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 109 毫秒
1.
配合物C30H58O4N2·Cu(Ⅱ)的合成与表征   总被引:6,自引:0,他引:6  
EDTA与金属离子络合时 ,一般只有二个羧基和两个N原子参加配位 ,另两个羧基没参加配位。EDTA二钠盐及其与金属的配合物均能溶于水 ,在有机溶剂中溶解性差不利于萃取。本文将十二烷基引入EDTA二钠分子 ,制备了配体N ,N′-二 (十二烷基 )乙二胺二乙酸二钠盐 ,它作为铜的萃取剂 ,萃取率高。用红外光谱、元素分析、核磁共振、紫外光谱及摩尔电导对其铜配合物进行了表征。1 实验部分1 1 主要仪器和试剂美国NICOLET360 -PT型红外光谱仪 ,KBr压片 ;岛津UV -紫外分光光度计 ;DDS - 1 2数字电导率仪 ;德国Bra…  相似文献   

2.
本文合成了11种稀土与α-萘乙酸的配合物。元素分析结果表明配合物的组成为RE(C12H9O2)3.2H2O(RE=La,Ce,Pr,Nd,Sm,Eu,Gd,Dy,Er,Yb,Y),并通过配合物的IR,UV,H-NMR,TG-DTA,XPS,磁化率,摩尔电导及溶解性的研究。  相似文献   

3.
合成了二苯并四氮杂[14]轮烯金属配合物TMTAANi(Ⅱ),TMTAACu(Ⅱ)和TMTAAV=O,通过TMTAAM(Ⅱ)分子中金属离子M(Ⅱ)对位碳原子上发生酰化反应,获得了十个酰化产物,用元素分析,IR,UV,1 ̄HNMR,(19) ̄FNMR和EPR等进行了表征。酰化反应的发生说明了这类金属配合物具有类芳香性,并为改善这类大环金属配合物的光-电性能提供了良好的途径。  相似文献   

4.
顺磁性聚酯金属配合物的合成及其驰豫性能的研究   总被引:2,自引:0,他引:2  
本文通过二乙三胺五乙酸(DTPA)或乙二胺四乙酸(EDTA)的双酸酐与二元醇或二元酚进行聚合反应,制备了两个系列共15种新的聚酯型大分子配体及其顺磁性金属配合物,用核磁、红外光谱以及元素分析表征了配体和配合物的结构。初步试验结果表明,与相应的小分子金属配合物相比,聚酯金属配合物具有较高的弛豫性能。  相似文献   

5.
建立了用高效毛细管区带电泳(CZE)分离Cu(Ⅱ),Zn(Ⅱ),Pb(Ⅱ)和Al(Ⅲ)-EDTA配合物的方法。对影响M-EDTA配合物分离的主要因素,如pH值、EDTA用量和阳离子表面活性剂用量等进行了讨论。采用控制加权可变步长单纯形算法动态寻优对影响[Al-EDTA]-形成的因素进行了优化。  相似文献   

6.
胡汉芳  王洪  丁天惠  傅若农 《色谱》1998,16(6):523-525
 建立了用高效毛细管区带电泳(CZE)分离Cu(Ⅱ),Zn(Ⅱ),Pb(Ⅱ)和Al(Ⅲ)-EDTA配合物的方法。对影响M-EDTA配合物分离的主要因素,如pH值、EDTA用量和阳离子表面活性剂用量等进行了讨论。采用控制加权可变步长单纯形算法动态寻优对影响[Al-EDTA]-形成的因素进行了优化。  相似文献   

7.
合成了标题卟啉配体及其钴、镍、铜、锌和铁的五种配合物.对它们进行了元素分析、UV、IR和荧光光谱等结构表征.用DTA、TG、DSC等手段研究了这些新化合物的热稳定性及热分解机理,实验结果与HMO方法计算的结果一致.  相似文献   

