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1.
A. A. Pasynskii S. S. Shapovalov A. V. Gordienko I. V. Skabitskii 《Russian Journal of Coordination Chemistry》2011,37(2):127-132
Reactions of cymantrenecarboxylic acid (CO)3MnC5H4COOH (CymCOOH) with Ni(II) and Co(II) pivalates in boiling THF followed by extraction of the products with diethyl ether or benzene and treatment with triphenylphosphine gave the binuclear complexes LM(CymCOO)4ML (M = Ni (I) and Co (II); L = PPh3). Treatment of the benzene extract of the intermediate cobalt cymantrenecarboxylate with 2,6-lutidine (L’) yielded the trinuclear complex L’Co(CymCOO)3Co(CymCOO)3CoL’ (III). Complex I is antiferromagnetic; μeff decreases from 3.7 to 0.9 μB in a temperature range from 300 to 2 K. Structures I-III were identified using X-ray diffraction. The frameworks of complexes I and II are like Chinese lanterns, having four carboxylate bridges and axial ligands L (Ni-P, 2.358(1) Å; Co-P, 2.412(2) Å). The metal atoms are not bonded to each other (Ni…Ni, 2.7583(9) Å; Co…Co, 2808 (2) Å). In complex III, either terminal Co atom is coordinated to one ligand L’ (Co-N, 2.059(2) Å). The Co atoms form a linear chain showing no M-M bonds (Co…Co, 3.346(1) Å), in which either terminal Co atom is linked with the central Co atom by three carboxylate bridges (on average, Cocentr-O, 2.164 Å; COterm-O, 2.094 Å). In one of three carboxylate groups, only one carboxylate O atom serves as a bridge, while the other is bonded to the terminal Co atom only (Coterm-O, 2.094 and 2.389 Å); so this carboxylate group is a bridging and chelating ligand. 相似文献
2.
Summary Complexes of the type M(AcLeu)2 · B2 (M = CoII, NiII or ZnII; B = H2O, py, 3-pic, 4-pic; AcLeu =N-acetyl-DL-leucinate ion) and M(AcLeu)2 B (M = CoII or ZnII and B = o-phen) were prepared and investigated by means of magnetic and spectroscopic measurements. The i.r. spectra of all the complexes are consistent with bidentate coordination of the amino acid to the metal ion. The room temperature solid state electronic spectra indicate that the symmetry of this species is closer toD
4h
and that MO6 and MO4N2 chromophores are present in the M(AcLeu)2 · 2 H2O and M(AcLeu)2Bn · x H2O (B = py, 3-pic, 4-pic, n=2 and x=0 for M = NiII; B = o-phen, n=1 and x=0 for M = CoII; B = py, 3-pic, 4-pic, n=1 and x=1 for M = CoII) complexes, respectively. By comparing the Dq values of the amino acid and those of other N-substituted amino acids previously studied, a spectrochemical series of the the cobalt(II) and nickel(II) complexes is proposed. The1 H n.m.r. spectra of the zinc(II) complexes confirm the proposed stereochemistry. 相似文献
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Summary Cobalt(II), nickel(II) and copper(II) complexes of 2-thiouracil and its arylazo derivatives were prepared. The elemental analysis suggest a range of 11, 21 and 13 stoichiometries. Electronic spectra and magnetic susceptibility measurements were used to infer the structures and the i.r. spectra of the ligands and their complexes to identify the type of bonding. 相似文献
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6.
Zh. V. Dobrokhotova I. G. Fomina M. A. Kiskin A. A. Sidorov V. M. Novotortsev I. L. Eremenko 《Russian Chemical Bulletin》2006,55(2):256-266
Solid-phase thermal decomposition of polynuclear NiII and CoII pivalate complexes was studied by differential scanning calorimetry and thermogravimetry. The decomposition of the polynuclear
(from bi-to hexanuclear) CoII carboxylate complexes is accompanied by aggregation to form a volatile octanuclear complex. Thermolysis of the polynuclear
NiII carboxylates results in their destructure, and the phase composition of the decomposition products is determined by the
nature of coordinated ligands.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 250—260, February, 2006. 相似文献
7.
The temperature-jump method has been used to determine the nickel(II)- and cobalt(II)-arginine complexation kinetics. In the pH range studied, the neutral form of the ligand, HL, is the attacking, as well as the complexed, ligand species. The reactions reported on are of the type where n = 1, 2, 3 and M is Ni or Co. At 25° and ionic strength 0.1M the association rate constants are: for nickel(II) k1 = 2.3 × 103(±20%), k2 = 2.4 × 104(±20%), k3 = 3.5 × 104(±40%) M?1 sec?1; for cobalt(II) k1 = 1.5 × 105(±20%), k2 = 8.7 × 105(±20%), k3 = 2.0 × 105(±40%) M?1 sec?1. Arginine binds to metal ions less well than homologous chelating agents due to the electrostatic repulsion arising from the positively charged terminus of the zwitterion. Kinetically, the effect appears in the association rate constants with nickel reactions more strongly influenced than cobalt. 相似文献
8.
