共查询到20条相似文献,搜索用时 0 毫秒
1.
Alfonso Castiñeiras María Consuelo F. Vidal Rosa Carballo 《Transition Metal Chemistry》1995,20(5):477-480
Summary The coordination behaviour of N,N-bis(1-carboxymethyl)dithioxamide (GLYDTO), N,N-bis(1-carboxyethyl)dithioxamide (ALADTO), N,N-bis(1-carboxy-2-methylpropyl) dithioxamide (VALDTO) and N,N-bis(1-carboxy-3-methylbutyl)dithioxamide (LEUDTO) has been investigated by isolating and characterizing the dinuclear, neutral cobalt(II) complexes, [Co2(L-4H)(H2O)2] (L = GLYDTO, ALADTO, VALDTO or LEUDTO) and [Co2(L-4H)(H2O)6] (L = ALADTO or VALDTO). All ligands were characterized by mass, i.r., and 1H- and 13C-n.m.r. spectroscopy. The complexes possess distorted octahedral structures as revealed by the magnetic and electronic (diffuse reflectance) spectral data. The i.r. data indicate that the ligands are bis-tridentate, bis-dianions coordinated to each metal ion through the carboxylate oxygen, deprotonated thioamide nitrogen and thiocarbonyl sulphur atoms. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(23):4144-4162
Reactions of anhydrous CoX2 (X?=?Br?, SCN?) and Ni(ClO4)2 with N,N,N′,N′-tetraisobutylpyridine-2,6-dithiocarboxamides (S-dbpt), N,N,N′,N′-tetraisopropyl pyridine-2,6-dithiocarboxamides (S-dppt), and N,N,N′,N′-tetraethylpyridine-2,6-dithiocarboxamides (S-dept) lead to the formation of [Co(S-dbpt)Br2] (1), [Co(S-dppt)(SCN)2] (2), and [Ni(S-dept)2]·(ClO4)2·H2O (3), respectively. The X-ray crystal structures of the three S-dapt ligands and three complexes along with spectroscopic analyzes are presented. The molecular structure investigations of the S-dapt ligands show that the thiamide planes are twisted with respect to the pyridine ring, which is more in the case of phenyl groups. The structures of the Co(II) complexes reveal that an increase in steric crowding on the amide side arms of the ligands has no substantial effect on the geometry adopted by the corresponding complexes. The Co(II) gives only 1?:?1 five-coordinate, ion-paired complexes with a distorted square pyramidal geometry. Ni(II), on the other hand, prefers an octahedral geometry with 1?:?2 metal–ligand ratio. The coordination behavior of S-dapt has been compared to the analogous oxo(O-daap) ligands. Lesser propensity of S atom to get involved in H-bonding interactions ensures an S-N-S type of tridentate coordination by S-dapt. 相似文献
3.
Danuta Czakis-Sulikowska Joanna Radwańska-Doczekalska Bożena Kuźnik Anna Malinowska 《Transition Metal Chemistry》1995,20(2):203-207
Summary Complexes of empirical formulae [ML2Cl2(OH2)2], [CoL2Br2(OH2)2]L·4H2O, [NiL2Br2(OH2)2]L2·2H2O, [ML2(OH2)4]L2(NO3)2 and [ML4(OH2)2](ClO4)2·2H2O (M = CoII, NiII, L = 2,4-bipyridyl) were synthesized and characterized by elemental and spectral analyses. The thermal decomposition of the complexes was also investigated.Author to whom all correspondence should be directed. 相似文献
4.
《Journal of Coordination Chemistry》2012,65(16):2890-2898
The complexes cis-bis(N-furoyl-N′,N′-diethylthioureato-k 2O,S)nickel(II) and cis-bis(N-furoyl-N′,N′-diethylthioureato-k 2O,S)copper(II) were prepared by the reaction of metal acetate with the corresponding acylthiourea derivative. The complexes were characterized by IR, 1H-NMR, 13C-NMR, and single-crystal X-ray diffraction. Both complexes show two furoylthiourea ligands bonded to metal to form a four-coordinate complex with square-planar geometry. The antifungal activity of the prepared complexes was studied against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides, responsible for important plant diseases. 相似文献
5.
