共查询到20条相似文献,搜索用时 12 毫秒
1.
《Journal of Coordination Chemistry》2012,65(1-2):47-53
Abstract The equilibria between gallium(III) ion and selected hydroxyaromatic and dihydroxyaromatic ligands at 25°C, μ=0.100 M (KNO3) have been determined. Potentiometric measurements on 1:1, 2:1, and 3:1 molar ratios of ligand to Ga(III) have been made as a function of degree of neutralization over the entire accessible ?log [H+] scale. Calculations were carried out so as to take account of competing hydrolytic reactions, and formation constants of gallium(III) with chromotropic acid, 8-hydroxyquinoline-5-sulfonic acid, 5-sulfosalicylic acid, and 1,2-dihydroxy-benzene-3,5-disulfonic acid were obtained. Stable hydroxo chelates do not form under the reaction conditions employed. The protonation constants of the ligands and the formation constants of the gallium chelates are discussed and compared with previously published work on these gallium chelates and on chelates of “analogous” metal ions such as those of Fe(III) and A1(III). 相似文献
2.
SOLVATION OF ALUMINIUM(III) AND IRON(III) COMPLEXES OF HYDROXAMATE LIGANDS IN ALCOHOL-WATER MIXTURES
《Journal of Coordination Chemistry》2012,65(1-2):65-71
Abstract Solubilities and derived transfer chemical potential trends are reported for several tris(hydroxamato)-aluminium(III) and iron(III) complexes in methanol-water and in t-butylalcohol-water solvent mixtures. These trends are discussed in terms of hydrophilic and hydrophobic characteristics of the peripheries of these complexes. 相似文献
3.
《Journal of Coordination Chemistry》2012,65(1):37-41
Abstract Anhydrous vanadium trichloride reacts with azoles in low concentrated ethyl alcohol solution of V(III) to produce 1:1 electrolytic complexes of the type [V (azole)4Cl2]+. Studies of the visible spectra of all the above complexes demonstrate that the vanadium(III) is octahedrally co-ordinated. The room temperature magnetic moments of the complexes (~ 2.8 B.M.) are consistant with the presence of two unpaired electrons per vanadium atom. At higher concn. of V(III) the polynuclear violet-red complexes probably are formed. 相似文献
4.
《Journal of Coordination Chemistry》2012,65(1-4):221-232
Abstract Dedicated to Professor Arthur Martell on the occasion of his seventy fifth birthday. The complexes of In(III) and Ga(III) with a variety of nitrogen donor ligands were studied in aqueous solution by glass electrode potentiometry at 25°C in 0.1 M NaNO3. The ligands were 2-aminomethylpyri-dine (AMPY), ethylenediamine (EN), N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine (THPED), and N,N-bis(2-hydroxyethyl)glycine (BICIN). A variety of mixed ligand complexes of the MLOH type were detected with many of the above ligands as L. The logK1 values obtained were with Ga(III) 8.40 (AMPY), 7.94 (THPED) 12.72 (EN), and In(III) 7.6 (AMPY), 8.20 (THPED), and 7.06 (BICIN). These formation constants are discussed in relation to previous predictions that In(III) and Ga(III) would have a substantial chemistry with nitrogen donor ligands. Of particular interest is the Ga(III) system with EN, where a very stable Ga(EN)3+ complex is formed, but no higher complexes except for hydrolyzed species such as Ga(EN)OH2+ and Ga(EN)(OH)2 +. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(4):355-363
Abstract Meridional geometrical isomers of cobalt(III) complexes with sarcosine (N-methylglycine) and tetradentate ligands edda (ethylenediamine-N,N′-diacetate ion), eddp (ethylenediamine-N,N′-di-3-propionate ion) and 1,3-pdda (1,3-propylenediamine-N,N′-diacetate ion) have been prepared. The edda and eddp cobalt(III) complexes were made by the reaction of sarcosine and sodium ethylenediamine-N,N′-diacetato(carbonato)cobaltate(III), and sodium uns-cis-(ethylenediamine-N,N′-di-3-propionato)(carbonato)cobaltate(III) dihydrate, respectively. The previously synthesized pdda-cobalt(III) complex with sarcosine was obtained by a new route by direct synthesis of cobalt(II) chloride hexahydrate with sarcosine and 1,3-pdda in the presents of lead(IV) oxide. Complexes were isolated chromatographically and characterized by elemental analysis, electron absorption spectra, infrared spectra and 1H NMR spectroscopy. 相似文献
6.
