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用分光光度法研究了2.6-二乙酰基吡啶缩二(氨基疏脲)与 Cu2+,Co2+,Ni2+,Zn2+的配位反应,用作图法和自编的LEMIT-S程序计算了配合物的组成,摩尔吸光系数和稳定常数,两法所得的结果基本一致,结果表明,在乙醇中Cu2+与配体daptsc形成Cu2(daptsc)和Cu(daptsc),二者在溶液中共存,而Cu2+在DMF中仅生成1:1配合物,其它金属离子在两种溶剂中均形成1:1型。在两种溶剂中lgβ11的顺序为:Zn > Cu > Ni > Co. 相似文献
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制备了由2,6—二乙酰吡啶和肼基硫代甲酸酯衍生的希夫碱C5H3N[CH=NNHC(S)XR]2(X=S,R=CH3、C6H5CH2;X=O,R=C6H5CH2).离析出类型为MC5H3N[CH=NN=C(S)XR]2(M=Co2+、Ni2+、Zn2+、Pb2+和Cd2+)的希夫碱配合物.配合物为元素分析、红外、可见—紫外光谱以及磁化率测量所表征.结果指出:上述希夫碱均为N3S2型五齿配体. 相似文献
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本文应用pH-电位法在T=25.0±0.1℃,I=0.5mol·l-1KNO3下测定了Cu2+与甘氨酸(glyH2),β-丙氨酸(β-alaH2),丙二酸(prodH2)和丁二酸(butadH2)等配体形成的配合稳定常数。简要分析了△logK值偏正的原因可能是分子内配体基团之间的相互作用。 相似文献
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双核Mo-Fe-S原子簇配合物[Fe(2,2′-bpy)3][S2MoS2FeCl2],是(Et4N)2MoS4、FeCl2和2,2′-联吡啶在乙腈中反应得到的结晶化合物.晶体属单斜晶系,空间群P21/c;a=9.328(3),b=26.788(2),c=13.764(3)Å;β=95.38(3)°;V=3424.2(11)Å3;Z=4;Dc=1.698g/cm3;F(000)=1752.晶体结构用直按法解出;经全矩阵最小二乘法修正,最后R=0.068,Rω=0.071(3933个I>3(σ)(I)的独立衍射).在晶体结构中配位阴离子[S2MoS2FeCl2]2-是排布在阳离子[Fe(2,2′-bpy)3]2+所形成的空腔中.它是以非统计分布的形式存在,从而较准确地测定了各项键参数.Mo…Fe距离为2.773(2)Å,Mo-Sb和Fe-Sb有大致相等的键长. 相似文献
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混合金属配合物MoS4Cu2(NC5H5)4的合成、晶体结构和成键特点 总被引:2,自引:0,他引:2
混合金属配合物MoS4Cu2(NC5H5)4(NC5H5=吡啶)的晶体属于三斜晶系P1空间群,晶胞参数:a=9.465(50),b=9.463(4),c=14.053(3)Å,α=95.16(3),β=84.89(3),γ=95.91(4)°,Z=2,V=1243(2)Å3;Mr=667.7,Dc=1.784g·cm-3.R因子为0.039,加权Rw因子为0.045.该配合物簇骼具有D2d对称性,Mo-Cu间距分别为2.638Å,2.663Å.端配体吡啶与金属原子Cu间的d-π*反馈在一定程度上增强了Mo—Cu间的相互作用. 相似文献
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溶液中N-乙酸基取代氮氧杂大环及其配合物稳定性研究 总被引:1,自引:0,他引:1
用pH电位滴定法在25℃,0.5mol·L-1KNO3水溶液中测定了三种大环化合物:H2L1(1,12-二氮杂-3,4:9,10-二苯并-5,8-二氧杂环十五烷-N,N'-二乙酸);H3L2(1,12,15-三氮杂-3,4:9,10-二苯并-5,8-二氧杂环十七烷-N,N',N″-三乙酸)和H2L3(1,15-二氮杂-3,4:12,13-二苯并-5,8,11-三氧杂环十八烷-N,N′-二乙酸)的逐级质子化常数.又测定了它们与Cu2+、Ni2+、Pb2+配合物的稳定常数,以及H2L3与镧系金属La3+、Pr3+、Nd3+、Eu3+、Sm3+、Gd3+、Dy3+、Yb3+配合物的稳定常数.讨论了三种大环化合物质子化的一般顺序及其与各种离子配位时稳定性选择规律.说明了影响配位稳定性的有关因素. 相似文献
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GHOLAM HOSSEIN ROUNAGHI RAZYEH SANAVI KHOSHNOOD 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(3-4):309-314
A series of competitive metal ion transport experiments have been performed. Each involved transport from an aqueous source phase across an organic membrane phase into an aqueous receiving phase. The source phase contained equimolar concentrations of cobalt(II), nickel(II), cupper(II), zinc(II), cadmium(II), silver(I) and lead(II) metal cations. The membrane phase incorporated ionophore, decyl-18-crown-6. The membrane solvents include: chloroform, dichloromethane, 1,2-dichloroethane, nitrobenzene and chloroform–nitrobenzene binary solvents. A good transport efficiency and selectivity of Pb2+ transport from aqueous solutions are observed in this investigation. The selectivity order for competitive bulk liquid membrane transport of the studied transition and post transition metal cations through chloroform is: Pb2+>Co2+>Ni2+>Ag+>Cd2+, but in the case of dichloromethane, 1,2-dichloroethane and nitrobenzene as liquid membranes, the selectivity sequences were found to be: Pb2+>Co2+>Cd2+>Cu2+>Ag+>Ni2+>Zn2+, Pb2+>Co2+>Ag+>Ni2+>Zn2+ and Pb2+>Co2+>Ni2+>Zn2+>Cd2+>Ag+, respectively. The transport rate of the metal cations in chloroform–nitrobenzene binary solvents is sensitive to the solvent composition. The transport processes were studied in absence and presence of the stearic acid and the results show that the sequence of selectivities and ion transport rates change in the presence of stearic acid. 相似文献
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Mahmood Payehghadr Akram Zamani Ali Reza Salehi Sadaghiani Mehdi Taghdiri 《Journal of inclusion phenomena and macrocyclic chemistry》2008,62(3-4):255-261
The complexation reaction between 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane ligand (Kryptofix5) and Zn2+, Ni2+, Co2+, Pb2+ and Cu2+ ions were studied conductometrically in acetonitrile solution. The formation constants of the resulting 1:1 complexes were calculated from the computer fitting of the molar conductance and absorbance measurements in various mole ratios. The enthalpy and entropy changes of the complexation reactions were derived from titration conductometry in acetonitrile at various temperatures. At 25 °C, the stability of the resulting complexes varied in the order Pb2+ > Zn2+ > Cu2+> Co2+> Ni2+. 相似文献
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Miraç Ocak Hakan Alp Halit Kantekin Hülya Karadeniz Ümmühan Ocak 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(1-2):17-24
