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1.
The ortho-metalated complex [Pd(x){κ
2
(C,N)-[C6H4CH2NRR′ (Y)}] (2a–4a and 2b–3b) was prepared by refluxing in benzene equimolecular amounts of Pd(OAc)2 and secondary benzylamine [a, EtNHCH2Ph; b, t-BuNHCH2Ph followed by addition of excess NaCl. The reaction of the complexes [Pd(x){κ
2
(C,N)-[C6H4CH2NRR′ (Y)}] (2a–4a and 2b–3b) with a stoichiometric amount of Ph3P=C(H)COC6H4-4-Z (Z = Br, Ph) (ZBPPY) (1:1 molar ratio), in THF at low temperature, gives the cationic derivatives [Pd(OC(Z-4-C6H4C=CHPPh3){κ
2
(C,N)-[C6H4CH2NRR′(Y)}] (5a–9a, 4b–6b, and 4b′–6b′), in which the ylide ligand is O-coordinated to the Pd(II) center and trans to the ortho-metalated C(6)H(4) group, in an “end-on
carbonyl”. Ortho-metallation, ylide O-coordination, and C-coordination in complexes (5a–9a, 4b–6b, and 4b′–6b′) were characterized by elemental analysis as well as various spectroscopic techniques. 相似文献
2.
Abstract Two new coordination polymers, [CoL(bpp)]
n
(1) and [MnL(bipy)]
n
·0.25nH2L·0.5nH2O (2) (H2L = 1,3-adamantanediacetic acid, bpp = 1,3-bis(4-pyridyl)propane, bipy = 4,4′-bipyridine), were synthesized and characterized
by single crystal X-ray diffraction, IR spectroscopy, and thermal analysis. Complex 1 is an one-dimensional (1D) chain structure of Co(II) bridged by L2− as well as bpp. Complex 2 consists of a two-dimensional (2D) (3,6)-connected topology layer structure. Variable temperature magnetic susceptibility
measurements in the range of 2–300 K reveal the existence of weak antiferromagnetic interactions in two complexes with J = −1.74 cm−1, g = 2.26 for 1 and J = −0.10 cm−1, g = 1.67 for 2.
Index abstract Two mental-organic frameworks, namely [CoL(bpp)]
n
(1) and [MnL(bipy)]
n
·0.25nH2L·0.5nH2O (2) (H2L = 1,3-adamantanediacetic acid, bpp = 1,3-bis(4-pyridyl)propane, bipy = 4,4′-bipyridine), have been synthesized based on
1,3-adamantanediacetic acid and N-donor coligand with metal ions Co(II) and Mn(II). The magnetic measurement of the two polymers
reveals typical antiferromagnetism exchange.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
Melchor González-Dávila J. Magdalena Santana-Casiano Frank J. Millero 《Journal of solution chemistry》2006,35(1):95-111
The oxidation rates of nanomolar levels of Fe(II) in seawater (salinity S = 36.2) by mixtures of O2 and H2O2 has been measured as a function of pH (5.8–8.4) and temperature (3–35∘C). A competition exists for the oxidation of Fe(II)
in the presence of both O2 (μ mol⋅L−1 levels) and H2O2 (nmol⋅L−1 levels). A kinetic model has been applied to explain the experimental results that considers the interactions of Fe(II) with
the major ions in seawater. In the presence of both oxidants, the hydrolyzed Fe(II) species dominate the Fe(II) oxidation
process between pH 6 and 8.5. Over pH range 6.2–7.9, the FeOH+ species are the most active, whereas above pH 7.9, the Fe(OH)02 species are the most active at the levels of CO2−3 concentration present in seawater. The predicted Fe(II) oxidation rate at [Fe(II)]0 = 30nmol⋅L−1 and pH = 8.17 in the oxygen-saturated seawater with [H2O2]0 = 50nmol⋅L−1 (log 10 k = −2.24s−1) is in excellent agreement with the experimental value of log 10 k = −2.29s−1 ([H2O2]0 = 55nmol⋅L−1, pH = 8). 相似文献
4.
