共查询到20条相似文献,搜索用时 31 毫秒
1.
S. I. Levchenkov L. D. Popov I. N. Shcherbakov V. G. Vlasenko A. A. Tsaturyan S. S. Beloborodov A. M. Ionov V. A. Kogan 《Russian Journal of General Chemistry》2014,84(10):1970-1978
Binuclear complexes of copper(II) with 1′-phthalazinylhydrazones of substituted salicylic aldehydes have been prepared and studied. Antiferromagnetic exchange interaction between copper(II) ions has been revealed in all the complexes. Taking advantage of quantum-chemical simulation, we have investigated the influence of the complexes structural isomerism on the character of the exchange interaction between the paramagnetic centers. X-ray absorbance spectroscopy afforded the structural parameters of coordination spheres of copper(II) ions; it has been demonstrated that dimerization occurred via the nitrogen atoms of phthalazine fragments. 相似文献
2.
L. D. Popov S. I. Levchenkov I. N. Shcherbakov V. A. Kogan Yu. P. Tupolova 《Russian Journal of General Chemistry》2010,80(3):493-500
1′-Phthalazine hydrazone of diacetyl monooxime and its Cu(II) and Ni(II) complexes were synthesized. The acid-base properties
of the hydrazone were potentiometrically and spectrophotometrically studied, and quantum-chemical calculations of the ionization
constants and the energies of possible tautomeric forms and conformations were performed. Complexes of copper(II) prepared
by the reaction of the hydrazone with copper(II) acetate, chloride, and bromide were shown to have the dimeric structure with
the bidentatebridging N-O-groups of the oxime fragment, whereas the copper(II) complex prepared from copper(II) nitrate, forms
the dimer via the endocyclic nitrogen atoms of the phthalazine fragment. 相似文献
3.
《European Polymer Journal》1986,22(12):973-977
Complexes of picolinic acid with the chlorides and bromides of manganese(II), iron(II), cobalt(II), nickel(II) and copper(II) have been prepared. Spectral and magnetic studies have shown that the iron complexes have discrete octahedral structures while the other complexes have polymeric octahedral structures. The decomposition of the complexes was studied by thermogravimetry and differential thermal analysis. The performance of the complexes as colouring materials for poly(vinyl chloride) has also been investigated. 相似文献
4.
Douglas X. West Cinda S. Carlson Authrine C. Whyte Anthony E. Liberta 《Transition Metal Chemistry》1990,15(1):43-47
Summary Spectral and thermal information, as well as activity againstAspergillus niger, have been obtained for 2-acetylpyridine4
N-ethylthiosemicarbazone and its iron(III), cobalt(II,III), nickel(II) and copper(II) complexes. 相似文献
5.
Srinivasa Budagumpi Naveen V. Kulkarni M. P. Sathisha Sandeep P. Netalkar Vidyanand K. Revankar D. K. Suresh 《Monatshefte für Chemie / Chemical Monthly》2011,35(6):487-494
Abstract
An oligoquinoxaline derivative with phthalazine core has been prepared by condensation of 1,4-dihydrazinophthalazine with 2,3-dichloroquinoxaline in dry ethanol followed by acid hydrolysis. Classical endogenous bridging of phthalazine core with its diazine fragment was established in the transition metal(II) complexes derived from the ligand system by using various physicochemical and spectral techniques. The organic host acts as a hexadentate chelate with N4O2 donating sites for coordination towards later first-row transition metal ions. Complexes are in good agreement with the octahedral geometry and found to be 1:1 electrolytes. All synthesized compounds were screened for anticonvulsant activity in Wistar rats by using maximal electroshock method. The ligand, and Co(II) and Ni(II) complexes show appreciable suppression towards electroshock-induced seizures. 相似文献6.
I. Mohamed Mustafa M.A. Hapipah Mahmood Ameen Abdulla T. Robinson Ward 《Polyhedron》2009,28(18):3993-3998
Ni(II), Cu(II), and Zn(II) complexes with bidentate Schiff bases derived from the condensation reaction of 5-chlorosalicylaldehyde, 5-nitrosalicylaldehyde, and 3,5 ditertiarybutyl-2-hydroxy benzaldehyde with tryptamine, have been reported. The ligands and complexes were characterized by elemental analysis, IR, 1H NMR and UV–Vis spectroscopy as well as single crystal X-ray structure analysis whenever possible. The complexes were found to have the general formula [M(L)2]. Spectral studies reveal that these Schiff bases were acting as bidentate ligands and co-ordinating to the metal center through deprotonated phenolate oxygen and azomethine nitrogen atoms. The Zn(II) complexes establish a tetrahedral geometry in a 1:2 metal to ligand stoichiometry, whereas a square planar geometry was proposed for the nickel and copper complexes, slightly distorted in the case of the latter.The antiulcer activity of 5-chlorosalicylaldehyde derivative and its nickel and copper complexes were evaluated in ethanol-induced gastric mucosal injury in rats. This Schiff base and its complexes promote ulcer protection as ascertained by the comparative decrease in ulcer areas, and inhibition of edema and leucocyte infiltration of the submucosal layer. 相似文献
7.