基于铁和锰的双核配合物在生物氧化还原过程中的重要作用及在化学的氧化还原过程中可能做为催化剂的应用前景,本文合成了两个新的以氯醌酸二价阴离子为桥联配体的Fe(Ⅲ)双核和Mn(Ⅱ)双核配合物:[Fe_2(phen)_4(μ-CA)](ClO_4)_4·2H_2O(1)和[Mn_2(phen)_4(μ-CA)](ClO_4)_2·3H_2O(2)(phen=1,10菲咯啉;CA=氯醌酸二价阴离子)。经元素分析、IR、电子光谱及磁性等测定,对两配合物进行了表征。 相似文献
7.
《Journal of Coordination Chemistry》2012,65(4):211-214
Abstract Binuclear iron(III) complexes with salicylate ligands, Na2 [Fe2 (C7 H4 O3)4 (H2O)2] and Na4 [Fe2 (C7H4O3)4 (OH)2], crystallize out in the pH range 1–5 and pH 5.5, respectively, from solutions containing iron(III) chloride and a slightly more than two molar proportion of sodium salicylate. Infrared and Mössbauer spectral results and magnetic moment data indicate the presence of non-linear Fe—O—Fe bridge bonds. Evidently two salicylate ligands form bridges between the two iron(III) ions through phenolic oxygen. Mössbauer spectral results indicate the absence of bridging salicylate ligands in solutions of the complex prepared by mixing iron(III) chloride and two to three-fold molar excess of salicylate ions; only mononuclear complexes exist in such solutions. 相似文献
8.
《Journal of Coordination Chemistry》2012,65(1-2):7-12
Abstract The trianionic binucleating ligands formally derived from the condensation products of S-n-octyldithiocarbazate with either 2-hydroxy- or 2-mercapto-5-methylisophthalaldehyde (hereafter (L″)3- and L3- respectively) gave the binuclear complexes L″Ni2 (CH3 O), L″Ni2 (C6 H5 CH2 O), LNi2 (C3 H3 N2), LCu2 (C3 H3 N2) and LNi2 (SR) where R=C8H1 7 of CH3.C6 H4 and C3 H3 N2 ?=the pyrazolate anion. These complexes were soluble in chloroform and 1H n.m.r. data for some of them are presented. There was no evidence for significant magnetic exchange within LCu2 (C3 H3 N2). Attempts to generate LNi2 (X) where X?=Cl?, Br? or I? gave L2 Ni3 in which L3- fails to impose the intended molecular arrangement. Attempts to generate L(Pd(II))2 (X) unexpectedly gave materials containing additional palladium, i.e. LPd4 (CH3 CO2) and LPd4 (C3 H3 N2). 相似文献
9.
《Journal of Coordination Chemistry》2012,65(4):335-345
Abstract The behavior of thiosalicylic acid (H2TSA) and 6-mercaptopurine (MP) with vanadyl(IV) cation has been studied in solution at different ligand-to-metal ratios and pH values. The preparation and characterization of VO/TSA(I) and VO/MP(II) complexes in the solid state is reported. The chemical environment of V in (I) is consistent with S and O atoms of TSA and two hydroxy bridges between two metal centers. The nearest neighbor atoms to V in (II) are S and N provided by the ligand and O atoms from hydroxyl groups. These results have been supported by physicochemical studies. 相似文献
10.
《Journal of Coordination Chemistry》2012,65(1-2):101-105
Abstract The ESR parameters were determined for copper(II) complexes with various 14-, 15- and 16-membered N4-macrocyclic ligands. Of these ESR parameters g‖ has the most simple relation to the covalency of the coordination bonds in the present compounds, i.e., the smaller the g‖ value the larger the covalency. The order of covalencies derived from the g‖ values nicely matches with that supposed from the size of macrocyclic rings and the charge of the ligands. The approach to the estimation of covalency of the coordination bonds by use of copper hyperfine coupling constant was examined, but it was found that this approach gives rather unreliable results for the present compounds. 相似文献
11.