Summary MnII, NiII and CuII complexes of (1,3-bis-aminomethyl)-cyclohexane-N,N,N,N-tetrakisbenzimidazole (CDTB) have been prepared and characterized by spectral techniques. The complexes are monomeric and pseudo-octa-hedral, as evidenced by their e.p.r. spectra and analytical data. Parameters
2,
2,
2 and for CuII complexes, and the crystal field splitting parameter (10 Dq) together with the Nephelauxetic ratio (), for NiII complexes, are reported. 相似文献
6.
《Journal of Coordination Chemistry》2012,65(2):256-271
Reactions of M(NO3)2?·?xH2O [M?=?Co(II), Ni(II), and Cu(II)] with N,N,N′,N′-tetraalkylpyridine-2,6-dicarboxamides(O-daap) in CH3CN yield [Co(O-dmap)(NO3)2] (1), [Co(O-deap)(NO3)2] (2), [Co(O-dpap)(NO3)2] (3), [Ni(O-dmap)(H2O)3](NO3)2] (4), [Ni(O-deap)(H2O)2(NO3)](NO3)] (5), [Cu(O-deap)(NO3)2] (6), and [Cu(O-dpap)(NO3)2] (7). X-ray crystal structures of 1, 2, 4, 5, and 7 reveal that O-daap ligands coordinate tridentate to each metal, O–N–O, with nitrate playing a vital role in molecular and crystal structures of all the complexes. The coordination geometry in the two Co(II) complexes, 1 and 2, is approximately pentagonal bipyramidal with nitrate bonded in a slightly unsymmetrical bidentate chelating mode. [Ni(dmap)(H2O)3](NO3)2 (4) and [Ni(deap)(H2O)2(NO3)](NO3) (5) exhibit octahedral geometry, the former containing uncoordinated nitrate while the latter has one nitrate coordinated unidentate and the other nitrate outside the coordination sphere. The Cu(II) in [Cu(dpap)(NO3)2] (7) occupies a distorted square pyramidal geometry and is linked to two unidentate nitrates, although one nitrate is also involved in a weak interaction with the metal through its other oxygen. IR spectra and other physical studies are consistent with their crystal structural data. O-dmap?=?N,N,N′,N′-tetramethylpyridine-2,6-dicarboxamides; O-deap?=?N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamides; and O-dpap?=?N,N,N′,N′-tetraisopropylpyridine-2,6-dicarboxamides. 相似文献
7.
Mononuclear Co(II), Zn(II) and Cd(II) complexes derived from bidentate or tridentate N,N′,N-bis((1H-pyrazol-1-yl)methyl)amines (Ln = LA, LB), where LA is N,N-bis((1H-pyrazol-1-yl)methyl)-3-methoxypropan-1-amine and LB is 3-methoxy-N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)propan-1-amine, have been synthesized and characterized. The geometry at Co(II) and Cd(II) for [LACoCl2], [LBCoCl2] and [LBCdBr2] with N,N′,N-tridentate ligands (Ln = LA, LB) can be described as a distorted trigonal bipyramid achieved by coordinative interaction of Npyrazole, two halides and the nitrogen of amine moiety. However, the molecular structure of four-coordinate [LAZnCl2] can be best described as tetrahedral, resulting in an eight-membered chelate ring. [LACoCl2] polymerized methyl methacrylate in the presence of modified methylaluminoxane at 60 °C and resulted in poly(methylmethacrylate) (PMMA) with higher molecular weight and narrower polydispersity index compared to the other synthesized complexes. However, all the synthesized complexes yielded syndiospecific PMMA, characterized using 1H NMR spectroscopy, with ca. 0.70. 相似文献
8.