Reactions of copper(II)-phenol systems with O2: models for TPQ biosynthesis in copper amine oxidases
Tabuchi K Ertem MZ Sugimoto H Kunishita A Tano T Fujieda N Cramer CJ Itoh S 《Inorganic chemistry》2011,50(5):1633-1647
Copper(II) complexes supported by a series of phenol-containing bis(pyridin-2-ylmethyl)amine N(3) ligands (denoted as L(o)H, L(m)H, and L(p)H) have been synthesized, and their O(2) reactivity has been examined in detail to gain mechanistic insights into the biosynthesis of the TPQ cofactor (2,4,5-trihydroxyphenylalaninequinone, TOPA quinone) in copper-containing amine oxidases. The copper(II) complex of L(o)H (ortho-phenol derivative) involves a direct phenolate to copper(II) coordination and exhibits almost no reactivity toward O(2) at 60 °C in CH(3)OH. On the other hand, the copper(II) complex of L(m)H (meta-phenol derivative), which does not involve direct coordinative interaction between the phenol moiety and the copper(II) ion, reacts with O(2) in the presence of triethylamine as a base to give a methoxy-substituted para-quinone derivative under the same conditions. The product structure has been established by detailed nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and electrospray ionization-mass spectroscopy (ESI-MS) (including (18)O-labeling experiment) analyses. Density functional theory predicts that the reaction involves (i) intramolecular electron transfer from the deprotonated phenol (phenolate) to copper(II) to generate a copper(I)-phenoxyl radical; (ii) the addition of O(2) to this intermediate, resulting in an end-on copper(II) superoxide; (iii) electrophilic substitution of the phenolic radical to give a copper(II)-alkylperoxo intermediate; (iv) O-O bond cleavage concomitant with a proton migration, giving a para-quinone derivative; and (v) Michael addition of methoxide from copper(II) to the para-quinone ring and subsequent O(2) oxidation. This reaction sequence is similar to that proposed for the biosynthetic pathway leading to the TPQ cofactor in the enzymatic system. The generated para-quinone derivative can act as a turnover catalyst for aerobic oxidation of benzylamine to N-benzylidene benzylamine. Another type of copper(II)-phenol complex with an L(p)H ligand (para-phenol derivative) also reacts with O(2) under the same experimental conditions. However, the product of this reaction is a keto-alcohol derivative, the structure of which is qualitatively different from that of the cofactor. These results unambiguously demonstrate that the steric relationship between the phenol moiety and the supported copper(II) ion is decisive in the conversion of active-site tyrosine residues to the TPQ cofactor. 相似文献
8.
M.S. Sujamol C.J. Athira Y. Sindhu K. Mohanan 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(1):106-112
Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a novel heterocyclic azo derivative, formed by coupling diazotized 2-amino-3-carbethoxy-4,5-dimethylthiophene with acetylacetone were synthesized and characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV–vis, IR, 1H NMR and EPR spectral data. Spectral studies revealed that the ligand existed in an internally hydrogen bonded azo-enol form rather than the keto-hydrazone form and coordinated to the metal ion in a tridentate fashion. Analytical data revealed that all the complexes exhibited 1:1 metal–ligand ratio. On the basis of electronic spectral data and magnetic susceptibility measurements, suitable geometry was proposed for each complex. The nickel(II) complex has undergone facile transesterification reaction when refluxed in methanol for a long period. The ligand and the copper(II) complex were subjected to X-ray diffraction study. The electrochemical behaviour of copper(II) complex was investigated by cyclic voltammetry. The thermal behaviour of the same complex was also examined by thermogravimetry. 相似文献
9.