Novel aluminum(III)- and zirconium(IV)-tetraphenylporhyrin (TPP) derivatives are examined as fluoride-selective ionophores for preparing polymer membrane-based ion-selective electrodes (ISEs). The influence of t-butyl- or dichloro-phenyl ring substituents as well as the nature of the metal ion center (Al(III) versus Zr(IV)) on the anion complexation constants of TPP derivative ionophores are reported. The anion binding stability constants of the ionophores are characterized by the so-called “sandwich membrane” method. All of the metalloporphyrins examined form their strongest anion complexes with fluoride. The influence of plasticizer as well as the type of lipophilic ionic site additive and their amounts in the sensing membrane are discussed. It is shown that membrane electrodes formulated with the metalloporphyrin derivatives and appropriate anionic or cationic additives exhibit enhanced potentiometric response toward fluoride over all other anions tested. Since selectivity toward fluoride is enhanced in the presence of both anionic and cationic additives, the metalloporphyrins can function as either charged or neutral carriers within the organic membrane phase. In contrast to previously reported fluoride-selective polymeric membrane electrodes based on metalloporphyrins, nernstian or near-nernstian (−51.2 to −60.1 mV decade−1) as well as rapid (t < 80 s) and fully reversible potentiometric fluoride responses are observed. Moreover, use of aluminum(III)-t-butyltetraphenylporphyrin as the ionophore provides fluoride sensors with prolonged (7 months) functional lifetime. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(1-2):157-166
Abstract Complex formation between copper(II) and 3-amino-3-phosphonoglutaric acid (Apga), an ambidentate aminophosphonate or citric acid derivative, was studied in aqueous solution by pH-potentiometry and EPR and electronic spectroscopy. Complexation with the parent molecules citric acid and tricarballylic acid was reinvestigated. The stoichiometries and stability constants of the complexes formed in these systems were determined at 25°C at an ionic strength of 0.20 mol dm?3 (KCl). Stability constant data and spectroscopic results revealed that in the acidic pH range Apga behaves as a citric acid derivative, forming the phosphonate-bridged dimeric species Cu2A2H2, while in the basic pH range, with decreasing proton competition at the amino binding site, it rearranges to yield mononuclear complexes involving aminophosphonate-like (NH2, PO3 2-, CO2) coordination. 相似文献
13.
《Journal of Coordination Chemistry》2012,65(3):151-156
Abstract The V(III)-pyrazine system was examined spectroscopically in the isoamyl alcohol solution. An unstable, violet-red, binuclear vanadium(III) complex [V2(pyraz)Cl4]2+ was found to be formed. On exposure to air it was slowly converted into a sparingly soluble green vanadium(IV) compound, [VO(pyraz)OH]Cl.H2O. This compound was examined by the analytical, spectroscopic (electronic and infra-red spectra) and magnetic methods. 相似文献
14.
《Journal of Coordination Chemistry》2012,65(4):477-486
Abstract The structures of isomorphic Tb(III) and Ho(III) complexes with 2,6-dihydroxybenzoic acid of formula [Tb(C7H5O4] 2H2O and [Ho(C7H5O4)3 4H2O] 2H2O has been determined by X-ray diffraction and refined to a residual R = 0.030 for 5376 observed reflections and R = 0.0284 for 5660 observed reflections, for Tb(III) and Ho(III) complexes, respectively. Crystals are triclinic, space group P1 with a= 10.748(2), b=11.309(2), c = 12.452(2)Å, α = 82.28(3), ? = 73.05(5), γ = 68.27(3)° for Tb(III) and a= 10.731(2), b=11.269(2), c = 12.436(2)Å, α = 82.25(3), β = 72.92(3), γ = 68.46(3)° for Ho(III). In the structure of these monomelic complexes the metal ions are coordinated by oxygen atoms of one bidentate chelating and two monodentate carboxylate groups and four molecules of water. Tb-O distances are in the range 2.323(3)-2.506(3) Å and Ho-0 2.297(3)-2.486(3) Å. The crystal structure, consisting of discrete units of neutral complexes with two molecules of water of crystallization is stabilized by intra-and intermolecular hydrogen bonds. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(1-3):51-64
Abstract The new 1,2-dithiolene, 1,4-butanediyldithioethylene-1,2-dithiolate, has been isolated. In addition, new monoanionic bis-complexes with nickel and copper have been prepared and isolated. The formal Ni(III) complex crystallizes in the orthorombic space group, Pbca, with a = 9.762(9), b = 12.53(2), and c = 23.166(3) Å, with 4 molecules in the unit cell. The structure was refined to an R = 9.01% (Rw = 8.95%). The formal Cu(III) complex crystallizes in the monoclinic space group, C2/c, with a = 25.567(6), b = 8.011(3), c = 14.504(3) Å, and β = 106.17(2)° with 4 molecules in the unit cell. The structure refined to R = 4.2% with R w = 4.3%. Comparisons to similar 1,2-dithiolenes suggest this ligand produces only modest structural and electronic differences when compared to the 1,3-propanediyldithioethylene-1,2-dithiolate complexes. The oxidation (to a neutral complex) and reduction (to a dianion) for the Ni(III) and Cu(III) complexes show large differences from those of maleonitriledithiolate. Other physical data are presented as well. 相似文献
16.