8.
以二氨基磺酸盐配合物合成了一系列主链上合金属元素(Ca,Ni,Co,Cu)的聚脲聚合物.用IR和1HNMR对其结构进行了表征,以TG-DTA研究了其热性能,并讨论了金属元素种类及其含量对聚脲聚合物溶液粘度的影响.  相似文献   

9.
合成了标题卟啉配体及其钴,镍,铜,锌和铁的五种配合物,对它们进行了元素分析,UV,IR和荧光光谱等结构表征。用DTA,TG,DSC等手段研究了这些新化合物的热稳定性及热分解机理,实验结果与HMO方法计算的结果一致。  相似文献   

10.
化合物Cs3Dy2Br9合成机理的相化学研究   总被引:1,自引:0,他引:1  
研究了CsBr与DyBr3在氢溴酸介质中反应的四元体系CsBr-DyBr3-HBr(13%)-H2O(25℃)相化学关系,发现了新物相5:3型化合物5CsBr.3DyBr.24H2O,并对其进行了X射线,DTG,DTA及偏光显镜等方面的研究。  相似文献   

11.
The synthesis and anion binding properties of a new class of calixpyrrole analogue, containing two carbazole subunits in lieu of two of the four acetone bridging elements normally found in calix[4]pyrrole, is described. The compound exists in a winglike structure in the solid state, as judged from single-crystal X-ray diffraction analyses of both the free system and the corresponding benzoate anion complex. Evidence for anion binding in dichloromethane solution was obtained from static fluorescent quenching experiments; these latter revealed a slight preference for acetate relative to other carboxylate anions (e.g., benzoate, oxalate, succinate), as well as various other anionic substrates (i.e., chloride and dihydrogen phosphate). No evidence of binding was observed in the case of bromide, nitrate, and hydrogen sulfate.  相似文献   

12.
A preorganized colorimetric tripodal thiourea receptor was synthesized in high yield utilizing a thiol-ene reaction as a primary step. The interaction of the receptor with dihydrogen phosphate, acetate, chloride, and fluoride anions was investigated using UV–vis. and 1H NMR spectroscopic titration techniques. The binding stoichiometry of the receptor with dihydrogen phosphate and acetate was found to be 1:2, and 1:1 with chloride and fluoride. The binding constants for the receptor and dihydrogen phosphate, acetate, chloride, and fluoride were determined using HypNMR2008 and HypSpec.  相似文献   

13.
利用同源模建和分子动力学模拟方法, 模建了两个新发现的α/β水解酶超家族成员W14和W15的三维结构, 并通过与α-醋酸萘酯的对接研究, 从理论上提出Gly82和Val13为形成“氧洞”的关键残基,有利于稳定水解过程中的带负电的过渡态, 以及其它对复合物形成起到重要作用的氨基酸残基.  相似文献   

14.
In order to take advantage of the peculiar mode of interaction consisting in the combination of hydrogen and coordination bonding displayed by the 7-azaindole core towards tetraacetate paddlewheel type complexes, a series of new derivatives, bearing peripheral interacting sites at the position 3, have been prepared and their self-assembly into dimeric H-bonded species was established in the solid state. Furthermore, the heterochelate mode of binding was exploited both in the solid state and in solution using [Rh(2)(OAc)(4)] paddlewheel to generate discrete capped complexes resulting from the coordination of the pyridyl nitrogen atom to the axial position of the Rh(ii) cations and hydrogen bonding between the pyrrolic NH and an oxygen atom of one of the equatorial acetate groups. The extension to infinite hybrid networks was achieved using derivatives bearing self complementary H-bond donor and acceptor groups such as a carboxylic moiety.  相似文献   