Summary Binuclear NiII and CoII complexes derived from 2,6-diformyl-4-methylphenol and various aromatic monoamines have been prepared and investigated. The NiII complexes have Ni2LCl3 composition while the CoII complexes have Co2L2Cl2 composition, where L represents the organic ligand. The complexes are active catalysts in the oxidation of 3,5-di-t-butylcatechol (3,5-DTBC) by dioxygen, but less so than their Cu analogues. This result is attributed to the absence of antiferromagnetic coupling between the metal centres. 相似文献
9.
A. V. Vologzhanina E. N. Zorina-Tikhonova A. K. Matyukhina A. A. Sidorov P. V. Dorovatovskii I. L. Eremenko 《Russian Journal of Coordination Chemistry》2017,43(12):801-806
The reactions of single crystals containing 36-nuclear anionic complexes of cobalt(II), (NBu4)8[Co36(H2O-κO)12(μ3-OH)20(μ4-Me2Mal-κ2O,O′)24(μ4-Me2Mal)6] · 2.5H2O ? CH3OH (I), and nickel(II), (NBu4)8[Ni36(H2O-κO)12(μ3-OH)20(μ4-Me2Mal-κ2O,O′)24(μ4-Me2Mal)6] · 6H2O ? 2C2H5OH (II) and (NHEt3)3[Ni36(NHEt3)(H2O-κO)12.25(μ3-OH)20(μ4-HMe2Mal-κ2O,O′)4(μ4-Me2Mal-κ2O,O′)20(μ4-Me2Mal)6] · 39H2O (III), with solutions of 1,4-dioxane and a 0.1 M solution of Dabco (Dabco is 1,4-diazabicyclo[2.2.2]octane) in EtOH are studied. An ethanol solution of Dabco dissolves the crystals of the complexes, whereas the insertion of the solvent molecules with single crystal retention (for the cobalt compound containing tetrabutylammonium cation, I), cracking (for the nickel analog, II), or dissolution (for the cobalt complex containing triethylammonium, III) occurs in 1,4-dioxane. The X-ray diffraction analyses show the substitution of the uncoordinated water and ethanol molecules in the starting compound by 1,4-dioxane molecules in the structure of compound I to form (NBu4)8[Co36(H2O-κO)12(μ3-OH)20(μ4-Me2Mal-κ2O,O′)24(μ4-Me2Mal)6] · 7C4H8O2 (IV), which is accompanied by a change in the conformation and the shift of tetrabutylammonium cations, indicating a possibility of the modification of the 36-nuclear d-metal complexes with the malonic acid derivatives in the solid-phase resolvation reactions (CIF files CCDC no. 1557499 (III) and 1557500 (IV)). 相似文献
10.
The kinetics and mechanism of the removal of M2+ from bis-(heptane-2,4,6-trionato)M(II) [M = Ni, Co] by ethylenediminetetraacetic acid (EDTA), nitrilotriacetic acid (NAT), 1,2-cyclohexanediamine-N, N, N′, N′-tetraacetic acid (CyDTA), and ethylenebis(oxyethylenenitrilo)tetraacetic acid (EGTA) have been investigated using stopped-flow spectrophotometry in methanol-water at 25°C and ionic strength 0.1 mol dm?3 KNO3. The reactions were investigated at a number of different pHs. An associative mechanism is proposed to account for the kinetic data. Although all the ligands have similar functional groups, their reactivity towards the parent complex is quite different. The pH dependence of the rate constants has been used to determine the relative reactivities of the various ligand species present. In the case of nitrilotriacetic acid, a nonlinear dependence on ligand concentration is observed, thus confirming the mechanism proposed. © 1995 John Wiley & Sons, Inc. 相似文献
11.
Summary [MCl2L4] complexes (M = Co or Ni; L = 3-hydroxypyridine) were prepared by the reaction of stoichiometric amounts of 3-hydroxypyridine and MCl2 in EtOH solution. The complexes were chlorinated by passing Cl2 gas through EtOH solutions containing the metal(II) chloride and 3-hydroxypyridine to yield [CoCl2(LCl)2]·2H2O and [NiCl2(LCl)4]·4H2O, respectively. Structural assignments have been inferred from elemental and spectral analyses. Magnetic properties of the complexes are assigned and the electronic transitions are discussed. 相似文献
12.
Potentiometric sensors for determining cobalt and nickel ions are described. They are based on the use of cobalt and nickel tris(1,10-phenanthroline)-TPB as electroactive compounds dispersed in plasticized poly(vinyl chloride) matrix. The sensors exhibit fast, near-Nernstian responses for cobalt and nickel-phenanthroline cations over the pH range 3–11 with a slope of 30.3 ± 0.3 mV/concentration decade. In the presence of excess 1,10-phenanthroline reagent, cobalt(II) and nickel(II) ions at concentration levels as low as 4 × 10–6
M are accurately determined. The results show an average metal ion recovery of 98.5% with a mean standard deviation of 0.5%. Cobalt in organometallic compounds and nickel in silicate rocks are determined by these sensors and results agreeing fairly well with atomic absorption spectrometry are obtained. 相似文献
13.
