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1.
大环金属配合物具有较高的热力学稳定性和动力学惰性,可作为药物输送体系、肿瘤诊断、核磁共振成像增强剂等。大环化学的研究将对生命科学的发展起推动作用。大环四胺配体5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂不十四烷(简记为teta)近年来引起了广泛的关注,已有一些teta的配合物被陆续报道。本文报道配合物Cu(teta)(NO3)2的合成与晶体结构。  相似文献   

2.
自从1968年Jager合成第一个四氮[14]大环席夫碱配合物以来[1],四氮大环席夫碱配合物的研究受到人们很大的关注.这类配体与天然卟啉环非常相似,对小分子如O2、CO、CO2等均有较强的键联能力,对于研究生物体内的金属蛋白质及酶有着重要的意义[2,3].].另外,这类配合物具有作为催化剂、萃取剂、导体等潜在的应用价值.  相似文献   

3.
包结物[H2(teta)]2+·2Cl-·3H2O的合成与结构研究   总被引:2,自引:0,他引:2  
大环化合物在生命和材料科学中很重要[1,2]。大环四胺配体5,7,7,12,14,14 六甲基 1,4,8,11 四氮杂环十四烷(teta)近年来引起了广泛关注[3,4]。我们合成了化合物[H2(teta)]2+·2Cl-·3H2O,测定了晶体结构。1 实验部分1.1 [H2(teta)]2+·2Cl-·3H2O的合成[5]将5mL0 4mmolHCl水溶液缓慢加入teta·2H2O(0 0641g,0 2mmol)的5mL甲醇溶液。连续搅拌半小时后过滤,无色滤液在室温下放置两天后长出淡黄色块状晶体。元素分析(计算值)%:C,47 58(46 71);H,10 53(10 78);N,13 68(13 62).IR(cm 1):3331(vs),3231(s),3186(vs),2973(s),2876(s)…  相似文献   

4.
四氮杂大环配合物是生物体内一些金属酶结构单元的模拟物,四氮杂大环铜和镍的配合物可以催化化学振荡反应。近年来,此类反应被广泛地研究[1~4]。目前已报道的作为化学振荡反应催化剂的四氮杂大环配合物的配体都是单环。我们发现一种双四氮杂大环镍(Ⅱ)配合物Ni2L(ClO4)4[L为双(11,13二甲基1,4,7,10四氮杂10,13环十三二烯12亚甲基)]可以作为化学振荡反应的催化剂,本文研究了Ni2L(ClO4)4催化NaBrO3CH2(COOH)2(MA)H3PO4体系的化学振荡反应。1实验部分实验试剂:丙二酸…  相似文献   

5.
利用1HNMR技术以及单晶X衍射技术考察对称四甲基取代六元瓜环(TMeQ[6])与几种1,ω-亚烷基吡啶阳离子(ω=2,4,6,8,10)客体的相互作用.在这些包结配合物中,TMeQ[6]的端口效应以及空腔效应同时存在,其主客体作用模式随着客体亚烷基碳链长短不一而各不相同.对于客体1,2-二乙基吡啶(Edpy),TMeQ[6]包结Edpy的带正电荷的吡啶环部分,形成一不对称的包结配合物;对于客体1,4-二丁基吡啶(Bdpy),TMeQ[6]选择性包结Bdpy的吡啶环部分或烷基部分存在竞争作用和快速交换;而具有较长碳链的客体1,6-二己基吡啶(Hdpy)和1,8-二丁庚基吡啶(Odpy)与TMeQ[6]通过空腔的疏水作用以及外部的离子-偶极作用形成稳定的类轮烷包结配合物;客体1,10-二癸基吡啶(Ddpy)的两个吡啶环分别被两个TMeQ[6]包结形成哑铃型的包结配合物.  相似文献   

6.
利用^1HNMR技术以及单晶X衍射技术考察对称四甲基取代六元瓜环(TMeQ[6])与几种1,ω-亚烷基吡啶阳离子(ω=2,4,6,8,10)客体的相互作用.在这些包结配合物中,TMeQ[6]的端口效应以及空腔效应同时存在,其主客体作用模式随着客体亚烷基碳链长短不一而各不相同.对于客体1,2-二乙基吡啶(Edpy),TMeQ[6]包结Edpy的带正电荷的吡啶环部分,形成一不对称的包结配合物;对于客体1,4-二丁基吡啶(Bdpy),TMeQ[6]选择性包结Bdpy的吡啶环部分或烷基部分存在竞争作用和快速交换;而具有较长碳链的客体1,6-二己基吡啶(Hdpy)和1,8-二丁庚基吡啶(Odpy)与TMeQ[6]通过空腔的疏水作用以及外部的离子-偶极作用形成稳定的类轮烷包结配合物;客体1,10-二癸基吡啶(Ddpy)的两个吡啶环分别被两个TMeQ[6]包结形成哑铃型的包结配合物.  相似文献   

7.
140Cu/MCM-41和14T2Cu/MCM-41的制备与表征   总被引:1,自引:0,他引:1  
二氧四胺大环和取代二氧四胺大环化合物兼有大环氮杂冠醚和低聚肽的性质,能和很多过渡金属离子(Cu2+,Ni2+,Mn2+,Co2+等)形成具有特殊功能的配合物.如十四元二氧四胺大环Co(Ⅱ)配合物在-70℃加入过量的咪唑或吡唑后.  相似文献   

8.
配位化学中的直线自由能关系(XIX)   总被引:2,自引:0,他引:2  
前文[1]曾报导了侧基二氧四胺大环配体的合成及表征.与普通配合物相比,大环多胺配合物具有较高的稳定性及惰性和奇特的空间构型,其过渡金属配合物具有特殊的性质和用途,如作酶的模型、氧的载体等.铜(Ⅱ)配合物可作超氧歧化酶(SOD)的模型,超氧离子是人体内的氧代谢产物,它在体内过量积累会引起多种疾病,超氧歧化酶对超氧离子起催化歧化作用,以维持机体的正常运行间,故这种大环多胺Cu(Ⅱ)配合物具有重要的生物功能及广阔的应用前景.本文研究了四种带侧基二氧四胺大环配体-5-取代邻菲罗啉(5-Xphen;L1)铜(Ⅱ)三元配合…  相似文献   

9.
合成和表征了四个新的大环上含有草酰胺桥基的双核配合物[Cu(μ-L  相似文献   

10.
烯烃的双键可以与金属钌、铑、钯、铂、镍等发生配位形成配合物。目前,已有大量的手性双烯烃-金属配合物、手性有机膦烯烃-金属配合物、手性有机胺烯烃-金属配合物被合成出来。烯烃-金属配合物被广泛用于催化不对称1,4-加成反应中,并取得了较好的产率和ee值。另外,烯烃-金属配合物也被用于催化不对称[4+2]环加成反应及其他关环反应。  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.
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   

13.
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   

14.
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   

15.
16.
《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   

17.
Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.  相似文献   

18.
A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.  相似文献   

19.
A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).  相似文献   

20.
Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO4 oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.  相似文献   

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