15.
We have determined the tail-tail dynamics and energetics of linear poly(dimethylsiloxane) (PDMS) polymers (M(n) = 3100; M(w)/M(n) = 1.07) that have been terminally labeled with pyrene (Py-PDMS-Py) in ethyl acetate between 255 and 323 K. The upper critical solution temperature (theta(u)) for the PDMS/ethyl acetate system is 278 K. The Py-PDMS-Py photophysics follow the Birks model at all of the temperatures studied. However, there is evidence for an increase in the local composition of PDMS surrounding the Py- residues in Py-PDMS-Py below the theta temperature. The recovered activation energy for Py-PDMS-Py tail-tail cyclization is the same as the activation energy for diffusion in ethyl acetate. The activation energy for cyclization is about fourfold larger in comparison to the barrier for PDMS internal backbone rotations. The estimated internal activation barrier for Py-PDMS-Py in ethyl acetate is in line with the internal barrier rotation for PDMS backbone rotation. The intramolecular excimer binding energy for Py-PDMS-Py in ethyl acetate is similar to the intermolecular pyrene excimer. In the ground state, the mean distance between the Py-PDMS-Py tail segments does not change over the temperature range studied. A comparison of these temperature-dependent Py-PDMS-Py/ethyl acetate results with previous results on Py-PDMS-Py in pure supercritical CO2 and CO2-dilated liquids shows that the addition of CO2 to the liquid phase offers the way to tune to Py-PDMS-Py tail-tail dynamics over the greatest range.  相似文献   

16.
The investigation of hydrolysis of p-nitrophenyl acetate (NPA) catalyzed by bovine serum albumin (BSA) proved that the initial rate in the steady state folows a Michaelis-Menten equation. In the use of D- and L-p-nitrophenyl α-methoxyphenlacetates (D- and L-NPMA's) as an enantiomeric ester, the L-enantiomer is hydrolyzed about three times faster than the D-enantiomer, mainly due to stronger binding of the former enantiomer by BSA.  相似文献   

17.
Interactions of drug candidates with the biomacromolecules of the synovial fluid affect drug targeting to the articular cartilage as well as clearance from the synovial space upon intra-articular administration. Hyaluronic acid (HA) and human serum albumin (HSA) are two main components existing in the synovial fluid. To this end, we investigated the affinity of seven cationic amino acid and dipeptide β-naphthylamide derivatives towards HA and HSA in order to shed light on possible relationships between physicochemical properties, in particular charge state, and biomacromolecular interactions to increase the joint residence time. Capillary electrophoresis frontal analysis was used for characterization of the binding of the derivatives to hyaluronic acid and HSA at 25 °C in acetate buffer (pH 4.65) and phosphate buffer (pH 7.40), respectively. Linear binding isotherms were observed for the ligand–hyaluronic acid interactions and the obtained binding constants ranged from 43 to 133 M?1. The average fraction of bound ligand towards hyaluronic acid increased with increasing the net charge of the ligands but was less than 67 % for all investigated ligands. The obtained binding constants of the ligands with HSA varied in the range of 103–106 M?1. The interactions of low-molecular weight derivatives with hyaluronic acid were highly dependent on the ligand charge state. This trend was not observed for the interactions with HSA. The obtained affinity data may provide useful information in the design of cartilage adhesive prodrugs with extended residence time in the synovial cavity.  相似文献   