Kapoor Pratibha Kumar Ajay Nistandra Jyotsna Venugopalan Paloth 《Transition Metal Chemistry》2000,25(4):465-469
The title compound N,N,N′,N′-tetraethylpyridine-2,6-dicarboxamide (DEAP) forms a 1:1 complex with anhydrous CuCl2, [Cu(DEAP)Cl2], (1) which was crystallized from EtOH solution in the monoclinic space group P21/ n with cell constant, a = 10.024(1); b = 13.122(1); c = 14.404(1) Å β = 101.31(1)° V = 1857.8(3) Å3 and Z = 4. The chloro-perchlorato complex, [Cu(DEAP)Cl(ClO4)], (2) obtained in near quantitative yield by reacting (1) with an excess of NaClO4 in EtOH, crystallized in the monoclinic space group P21/ n with cell constants, a = 7.965(1); b = 25.827(2); c = 10.046(1) Å β = 98.81(1)° V = 2042.2(4) Å3 and Z = 4. Both (1) and (2) contain 5-coordinated copper linked to DEAP through O~N~O donor set of atoms with covalently bonded chlorine atoms in (1) and chlorine and perchlorate groups in (2). The coordination geometry is intermediate between square pyramidal and trigonal bipyramidal, and is probably best described as a trigonally distorted rectangular pyramid. 相似文献
9.
We have studied the spectral (IR, PMR, EAS) and thermal properties of new ZnX2 complexes (X = Cl, Br, I) with N,N-dimethyl-NN,NN-dimethylthiocarbamoyl sulfenamide (L). We have established that the {[ZnLX2]}2 compounds obtained are dimers with Zn—X bridging bonds and monodentate coordination of L through the thione sulfur atom. 相似文献
10.
Manuel A.V. Ribeiro da Silva Bernd Schröder Vasco B.M. Castro Luís M.N.B.F. Santos 《The Journal of chemical thermodynamics》2008,40(4):599-606
Two substituted N-acylthioureas and the respective Ni(II) and Cu(II) complexes were synthesized, namely: N,N-di-n-butyl-N′-thenoylthiourea (Hnbtu); N,N-di-iso-butyl-N′-thenoylthiourea (Hibtu); bis[N,N-di-n-butyl-N′-thenoylthioureato]nickel(II), [Ni(nbtu)2]; bis[N,N-di-n-butyl-N′-thenoylthioureato]copper(II), [Cu(nbtu)2]; bis[N,N-di-iso-butyl-N′-thenoylthioureato]nickel(II), [Ni(ibtu)2]; bis[N,N-di-iso-butyl-N′-thenoylthioureato]copper(II), [Cu(ibtu)2]. The standard (p° = 0.1 MPa) molar enthalpies of formation and sublimation of the two N-acylthioureas were measured, at T = 298.15 K, by rotating-bomb combustion calorimetry and Calvet microcalorimetry, respectively. The standard (p° = 0.1 MPa) molar enthalpies of formation of the Ni(II) and Cu(II) complexes were determined, at T = 298.15 K, by high precision solution–reaction calorimetry. From the results obtained, the enthalpies of hypothetical metal–ligand and metal–metal exchange reactions, in the gaseous phase, were derived, thus allowing a discussion of the gaseous phase energetic difference between the complexation of Ni(II) and Cu(II) to 1,3-ligand systems with (S,O) ligator atoms. 相似文献
11.
12.
S. N. Gridchin 《Journal of Analytical Chemistry》2007,62(6):522-525
Stability constants of Zn2+, Cd2+, and Co2+ complexes of trimethylenediamine-N,N,N′,N′-tetraacetic acid were determined at 298.15 K and ionic strengths of 0.1, 0.5, and 1.0 by potentiometric titration. Potassium nitrate and chloride were used as supporting electrolytes. The results obtained were extrapolated to the zeroth ionic strength using an equation with one individual parameter, and the thermodynamic stability constants of the complexes were calculated. The results are compared with the corresponding data on related compounds. 相似文献
13.