M. S. Sujamol Y. Sindhu C. J. Athira K. Mohanan 《Russian Journal of Inorganic Chemistry》2011,56(8):1276-1283
An azo derivative was synthesized by coupling diazotized 2-amino-3-carbethoxy-4,5-dimethylthiophene with 2-naphthol and this
new ligand formed a series of metal complexes with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) salts. These complexes were characterized
on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV-Visible, IR and 1H NMR spectral data. Analytical data revealed that all the complexes exhibited 1: 1 metal-ligand ratio. Spectral studies showed
that the ligand existed in an internally hydrogen bonded azo-enol form rather than the keto-hydrazone form and coordinated
to the metal ion in a tridentate fashion. On the basis of electronic spectral data and magnetic susceptibility measurements,
suitable geometry was proposed for each complex. The ligand and its cobalt(II) complex were subjected to X-ray diffraction
study. The thermal behaviour of the ligand and its copper(II) complex was examined by thermogravimetry. The ligand and its
copper(II) and nickel(II) complexes were applied to silk fabric and their fastness properties were evaluated. 相似文献
10.
B. R. Carson G. Kenessey J. R. Allan G. Liptay 《Journal of Thermal Analysis and Calorimetry》1995,44(3):739-743
The chloro complexes of 2-amino-3-methylpyridine with cobalt(II) and copper(II) have been prepared in ethanolic solution and
solid compounds have been isolated. The compounds have stoichiometry ML2Cl2 whereM is Co2+ or Cu2+ and L is 2-amino-3-methylpyridine. Spectral and magnetic studies have been used to obtain information about the environment
of the metal ion in these compounds. The compounds have tetrahedral structures. The thermal decomposition of each compound
has been studied using thermogravimetry and differential thermal analysis. Thermogravimetry studies show that the cobalt complex
forms an intermediate compound before the metal oxide is produced while the copper compound undergoes decomposition with loss
of organic ligand and the formation of copper chloride which then decomposes to give an oxide of copper.
The enthalpy of reaction for each of the processes has been calculated from the thermal analysis curves. 相似文献
11.
Copper(II) and zinc(II) complexes supported by a popular beta-diketiminate ligand (1(-), 2-mesitylamino-4-mesitylimino-2-pentene), [CuII(1)(AcO)] and [[ZnII(1)]2(mu-MeO)(mu-AcO)], have been demonstrated to undergo an oxidative degradation to give a ketone diimine derivative (2) under aerobic conditions. The crystal structures of the mononuclear copper(II) and dinuclear zinc(II) complexes of the beta-diketiminate ligand as well as the copper(II) complex of the modified ligand have been determined by X-ray crystallographic analysis. Mechanism for the oxidative degradation reaction of the beta-diketiminate ligand is also discussed. 相似文献
12.
Mohan N. Patel Bhupesh S. Bhatt Promise A. Dosi 《Journal of Thermal Analysis and Calorimetry》2012,107(1):55-64
The square-pyramidal copper(II) complexes with ciprofloxacin in the presence of bipyridine derivatives have been synthesized
and characterized using elemental analysis, magnetic moment measurement, thermal analysis (TG), IR, mass and reflectance spectra.
The thermal denaturation study has been used for evaluating calf thymus DNA interaction activity. Spectral and hydrodynamic
measurements have been used for validating the DNA interaction study. The thermodynamic profile was established for proper
understanding of DNA binding Gibbs free energy. 相似文献
13.
For a new sulfoethylated chitosan derivative with the degree of substitution of amino group hydrogen atoms of 0.5, the dissociation constant of functional groups has been determined by potentiometric titration. Complexing properties of sulfoethylated chitosan toward copper(II), cobalt(II), nickel(II), zinc(II), manganese(II), cadmium(II), silver(I), lead(II), magnesium(II), calcium(II), strontium(II), and barium(II) ions have been studied potentiometrically. Alkaline earth and magnesium ions do not form complexes with sulfoethylated chitosan. For the other ions, stability constants of the resulting complexes have been determined. The most stable N-2-sulfoethyl chitosan complexes are those with copper(II) and silver(I) ions. 相似文献
14.
Vaneet K. Sharma Sonam Bansal Ashok K. Malik † Rakesh K. Mahajan 《International journal of environmental analytical chemistry》2013,93(14-15):1105-1110
A procedure has been developed for the direct fourth derivative spectrophotometric determination of zinc(II) dimethyldithiocarbamate by converting it into its copper(II) dimethyldithiocarbamate complex, which is then dissolved in Triton X-100. Beer's law is obeyed over the concentration range 0.5–30?µg/mL in the final solution. Various parameters such as the effect of pH and the interference of a number of ions on the determination of Ziram have been studied in detail. The method is sensitive and can be used for the determination of Ziram in commercial samples like Zirax and Ziron containing Ziram and from wheat grains. 相似文献
15.