18.
Previously, using acetate deuterated in the methyl hydrogen positions, we showed that acetate binds in close proximity to the Mn cluster/Y(.)(z) tyrosine dual spin complex in acetate-inhibited photosystem II (PSII) preparations exhibiting the "split" EPR signal arising from the S(2)-Y(.)(z) interaction [Force, D. A.; Randall, D. W.; Britt, R. D. Biochemistry 1997, 36, 12062-12070]. By using paramagnetic NO to quench the paramagnetism of Y(.)(z), we are able to observe the ESEEM spectrum of deuterated acetate interacting with only the Mn cluster. A good fit of the ESEEM data indicates two (2)H dipolar hyperfine couplings of 0.097 MHz and one of 0.190 MHz. Modeling of these dipolar interactions, using our "dangler" 3 + 1 model for the S(2)-state of the Mn cluster, reveals distances consistent with direct ligation of acetate to the Mn cluster. As acetate inhibition is competitive with the essential cofactor Cl(-), this suggests that Cl(-) ligates directly to the Mn cluster. The effect of acetate binding on the structure of the Mn cluster is investigated by comparing the Mn-histidine coupling in NO/acetate-treated PSII and untreated PSII using ESEEM. We find that the addition of acetate and NO does not affect the histidine ligation to the Mn cluster. We also investigate the ability of acetate to access Y(.)(z) in Mn-depleted PSII, a PSII preparation expected to be more solvent accessible than intact PSII. We detect no coupling between Y(.)(z) and acetate. We have previously shown that small alcohols such as methanol can ligate to the Mn cluster with ease, while larger alcohols such as 2-propanol, as well as DMSO, are excluded [Force, D. A.; Randall, D. W.; Lorigan, G. A.; Clemens, K. L.; Britt, R. D. J. Am. Chem. Soc. 1998, 120, 13321-13333]. We probe the effect of acetate binding on the ability of methanol and DMSO to bind to the Mn cluster. We find that methanol is able to bind to the Mn cluster in the presence of acetate. We detect no DMSO binding in the presence of acetate. Thus, acetate binding does not increase the affinity or accessibility for DMSO binding at the Mn cluster. We also explore the possibility that the acetate binding site is also a binding site for substrate water. By comparing the ratioed three-pulse ESEEM spectra of a control, untreated PSII sample in 50% D(2)O to an NO/acetate-treated PSII sample in 50% D(2)O, we find that the binding of acetate to the oxygen evolving complex of photosystem II displaces deuterons bound very closely to the Mn cluster.  相似文献   

19.
The anion binding properties of fluorinated calix[n]pyrroles (n = 4-6) in aprotic solvents (acetonitrile and DMSO) and modified reaction conditions allowing for the synthesis and isolation of the hitherto missing dodecafluorocalix[6]pyrrole from the condensation of 3,4-difluoro-1H-pyrrole and acetone are described. In acetonitrile solution containing 2% water, the association constants for the 1:1 binding interaction between octafluorocalix[4]pyrrole and chloride anion obtained with isothermal titration calorimetry (ITC) and (1)H NMR titration methods were found to match reasonably well. As compared to its nonfluorinated congener, octafluorocalix[4]pyrrole was found to display enhanced binding affinities for several representative anions in pure acetonitrile as judged from ITC analyses. Similar analyses of the fluorinated calix[n]pyrroles revealed an increase in the relative affinity for bromide over chloride with increasing macrocycle size, as manifest in a decrease in the binding ratio K(a(Cl))/K(a(Br)). Anion binding studies in the solid state, involving single-crystal X-ray diffraction analyses of the chloride and acetate anion complexes of octafluorocalix[4]pyrrole and decafluorocalix[5]pyrrole, respectively, confirmed the expected hydrogen bond interactions between the pyrrolic NH protons and the bound anions.  相似文献   

20.
A new series of indolocarbazole-quinoxalines (ICQ, receptors 6 and 7) are prepared and characterized for effective fluoride and acetate anion sensing. The new indole-based system has a highly flat rigid structure with a large pi system, and exhibits high binding affinity and sensitivity for acetate and fluoride anions. Receptors 6 and 7 give abundant and unique spectral features in dimethyl sulfoxide (DMSO). Both fluoride and acetate anions cause a bathochromic shift of the absorption peaks of receptor 7 in DMSO, whereas only fluoride anion results in a remarkable shift of the absorption peak of receptor 6 in DMSO. Receptors 6 and 7 can also operate as efficient colorimetric sensors for naked-eye detection of fluoride and acetate anions, and their combined use also offers a simple way for distinguishing these two anions by the naked-eye. The analysis of a Job's plot for the binding of receptor 7 and F(-), single crystal structures of 7.TBACl and 7.TBACH(3)COO confirm 1:1 binding stoichiometry. Notably, the ICQ system offers novel and excellent receptors for acetate anion both in solution and in crystalline solid through the formation of two hydrogen bonds.  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