《Journal of Inorganic and Nuclear Chemistry》1981,43(12):3275-3276
The acid dissociation constants of N,N′-bis(2-hydroxyethyl) aminomethyl phosphonic acid (BHAMP) and the stability constants with Zn++ and Mn++ were determined at 25°C and at an ionic strength of 0.10 by means of potentiometric methods. The existence of a stable chelate species YM is illustrated. The equilibrium constants reported were calculated by the method developped by Schwartzenbach. 相似文献
14.
V. Yu. Gusev A. V. Radushev D. A. Muksinova V. N. Vaulina 《Russian Journal of Inorganic Chemistry》2012,57(5):738-743
Extraction of Cu(II), Co(II), Ni(II), and Zn(II) with N-(para-tert-butylbenzoyl)-N??,N??-dialkylhydrazines was studied. In contrast to other listed elements, copper(II) is extracted with these reagents in a wide pH range and NH3 concentrations, which provides its selective separation. Effect of chain length of the N??,N??-alkyl groups and solvent nature on copper extraction and its stripping conditions were determined. Extraction constants were calculated. Ammonium salts decrease the extraction degree of copper(II). The studied reagents are superior to the known industrial reagent of ??-diketone class, LIX 54, in terms of copper(II) extraction efficiency from ammonia media. 相似文献
15.
The thermal decomposition behaviour of polymeric complexes of Cu(II) and Hg(II) with N,N-bis(dithiocarboxy)piperazine is investigated in air by thermogravimetric (TG), derivative thermogravimetric (DTG) and differential thermal analysis (DTA) techniques. The kinetic parameters (non-isothermal method) for their decomposition have been evaluated by graphical as well as by least-squares methods. The equations of Coats-Redfern, Freeman-Carroll and Horowitz-Metzger have been applied. The results indicate that the values ofE,A and S obtained by these three different methods agree well. It was also found that the decomposition of these metal chelates follow first-order kinetics.
The authors are thankful to Prof. C. G. R. Nair, Head of the Department of Chemistry, University of Kerala and Dr. M. P. Kannan, Department of Chemistry, University of Calicut for some helpful discussions. 相似文献
Zusammenfassung Mittels TG, DTG und DTA wurde das thermische Zersetzungsverhalten von Polymerkomplexen aus Cu(II) bzw. Hg(II) mit N,N-Bis(dithiocarboxy)piperazin an Luft untersucht. Für ihre Zersetzung (nichtisotherme Methode) wurden die kinetischen Parameter sowohl graphisch als auch durch Methoden mit den kleinsten Fehlerquadraten ermittelt. Dabei wurden die Gleichungen von Coats-Redfern, Freeman-Carroll und von Horowitz-Metzger angewendet. Alle drei Verfahren zeigen übereinstimmende Resultate fürE, A undS. Es wurde weiterhin gefunden, daß diese Metallchelate einer Reaktion erster Ordnung unterliegen.
The authors are thankful to Prof. C. G. R. Nair, Head of the Department of Chemistry, University of Kerala and Dr. M. P. Kannan, Department of Chemistry, University of Calicut for some helpful discussions. 相似文献
16.
Ahmed A. Abdel-Khalek Mohamed M. Khalil Eman S. H. Khaled 《Transition Metal Chemistry》1993,18(2):153-157
The kinetics of the oxidation of [N-(2-hydroxyethyl)-ethylene-diamine-N,N,N-triacetato] cobalt(II), [CoII-(HEDTA)]–, by N-bromosuccinimide, NBS, have been studied in aqueous solutions and water-methanol solvent mixtures under various conditions. The reaction stoichiometry indicates that one mole of NBS reacts with one mole of [CoII(HEDTA)]–. In aqueous solutions the reaction obeys the following rate law:
相似文献
17.