Vanloot P Branger C Margaillan A Brach-Papa C Boudenne JL Coulomb B 《Analytical and bioanalytical chemistry》2007,389(5):1595-1602
A new analytical method was developed for on-line monitoring of residual coagulants (aluminium and iron salts) in potable
water. The determination was based on a sequential procedure coupling an extraction/enrichment step of the analytes onto a
modified resin and a spectrophotometric measurement of a surfactant-sensitized binary complex formed between eluted analytes
and Chrome Azurol S. The optimization of the solid phase extraction was performed using factorial design and a Doehlert matrix
considering six variables: sample percolation rate, sample metal concentration, flow-through sample volume (all three directly
linked to the extraction step), elution flow rate, concentration and volume of eluent (all three directly linked to the elution
step). A specific reagent was elaborated for sensitive and specific spectrophotometric determination of Al(III) and Fe(III),
by optimizing surfactant and ligand concentrations and buffer composition. The whole procedure was automated by a multisyringe
flow injection analysis (MSFIA) system. Detection limits of 4.9 and 5.6 μg L−1 were obtained for Al(III) and Fe(III) determination , respectively, and the linear calibration graph up to 300 μg L−1 (both for Al(III) and Fe(III)) was well adapted to the monitoring of drinking water quality. The system was successfully
applied to the on-site determination of Al(III) and Fe(III) at the outlet of two water treatment units during two periods
of the year (winter and summer conditions). 相似文献
17.
R. Gupta Y. P. Singh A. K. Rai 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):397-401
Abstract The interaction of the sodium salts of thiosemicarbazones with diphenylantimony chloride in 1:1 molar ratio in benzene solution lead to the formation of derivatives, Ph2Sb[SC(NH2)NN: C(R)R′] where R = H; R′ [dbnd] C6H5, CH3OC6H4, C6H5CH[dbnd]CH, and R′ [dbnd] CH3; R′[dbnd]C6H5, CH3OC6H4, C6H4CH3, respectively. The resulting complexes have been characterised on the basis of elemental analyses and molecular weight determination. The mode of bonding of the ligands with the metal atom has been proposed on the basis of I.R., 1H and 13C NMR studies. All these ligands are found to behave as monofunctional bidentate moiety in these complexes. 相似文献
18.
RuiYan Wu Yong Wang XiaoYan Xue TuoPing Hu JianFeng Gao 《Journal of Dispersion Science and Technology》2019,40(2):186-191
Rare earth elements are an important strategic resource. As one of the most valuable member, lanthanum plays a key role in lanthanide. However, trace Al(III) impurity in lanthanum materials can seriously damage the performance of lanthanum materials. In this paper, a nitrogen-containing activated carbon, AC-PN-700, was synthesized using pine needle as raw material and KOH as activator. The AC-PN-700 was characterized by surface area analyzer, elemental analysis and FT-IR. The adsorption and selective ability of AC-PN-700 towards Al(III) were investigated. The BET specific surface area of AC-PN-700 was 596.4 m2.g?1, and the average pore diameter was 2.7?nm. Depend on its large specific surface, well-developed internal pore structure and abundant nitrogen-containing functional groups, the AC-PN-700 possesses strong adsorption affinity and excellent recognition selectivity towards Al(III). The adsorption capacity of AC-PN-700 towards Al(III) could reach to 3.89?mg.g?1, removal rate towards Al(III) was almost 100%, and relative selectivity coefficients with respect to La(III) is 9.5. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. In addition, AC-PN-700 possesses better regeneration ability and reusability. 相似文献
19.
Imidazole and imine-linked dipodal receptors were decorated on the surface of ZnO nanoparticles. Cation binding assays of these chemosensors showed that receptors 5 and 6 had high selectivity for Al(III) and Zn(II) ions, respectively. The detection limit for Al(III) with receptor 5 was 11 nM, and the detection limit for Zn(II) ion with receptor 6 was 23 nM. 相似文献
20.
《Journal of Coordination Chemistry》2012,65(3-4):253-259
Abstract Reaction of bidentate tertiary phosphines with excess [Co(CNR)5]BF4, or reaction of [Co(CNR)4L-L]BF4 with excess [Co(CNR)5]BF4, leads to bimetallic complexes of the form, [(RNC)4CoL-LCo(CNR)4](BF4)2, R = 2,6-Et2C6H3, L-L = p-Ph2PC6H4PPh2, Ph2PC═CPPh2, Me2PCH2CH2PMe2, Ph2PCH2CH2PPh2, Ph2PCH2CH2CH2PPh2. Comparison of the v(? N═C) IR patterns, electronic spectra, and molar conductivity values of these bimetallic complexes with data for other Co(I)-organoisocyanide complexes indicates that the two -Co(CNR)4 moieties are almost totally independent of each other. Recorded λmax values are the same as for the [Co(CNR)4L-L]BF4 complexes, but the ε values, although very large, are less than double. ΛM values in acetone, and probably also in CH2Cl2, are better interpreted as twice the normal conductivity for 1:1 electrolytes than conductivity for 2:1 electrolytes. 相似文献