文献   

6.
徐通敏  周天舒 《分析化学》1995,23(2):123-127
本文研究了Nafion化学修饰钨丝圆盘预富集-石墨炉原子吸收方法测定牛血超氧化物歧化酶中淳离态Cu^2+及Zn^2+的方法,并用GFAAS法直接测定SOD中铜、锌的总量,证实了牛血SOD中金属辅基铜、锌原子个数比为1:1;初步探讨了一定浓度的牛血SOD中Cu^2+,Zn^2+的表观离解平衡常数,为提高SOD的活性和稳定性的研究,提供了一种有效的方法。  相似文献   

7.
Ti/SnO2+Sb2O3/PbO2阳极的性能研究   总被引:13,自引:0,他引:13  
梁镇海  王森 《电化学》1995,1(4):456-460
以SEM、EDS和XRD研究Ti/SnO2+Sb2O3/PbO2阳极,测定该阳极在1mol/LH2SO4中的使用寿命及其电化学参数a,b,i0并用双位垒模型讨论了其动力学参数。结果表明该电极具有优良的电化学性能和较长的使用寿命。  相似文献   

8.
褪色光度法测定SO_3~(2-)的研究   总被引:1,自引:0,他引:1  
本文研究了SO2-3褪色碱蓝6B的反应,在pH5.2HAc-NaAc缓冲介质中,SO2-3浓度在0.39~12mg/L范围内符合比尔定律,仅Fe3+、Ni2+、Cr3+干扰测定,用于食品中SO2-3的测定,结果令人满意。  相似文献   

9.
臧二乐  梁树权 《应用化学》1995,12(3):107-108
磷钼酸四氢三铵的制备及其交换性能臧二乐,梁树权(北京农业大学应用化学系北京100094)(中国院学院化学研究所北京)关键词磷钼酸四氢三铵,制备,离子交换性能通式为M_nXY_(12)O_(40)·pH_2O(其中M为一价阳离子;X为P、As、Si、G...  相似文献   

10.
采用IR和XRD技术研究了B2O3/ZrO2催化剂的结构性质,用ICP-MS测定了样品中B2O3的含量,通过Hammet指示剂正丁胺滴定法测定了B2O3/ZrO2系列催化剂的表面酸性;研究了载体预处理温度对样品表面酸性和结构的影响,以及B2O3含量对样品催化性能的影响;比较了B2O3负载于ZrO2,Al2O3,SiO2,TiO2,MgO和HZSM-5上催化活性和目的产物选择性的差异,讨论了B2O3/ZrO2催化剂在气固相Beckmann重排反应中的作用特点  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.
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.  相似文献   

13.
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.  相似文献   

14.
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   

15.
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%).  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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   

19.
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   

20.
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   

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