Galactose oxidase (GOase) is a fungal enzyme which is unusual among metalloenzymes in appearing to catalyse the two electron
oxidation of primary alcohols to aldehydes and H2O2. The crystal structure of the enzyme reveals that the coordination geometry of mononuclear copper(II) ion is square pyramidal,
with two histidine imidazoles, a tyrosinate, and either H2O (pH 7.0) or acetate (from buffer,pH 4-5) in the equatorial sites and a tyrosinate ligand weakly bound in the axial position. This paper summarizes the results
of our studies on the structure, spectral and redox properties of certain novel models for the active site of the inactive
form of GOase. The monophenolato Cu(II) complexes of the type [Cu(L1)X][H(L1) = 2-(bis(pyrid-2-ylmethyl)aminomethyl)-4-nitrophenol and X− = Cl−
1, NCS−
2, CH3COO−
3, ClO4
−
4] reveal a distorted square pyramidal geometry around Cu(II) with an unusual axial coordination of phenolate moiety. The coordination
geometry of 3 is reminiscent of the active site of GOase with an axial phenolate and equatorial CH3COO− ligands. All the present complexes exhibit several electronic and EPR spectral features which are also similar to the enzyme.
Further, to establish the structural and spectroscopic consequences of the coordination of two tyrosinates in GOase enzyme,
we studied the monomeric copper(II) complexes containing two phenolates and imidazole/pyridine donors as closer structural
models for GOase. N,N-dimethylethylenediamine and N,N’-dimethylethylenediamine have been used as starting materials to obtain
a variety of 2,4-disubstituted phenolate ligands. The X-ray crystal structures of the complexes [Cu(L5)(py)], (8) [H2(L5) = N,N-dimethyl-N’,N’-bis(2-hydroxy-4-nitrobenzyl) ethylenediamine, py = pyridine] and [Cu(L8)(H2O)] (11), [H2(L8) = N,N’-dimethyl-N,N’-bis(2-hydroxy-4-nitrobenzyl)ethylenediamine] reveal distorted square pyramidal geometries around Cu(II) with the axial tertiary
amine nitrogen and water coordination respectively. Interestingly, for the latter complex there are two different molecules
present in the same unit cell containing the methyl groups of the ethylenediamine fragmentcis to each other in one molecule andtrans to each other in the other. The ligand field and EPR spectra of the model complexes reveal square-based geometries even in
solution. The electrochemical and chemical means of generating novel radical species of the model complexes, analogous to
the active form of the enzyme is presently under investigation. 相似文献
5.
V. F. Shul’gin E. A. Sarnit O. V. Konnik E. B. Rusanov A. S. Bogomyakov V. I. Ovcharenko V. V. Minin 《Russian Journal of Coordination Chemistry》2012,38(1):44-49
The structures and results of the static magnetic susceptibility investigation of the copper(II) binuclear complex with salicylic
acid diacyl hydrazide (H2L), [Cu2(L)(Py)4] (I), and the copper(II) trinuclear complex with diacyl dihydrazide of salicylic and glutaric acids (H6L′), [Cu3(L′)(Py)4] · 2Py (II), are described. The exchange antiferromagnetic interactions between the paramagnetic centers with the exchange interaction
parameter −2J = 119 cm−1 for dimer I and 14 cm−1 for trinuclear complex II are detected. 相似文献
6.
M. M. Degtyarik A. S. Lyakhov O. A. Ivashkevich Yu. V. Grigoriev 《Russian Journal of Coordination Chemistry》2012,38(2):77-85
The reactions of Co(II), Ni(II), and Cu(II) chlorides and bromides and their metallic powders with tetrazol-1-yl-tris(hydroxymethyl)methane
(L) afforded new complexes ML2Hal2 · mH2O(M = Co(II) or Ni(II), Hal = Cl−; M = Cu(II), Hal = Cl− or Br−, m = 0; and M = Co(II) or Ni(II), Hal = Br−, m = 2), MLnCl2 (M = Co(II) or Ni(II), n = 2 or 4; M = Cu(II), n = 2), and MLnBr2 · mH2O (M = Ni(II), n = 2, m = 2; M = Cu(II), n = 2, m = 0). The compositions and structures of the synthesized complexes were determined by elemental analysis, IR spectroscopy
(50–4000 cm−1), and X-ray diffraction analysis. The introduction of a bulky substituent into position 1 of the tetrazole cycle was shown
to exert almost no effect on the coordination mode but affected the composition and structure of the complexes. 相似文献
7.