Kazuma Gotoh Hiroyuki Ishida 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(11):o473-o478
The structures of three isomeric compounds, C7H4ClNO4·C8H6N2, of phthalazine with chloro‐ and nitro‐substituted benzoic acid, namely, 3‐chloro‐2‐nitrobenzoic acid–phthalazine (1/1), (I), 4‐chloro‐2‐nitrobenzoic acid–phthalazine (1/1), (II), and 4‐chloro‐3‐nitrobenzoic acid–phthalazine (1/1), (III), have been determined at 190 K. In the asymmetric unit of each compound, there are two crystallographically independent chloronitrobenzoic acid–phthalazine units, in each of which the two components are held together by a short hydrogen bond between an N atom of the base and a carboxyl O atom. In one hydrogen‐bonded unit of (I) and in two units of (II), a weak C—H...O interaction is also observed between the two components. The N...O distances are 2.5715 (15) and 2.5397 (17) Å for (I), 2.5655 (13) and 2.6081 (13) Å for (II), and 2.613 (2) and 2.589 (2) Å for (III). In both hydrogen‐bonded units of (I) and (II), the H atoms are each disordered over two positions with (N site):(O site) occupancies of 0.35 (3):0.65 (3) and 0.31 (3):0.69 (3) for (I), and 0.32 (3):0.68 (3) and 0.30 (3):0.70 (3) for (II). The H atoms in the hydrogen‐bonded units of (III) are located at the O‐atom sites. 相似文献
16.
S. V. Zvezdina N. V. Chizhova N. Zh. Mamardashvili 《Russian Journal of General Chemistry》2014,84(10):1989-1993
Metal exchange reaction of (octaphenyltetraazaporphyrinato)magnesium(II) with copper, cobalt, and zinc chlorides in dimethyl sulfoxide and dimethylformamide has been studied by spectrophotometry. Kinetic and thermodynamic parameters of the process have been determined, and a probable reaction mechanism has been proposed. Zinc(II), copper(II), cobalt(II), and cobalt(III) complexes of octaphenyltetraazaporphyrin have been isolated and characterized. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(14):2179-2185
The synthesis and X-ray crystal structures of three discrete copper(II) complexes of 1,4-bis(di-2-pyridylmethyl)phthalazine (L) are reported. The complexes 1–3 have Cu2L, Cu3L and Cu2L2 composition and display interesting relationships to previously reported complexes of this ligand. 相似文献
18.
Thirty-six new ferroin compounds have been investigated as possible chelation regents for the calorimetric detection and determination of trace amounts of iron(II), copper(I), and cobalt(II). Spectral data, solution conditions favourable for chelate formation, and other data are reported. The results reveal that incorporation of triazoline heterocycles in ferroin chromophore groupings generally leads to poor chromogenic properties, except with respect to cobalt. Triazine groups, however, can give rise to superior properties. The most sensitive iron(II) chromogen of the ferroin type found to date and a promising new cobalt chromogen are described. 相似文献
19.
G. A. Gamov M. N. Zavalishin A. Yu. Khokhlova A. V. Gashnikova V. A. Sharnin 《Russian Journal of General Chemistry》2018,88(7):1436-1440
Composition of coordination compounds formed by copper(II) or zinc(II) ions and pyridine-2-, -3-, and -4-carbohydrazones of pyridoxal-5-phosphate in aqueous solution at 298.2 K, рН 7.4, I 0.25 has been studied by means of spectrophotometry. Conditional constants of the complexes stability have been determined. Cu(II) ions formed more stable ML2 coordination compounds in comparison with Zn(II), zinc(II) ions are efficiently bound to the derivative of picolinic acid hydrazide to form the ML complex. 相似文献
20.
The synthesis and analytical properties of dimedone bisguanylhydrazone (DIBG) are described for the first time. DIBG is oxidized by aerial oxygen and the reaction is catalysed by copper(II). The catalytic effect of copper(II) is increased by the presence of pyridine. Kinetic methods are described for determining trace amounts of copper(II) and pyridine. The reaction is followed spectrophotometrically by measuring the rate of change of absorbance at 550 nm. The calibration graphs are linear in the range 0.6-9.5 mug for copper(II) and 0.2-8.8 mg for pyridine. The methods have been applied to the determination of copper in galena and of pyridine in piperidine and isoamyl alcohol. The kinetic parameters of the reaction have been determined. 相似文献