Three new macrocyclic crown ether ligands containing nitrogen–oxygen donor atoms were designed and synthesized from 1,4-bis(2′-formylphenyl)-1,4-dioxabutane
and 4-nitro-o-phenylenediamine. Ion-pair extraction of metal picrates such as Ag+, Hg2+, Cd2+, Zn2+, Cu2+, Ni2+, Mn2+, Co2+, and Pb2+ from aqueous phase to the organic phase was carried out using the novel ligands. The solvent effect over the metal picrate
extractions was investigated at 25 ± 0.1 °C by using UV–visible spectrometry. The extractability and the values of the extraction
constants (log Kex) were determined for the extracted complexes. 相似文献
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《Analytical letters》2012,45(17):3074-3087
Abstract Insoluble porous solid, macrocyclic 22-membered ring, 1-oxa-6,9,12,15,18-pentaaza-2,22-disilacyclododocosane polysiloxane ligand system has been prepared by the reaction of a macro-silane agent with tetraethylorthosilicate. The macro-silane agent was prepared by the reaction of imino-bis(N-2-aminoethylacetamide) ligand with 3-iodopropyltrimethoxysilane in 1:3 molar ratio. The new prepared polysiloxane system exhibits variable potentials for the extraction of metal ions (Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Hg2+, and Pb2+) from aqueous solutions. The ligand system shows high capacity to extract silver, lead, and mercury. Chemisorption of the metal ions by the ligand system at the optimum conditions was found in the order Ag + > Pb2+ > Hg2+ > Cu2+ > Ni2+ > Fe3+ > Co2+ > Cd2+ > Zn2+. 相似文献
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ÜMMÜHAN OCAK HALIT KANTEKIN YAŞAR GÖK H. BASIR ŞENTÜRK 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(1-2):87-91
The selective liquid–liquid extraction of various transition metal cations from the aqueous phase to the organic phase was carried out using a 14-membered N2O2S2-macrobicycle. Metal picrates such as Pb2+, Co2+, Zn2+, Ni2+,Cu2+ and Cd2+ were used in this extraction studies. It was found that the ligand showed moderate selectivity towards Pb2+ only among the other metals. The extraction constant (log K
ex) was determined to be 13.8 for Pb2+ complex. 相似文献
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The extraction of ammine complexes of Cu2+, Cd2+, Ni2+, Co2+ and Zn2+ by synthesised manganese, nickel and zinc silicates has been studied at different pH and ionic concentrations in the external
solution. It has been found that the uptake of the metal ion Co2+, Cu2+ and Zn2+ increases with increase in pH of the external solution, attains a maximum and then decreases. However, the uptake for Cd2+ and Ni2+ increases continuously. The qA values of all the silicates increases with the increase in the concentration of the exchanging ion and its order for the
investigated metal ions is Ni2+ < Co2+ < Cd2+ < Zn2+ < Cu2+. 相似文献
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The formation and dissociation kinetics of the pentaco-ordinated Cu2+, Ni2+, Co2+ and Zn2+ complexes with 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane (4-MeCyclam-14) was studied by pH-stat techniques and spectrophotometrically. The rates of the reactions between 4-MeCyclam-14 and each of the four metal ions, although slower than normal complexations by a factor of 103?104, closely follow the order Cu2+ > Zn2+ > Co2+ > Ni2+, found for the rate of water exchange. This implies that beside water exchange an other constant factor plays an important role in the rate determing step. The dissociation of the pentaco-ordinated 4-MeCyclam-14 complexes is acid catalyzed. The limiting rate for acid dissociation is not reached even in 2.5M HNO3 in the case of Ni(4-MeCyclam-14)2+. From the formation and dissociation rates stability constants have been calculated, which do not show any macrocyclic effect. 相似文献
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The kinetics of the exchange between MnO or Mn3O4 and Co2+, Cu2+, Ni2+, or Zn2+ ions in solution, was determined by measuring the γ-activity of56Mn acquired by the solution after shaking with the neutron irradiated solid. The results indicated a fast exchange followed
by a slower apparently diffusion-controlled exchange. The exchange capacity increased in the series: Co2+<Ni2+<Cu2+=Zn2+ for MnO and Ni2+<Co2+<Zn2+<Cu2+ for Mn3O4. The trends could not be satisfactorily explained by the ionic radii or crystal field stabilisation-energies. In the case
of MnO, the results were discussed in terms of the estimated standard enthalpy change of the exchange reaction. 相似文献