In the compound [Ni(Bptc)2(Bimb)2(H2O)2] (I), where H4Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two
Bimb ligands, two O atoms from two H2Bptc2− ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction. 相似文献
8.
Francisco Ramón Fortea-Pérez Giovanni De Munno 《Journal of Coordination Chemistry》2014,67(23-24):4003-4015
New bis(oxamato)palladate(II) complexes, [Pd(H2O)4][Pd(2,6-Me2pma)2]·2H2O (1), (n-Bu4N)2[Pd(2,6-Me2pma)2]·2H2O (2a), and (n-Bu4N)2[Pd(2,6-Me2pma)2]·2CHCl3 (2b) (2,6-Me2pma = N-2,6-dimethylphenyoxamate and n-Bu4N+ = tetra-n-butylammonium), have been synthesized and the structures of 1 and 2b characterized by single-crystal X-ray diffraction. Complex 1 is a double salt constituted by tetraaquapalladium(II) cations and bis(oxamato)palladate(II) anions interlinked by hydrogen bonds. The palladium(II) ions in 1 are four-coordinate with two oxygens and two nitrogens from two fully deprotonated oxamate ligands (anion), and four water molecules (cation) building centrosymmetric square-planar surroundings. Centrosymmetric bis(oxamato)palladate(II) anions occur in 2b as in 1, the charge balance in this compound being ensured by the bulky n-Bu4N+. The catalytic role of 1 and 2a for the Suzuki reaction has been investigated by using a series of aryl iodide/bromide derivatives in the conventional organic medium dimethylformamide. The tetraaquapalladium(II) unit in 1 appears to be active in the catalytic Suzuki cross-coupling reactions, but it readily decomposes to inactive palladium black. 相似文献
9.
Electrocatalytic oxygen reduction was studied on a RuxFeySez(CO)n cluster catalyst with Vulcan carbon powder dispersed into a Nafion film coated on a glassy carbon electrode. The synthesis
of the electrocatalyst as a mixture of crystallites and amorphous nanoparticles was carried out by refluxing the transition
metal carbonyl compounds in an organic solvent. Electrocatalysis by the cluster compound is discussed, based on the results
of rotating disc electrode measurements in a 0.5 M H2SO4. A Tafel slope of −80.00±4.72 mV dec−1 and an exchange current density of 1.1±0.17×10−6 mA cm−2 was calculated from the mass transfer-corrected curve. It was found that the electrochemical reduction reaction follows the
kinetics of a multielectronic (n=4e−) charge transfer process producing water, i.e. O2+4H++4e−→2H2O.
Electronic Publication 相似文献
10.
S. I. Orysyk L. N. Rybachuk V. I. Pekhnyo V. V. Orysyk 《Russian Journal of Inorganic Chemistry》2011,56(11):1747-1751
New Pd(II) complexes with 1-allyl-3-(2-pyridyl)thiourea (APTU) of the formulas [Pd(C9H11N3S)Cl2] (I) and [Pd(C9H11N3S)2]Cl2 (II) were obtained and examined by UV-Vis, IR, and 1H NMR spectroscopy. The conditions for the complexation reactions were optimized.
The instability constants and molar absorption coefficients of these complexes were calculated. Comparison of the characteristic
bands in the UV-Vis and IR spectra of the complexes and free APTU revealed that the ligand in both complexes is coordinated
to the metal atom in the thione form in the bidentate chelating mode through the S atom of the thiourea group and the pyridine
N atom. In the UV-Vis spectra of the complexes, the charge transfer bands (π → π* Py) and n → π* (C=NPy), (C=S) experience hypsochromic shifts by 450–470 cm−1 caused by the coordination of APTU to the metal ion, which gives rise to ligand-metal charge-transfer bands (C=NPy → Pd, n → π* (C=S)) and (SPd). The protons in the 6-, 4-, and 3-positions of the pyridine ring and the thiourea NH proton in the
chelate ring are most sensitive to the complexation. 相似文献
11.