《Polyhedron》2001,20(15-16):1885-1890
The macrocycle L, prepared by template condensation of bis-6,6′′-(α-methylhidrazino)-4′-phenyl-2,2′:6′′,2′-terpyridine with glyoxal, forms a stable crystalline complex of cobalt(II) [Co(L)(H2O)2][PF6]2 which has been used as a starting material to prepare, for electrochemical studies, a series of seven coordinate cobalt(II) complexes [Co(L)X2][PF6]2 (X=pyridine, 4-cianopyridine, 4-aminopyridine, 4-dimethylaminopyridine, pirazine, imidazole, 1-methylimidazole, 2-methylimidazole, and trimethylphosphite). Cyclic voltammetry of the aquo complex in DMSO show one reversible reduction wave at −1.35 V versus Ag ∣ AgBF4 reference electrode and controlled potential electrolysis in the presence of trimethylphosphite affords a diamagnetic species which has been assigned as a mononuclear d8 Co(I) species. The crystal and molecular structure of [Co(L)(imidazole)2][PF6]2·Me2CO shows the metal to be in a pentagonal-bipyramidal N7 environment. 相似文献
18.
《Journal of Inorganic and Nuclear Chemistry》1976,28(3):443-445
The complexes of N,N′-didodecildithiooxamide (L): CoL3(ClO4)3, NiL2X2 (X = Cl, Br, I, ClO4, HSO4), CuL2X2 (X = ClO4, HSO4) and CuLX2 (X = Cl, Br) were prepared. The cobalt and nickel complexes are diamagnetic, with octahedral and planar coordination respectively. The copper complexes are paramagnetic with normal magnetic moments corresponding to a tetragonal coordination. The i.r. and far i.r. spectra are discussed. 相似文献
19.
Tanja V. Soldatović Enisa Selimović Biljana Šmit Darko Ašanin Nevena S. Planojević Snežana D. Marković 《Journal of Coordination Chemistry》2019,72(4):690-706
The mechanism of substitution from tetrahedral [ZnCl2(en)] and square-pyramidal [ZnCl2(terpy)] complexes (where en = 1,2-diaminoethane or ethylenediamine and terpy = 2,2′:6′,2′′-terpyridine) by guanosine-5′-monophosphate (5′-GMP) have been investigated by 1H NMR spectroscopy. The substitution reaction of [ZnCl2(terpy)] complex is faster than the reaction of [ZnCl2(en)], which was finished after 48?h. Information about the structures of the final products in solution were obtained from the DFT calculations (B3LYP/6-31G(d)) and experimental 1H NMR data acquired during the course of the reaction. The cytotoxic activity of zinc(II) complexes was tested on human breast cancer cell line MDA-MB-231, human colon cancer cell line HCT-116 and normal human lung fibroblast cell line MRC-5. Both complexes reduced cell viabilities, while [ZnCl2(terpy)] was significantly cytotoxic on MDA-MB-231 after 72?h, and HCT-116 after 24?h without dose dependence. The differences in reactivity toward 5′-GMP and cytotoxic activity of Zn(II) complexes may be attributed to the very stable square-pyramidal geometry of [ZnCl2(terpy)] in solution, while weak ligand effect of the en compared to the terpy affected slow interaction of tetrahedral [ZnCl2(en)] complex with the target bio-molecule. 相似文献
20.
A new 1,2-diamine ligand, N,N-bis(2-hydroxyethyl)stilbenediamine (L), has been prepared by reduction of the condensation product of benzaldehyde with 2-aminoethanol with Al amalgam. Mononuclear complexes of the [CuL(H2O)]X2 type where X=Cl– or AcO– with CuII and PdLCl2 with palladium(II) have been prepared and characterized by elemental analysis and i.r., u.v.–vis. or 1H-n.m.r. spectroscopy. 相似文献
|