首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
若干含多硫基的配合物的合成方法及结构特征   总被引:1,自引:0,他引:1  
本文综述了近年来我们合成的十二种多硫基的配合物,这些配合物含有S^2-2,S^2-4,S^2-5,S^2-6,S^2-7等多硫革配体,总结了这些配合物中的金属配位构型,比较了各种多硫基的S-S键长及有关键角,归纳了配合物外光谱,并阐述了其中几个配合物与NH2NH2的反应性能。  相似文献   

2.
在25±0.1℃,I=0.1mol·dm-3KNO3条件下,应用pH法测定了水杨醛缩α-氨基酸的酸离解常数及它们与Mn(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Zn(Ⅱ)生成的二元配合物的稳定常数.结果表明,对于同一种配体,配合物的稳定性均符合金属离子的欧文—威廉序;对于同一种金属离子,在配合物稳定性与配体的碱性之间均存在良好的直线自由能关系.  相似文献   

3.
报道了配体N-(二茂铁基甲基)-1,4,7-氮杂-9-冠-3(L1)和N-(二茂钌基甲基)-1,4,7-氮杂-9-冠-3(L2)的Co(Ⅲ)和Fe(Ⅲ)配合物1-4的合成及电化学性质,配合物「Co(Ⅲ)(L1)2(AcO)2(OH)」(ClO4)(I)2(1)的晶体结构显示这些配合物具有线型排列的四金属中心结构,电化学研究表明:在这些配合物中,客体金属离子通过分子片断的电子传递作用使二茂金属的金属  相似文献   

4.
报道了2个取代三联吡啶配体(4′-苯基-2,2′:6′,2″-三联吡啶(L1)和4′-二茂铁基-2,2′:6′,2″-三联吡啶(L2)的Co(Ⅱ)配合物(Co(Ⅱ)(L1)2)(ClO4)2.4CH3CN(1)和(Co(Ⅱ)(L2)2)(ClO4)2H2O(2)的合成及配体L2的配合物1和配合物2的晶体结构,电化学研究表明:在配合物2中,由于Co^2+的作用,二茂铁基的氧化电位较配体L2中的二茂铁  相似文献   

5.
报道了一种新的以三(2-吡啶甲基)甲烷为配体,以铑为主催化活性中心,并辅以其它金属为辅助催化的双金属配合物该配合物在相对温和的条件下,可迅速催化甲醇羰基化为醋酸,及醋酸甲酯羰基化为醋酐。实验结果证明,第二种金属的引入提高了配合物的催化活性,这种催化活性的提高因第二种金属的不同而有所差异。另外,根据配体的结构阐述了其对羰基化反应的作用机理。  相似文献   

6.
利用双齿膦配体1,1-双(二苯基膦)甲烷和1,2-双(二苯基膦)乙烷的还原性以及硝酸配体的易变特性,通过配体还原反应和配体取代反应,于甲醇溶剂中,在dppm和dbbe的存在下,合成了两个双核铜(I)配合物[Cu(dppm)(L)]]2(L分别为BH4和CIO4)和两个单核铜(I)配合物[Cu(dppe)(L)](L分别为BH4和CIO4)。本文又采用两种不同方法合成了两个合成了两个混配铜Ⅱ)配合物  相似文献   

7.
吡啶二甲酸类配体-EDTA-铽三元配合物的荧光性能   总被引:8,自引:1,他引:7  
对几种吡啶-2,6-二甲酸类配体与EDTA、铽的三元配合物在溶液中的荧光性能进行了研究,溶液PH值和溶剂效应对体系荧光的影响也分别进行了探讨。4-甲氧基吡啶-2,6-二甲酸和4-乙氧基吡啶-2,6-二甲酸等配体在这种三元体系中的敏化性能比常用的吡啶-2,6-二甲酸好,其中4-乙酰氨基吡啶-2,6-二甲酸特别优异。不论在二元配合物系还是在三元配合物体系中,均具有发光强度大、寿命长的特点。  相似文献   

8.
合成了咪唑基尾式卟啉-5-邻[4-(1-咪唑基)丁氧基]苯基-10,15,20-三苯基卟啉及其铁(Ⅲ)配合物。以元素分析,质谱,^1 H NMR,IR和紫外可见吸收光谱等进行了表征,初步研究了在氯仿和苯中某些含氮配体与铁(Ⅲ)配合物的轴向配位性质,表明,Fe(Ⅲ)Cl通常与含氮配体生成低自旋的六配位加合物,但在苯溶液中与咪唑作用时,一定条件下还能生成稳定的高自旋五配位加合物。  相似文献   

9.
金属有机配合物的非线性光学特性   总被引:4,自引:1,他引:4  
从过渡金属有机配合物的中心金属、配体和几何结构的多样性、多变的金属氧化态和金属与配体的电子供-受作用评述了金属有机配合物的二阶、三阶非线性光学效应的分子结构特征和最新进展。参考文献26篇。  相似文献   

10.
TTF·M(dmit)2型电荷转移配合物的合成及其拉曼光谱   总被引:2,自引:0,他引:2  
合成了8种四硫富瓦烯·二-(1,3-二硫杂环戊-4-烯-2-硫酮-4,5-二巯基)金属(缩写为TTF·M(dmit)-2)电荷转移配合物,其中7种配合物为首次合成,拉曼光谱的研究结果表明,对同一种电子受体,电子给体的还原电势Ep越小,配合物的电荷转移度ρ值越大。  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
20.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号