Two two-dimensional coordination complexes, {[Cu4(BTM)6(OPA)4] · 4DMF · 3H2O}
n
(1) and {[Cu(BDTM)(OH)](ClO4) · 2H2O}
n
(2) (BTM = bis(1,2,4-triazol-1-yl)methane, BDTM = bis(3,5-dimethyl-1,2,4-triazol-1-yl)methane, OPA2− = ortho-phthalic dianion, DMF = N,N-dimethylformamide), were synthesized and structurally characterized. Each Cu(II) ion locates in a distorted square pyramidal
geometry in 1, in which OPA2− ligands bridge Cu2+ ions along a axis to form a magnetic transmission chain and BTM ligands act as flexible spacers to construct the two-dimensional layer
structure. In 2, each Cu2+ ion adopts tetra-coordination geometry to two hydroxyl groups and two triazolyl nitrogen atoms from two different BDTM ligands.
Two hydroxyl groups bridge two Cu2+ ions to form a rhombic diamond, and four BDTM ligands connect four diamonds to form a 36-membered macrocyclic structure with
large channels along a axis. Magnetic properties revealed that both OPA2− and OH− mediate anti-ferromagnetic interactions between Cu2+ ions with J = − 0.06(3) and −301.9(2) cm−1 for 1 and 2, respectively.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
T. E. Kokina L. A. Sheludyakova A. V. Tkachev E. G. Boguslavskii A. M. Agafontsev N. B. Gorshkov S. V. Larionov 《Russian Journal of General Chemistry》2011,81(8):1651-1657
Coordination compounds Cu2(H2L1)Cl4 (I), Pd2(H2L1)Cl4 (II), Cu2(H2L2)Cl4 (III), and Pd2(H2L2) Cl4 (IV) with chiral bis-α-sulfanyloximes, the derivatives of the monoterpenoid (−)-α-pinene, were obtained. The complexes I and III are paramagnetic (μeff = 2.45 and 2.67 μB, respectively), II and IV are diamagnetic. According to IR spectroscopy, in the compounds I–IV the nearest environment of Cu and Pd atoms includes
N, S, and Cl atoms. The values of μeff and parameters of ESR spectra of the solid phase and solutions of I and III show a binuclear structure of the Cu(II) complexes. Parameters of the 1H and 13C NMR spectra of compounds II and IV indicate the formation of binuclear Pd(II) complexes of C
2 symmetry and the closure of fivemembered chelate rings PdNSC2. The PdCl2 fragments are in transoid position. H2L1 and H2L2 are tetradentate bridging chelating ligands. 相似文献
13.
The kinetics of ethylene oxidation by PdCl2 and CrO3 complexes supported on silica gel (300 K, closed batch reactor) and the adsorption of C2H4 by silica gel and metal complex reaction centers (M
n
) were studied. A new version of the kinetic distribution method was applied to determine the rate constants of ethylene reactions with metal complexes with consideration for the equilibrium distribution of C2H4 among the reactor gas phase, silica gel, and M
n
. The rate constant of a first-order reaction with respect to Cr(VI) (k
e) remained constant as [M
n
] was increased up to 0.15 mol % with the absence of detectable ethylene adsorption by chromium(VI). In the case of Pd(II)/SiO2, strong ethylene adsorption by palladium(II) was found, and k
e was an exponential function of [M
n
]. This exponential function is indicative of an increase in the specific activity of Pd(II) with palladium concentration on SiO2. Taking into account the adsorption of ethylene (physisorption on SiO2 and chemisorption on Pd(II)), we found an analogy between the kinetic behaviors of Pd(II) in reactions with ethylene on silica gel and with ethylene and other hydrocarbons in solutions. 相似文献
14.
Dong-Yu Lv Zhu-Qing Gao Jin-Zhong Gu Jian-Zhao Liu Wei Dou 《Transition Metal Chemistry》2011,36(3):275-281
Two Mn(II) coordination polymers, namely [Mn(bpda)]
n
(1) and [Mn(bpda)(bpy)0.5]
n
(2) (H2bpda = 1,1′-biphenyl-3,3′-dicarboxylic acid and bpy = 4,4′-bipyridine), have been synthesized from H2bpdc, bpy, and MnSO4·2H2O under hydrothermal conditions. The complexes were characterized by physicochemical and spectroscopic methods, as well as
by X-ray crystallography. Compound 1 possesses a 3D structure consisting of carboxylate-bridged edge-sharing Mn–O–Mn double chains. Compound 2 features a 3D open structure with a dinuclear Mn(II) secondary building unit. Magnetic susceptibility measurements of compounds
1 and 2 exhibit antiferromagnetic interactions between the nearest Mn(II), with J = –11.3 cm−1 and g = 2.12 for 1, and J = –13.5 cm−1 and g = 2.12 for 2. 相似文献
15.