Mohsen M. Mostafa Abd El-Hammid M. Shallaby Ahmed A. El-Asmy 《Transition Metal Chemistry》1981,6(5):303-305
Summary The preparation and characterization of CuII, CoII, NiII and HgII complexes containing 1,4-diphenylthiosemicarbazide (DPhTSC) of the type [Cu(DPhTSC-H)X.H2O]nH2O (X= Cl, Br or Ac; n=0 or 1) · [M(DPhTSC-H)2yH2O] (M=CoII or NiII; y=0 or 1) and [Hg(DPhTSC)Cl2]2 H2O and [Cu(D-PhTSC)2SO4]H2O are reported. The stereochemistry of the complexes have been studied with the help of magnetic and electronic measurements. The anomalous magnetic moments observed in all cases have been explained. The i.r. spectral studies have been used to determine the bonding sites in the complexes. 相似文献
14.
J. Sanmartín M. R. Bermejo J. A. García-Vázquez J. Romero A. Sousa J. Strähle A. Brodbeck 《Transition Metal Chemistry》1993,18(2):187-190
Summary The electrochemical oxidation of anodic metal (nickel or cobalt) in MeCN solutions of 1-hydroxy-2-pyridinethione (HPT) gives [Ni(PT)2], [Co(PT)2] or [Co(PT)3]. When 1,10-phenanthroline (phen) or 2,2-bipyridine (bipy) are added to the electrolytic phase the product is a complex, [Ni(PT)2L] or [Co(PT)2L] (L = bipy or phen). The i.r., u.v. and 1H- and 13C-n.m.r. spectra of the complexes are discussed.This paper was presented at the 5th Inorganic Chemistry Meeting of the Royal Spanish Chemical Society, Tossa de Mar, Girona, Spain, September 1991. 相似文献
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V. I. Kornev M. G. Semenova D. A. Merkulov 《Russian Journal of Coordination Chemistry》2010,36(8):591-596
Equilibria in binary and ternary systems containing cobalt(II) and nickel(II) salts, iminodiacetic acid, and dicarboxylates
were studied by spectrophotometry at I = 0.1 (NaClO4) and T = 20 ± 2°C. The molar and proton compositions of the resulting complexes and the pH ranges of their existence were determined.
The stability constants of the homo- and heteroleptic complexes were calculated. The pH-distribution of the detected complexes
was obtained. The experimental data were analyzed using the mathematical models that predict the existence of a wide spectrum
of complex species in solution and allow ignoring those species that are negligible for accurate reproduction of the observed
pattern. 相似文献
17.
Acetylsalicylhydroxamic acid (AcSHA) was prepared and characterized. Its pKa value was determined as 7.78. Solid metal complexes of AcSHA were also prepared and characterized by elemental analysis, electronic and i.r. spectroscopies, and by magnetic moment measurements. The shift of both hydroxamic and acetyl carbonyl vibrations to lower frequencies clearly indicates that AcSHA is bonded through oxygen atoms to the metal ions as a tridentate ligand. On the basis of the experimental data, structures for the complexes are purposed. 相似文献
18.
Structural studies of diamine complexes of cobalt(II) and nickel(II) thiocyanates and selenocyanates
Summary Complexes of the types ML2X2 [M = cobalt(II) or nickel(II); L = hydrazine, ethylenediamine (en) or o-phenylenediamine (opd) and X = SCN– or SeCN–] and NiL2(NCS)2MCl2 [M = cadmium(II) or mercury(II)] have been prepared and characterised by elemental analysis, molar conductance, molecular weight determination, magnetic susceptibility, electronic and i.r. spectral measurements. 相似文献
19.
The tris(2,2′-bipyridine)cobalt(II) complex gives a reversible d.c. wave with E = ?1.02 V vs. SCE and a sharp differential pulse peak at Ep = ?1.03 V in a salted-out acetonitrile phase. A simple selective method is described for the determination of cobalt(II); down to 0.25 μg of cobalt(II) can be determined in presence of large amounts of Ni, Zn, Cd, Pb, and Cu; iron(III) can be masked with sodium fluoride. The method is applicable to the determination of >0.0l% cobalt in nickel salts and >5 × 10?5% cobalt in iron salts. Nickel(II) can also be extracted from aqueous solution and determined by differential pulse polarography, even in presence of a 20-fold amount of cobalt(II) by masking with EDTA; >0.01% of nickel in cobalt salts can be determined reproducibly. 相似文献
20.
Cyclic voltammetry and controlled potential coulometry studies of 2,2′-bipyridyl, 4,4′-dimethyl-2,2′-bipyridyl and 2,2′, 2″-terpyridyl complexes of Fe(II), Co(II) and Ni(II) in acetonitrile are described. E1/2 values for M(III)/M(II) and M(II)/M)I) couples are compared and crystal field effects discussed. A series of M(I) and M(III) polypyridyl complexes have been prepared by controlled potential electrolysis; these include a number of 3+ and 1+ oxidation state complexes of nickel which have not previously been isolated — [Ni(bipy)3]-(ClO4)3, [Ni(dimbipy)3](ClO4)3, [Ni(terpy)2](ClO4)3 and [Ni(bipy)2]ClO4. 相似文献