Model Pb(II) thiocomplexes with mono- and bidentate ligands of the composition [Pb(L1,2) n ]2−n (L1 is (SC6H5)− (thiophenolate ion), L2 is (S2CN(CH3)2)− (dithiocarbamate ion), n is the number of ligands of 2–6), which simulate fragments of the crystal structures of Pb(II) complex compounds with organic ligands, are studied within density functional theory. Geometric and energy parameters of model complexes with different coordination geometries of the Pb atom are determined and the stereochemical activity of the lone electron pair (LEP, E) of the Pb2+ ion is estimated in them. In the studied complexes, the highest Pb-S binding energy is found for the Pb atom surrounded by 2–4 ligands. The geometry of the Pb atom coordinated by S donor atoms can be described in terms of the valence shell electron pair repulsion (VSEPR) model with stereochemically active LEP. The coordination number (cn) of the Pb atom in the most energetically favorable complexes [Pb(SC6H5) n ]2−n is (3+E) − (4+E), and in [Pb(S2CN(CH3)2) n ]2−n complexes, it is (4+E) and (6+E). Configurations with the mentioned cns are most often observed in the crystal structures of Pb(II) thiocomplex compounds. 相似文献
16.
I. A. Efimenko N. A. Dobrynina O. N. Shishilov N. A. Ivanova O. S. Erofeeva 《Russian Journal of Coordination Chemistry》2012,38(4):233-239
Complexation in the systems Pd(II)-Cl−-HA-H2Glu (HA is the l- or d-conformer of 2-methylamino-1-phenylpropanol; H2Glu is glutamic acid) was studied using pH-metric titration, electronic absorption spectroscopy, and quantum-chemical modeling.
It was found that the ratio of the complex species largely depends on pH and the amine, the crucial factor being stabilization
of the structures by hydrogen bonding. This provides explanation to the previous data on the different radioprotective activities
of the complexes (H2A)2[PdCl4] containing the l- and d-conformers of the ligand HA. 相似文献
17.
Aqueous solution of water soluble colloidal MnO2 was prepared by Perez-Benito method. Kinetics of l-methionine oxidation by colloidal MnO2 in perchloric acid (0.93 × 10−4 to 3.72 × 10−4 mol dm−3) has been studied spectrophotometrically. The reaction follows first-order kinetics with respect to [H+]. The first-order kinetics with respect to l-methionine at low concentration shifts to zero order at higher concentration. The effects of [Mn(II)] and [F−] on the reaction rate were also determined. Manganese (II) has sigmoidal effect on the rate reaction and act as auto catalyst.
The exact dependence on [Mn(II)] cannot be explained due to its oxidation by colloidal MnO2. Methionine sulfoxide was formed as the oxidation product of l-methionine. Ammonia and carbon dioxide have not been identified as the reaction products. The mechanism with the observed
kinetics has been proposed and discussed. 相似文献
18.
Bojidarka B. Koleva Tsonko Kolev Marc Lamshöft Michael Spiteller 《Transition Metal Chemistry》2008,33(7):911-919
The coordination behaviour of the tripeptide glycyl-l-phenylalanyl-glycine (H-Gly-Phe-Gly-OH) with Au(III), Pd(II), and Pt(II) in both solution and in the solid state has been
investigated experimentally. In addition, quantum chemical calculations have been carried out with a view to obtain the structures
and spectroscopic properties of the ligand and its complexes. Both in solution and in the solid state the tripeptide interacts
in a tetradentate manner with the Au(III) and Pd(II) ions through the NH2, two deprotonated amide N atoms and the COO−group, forming [Au(H-Gly-Phe-Gly-OH)H−2)] × H2O and [Pd(H-Gly-l-Phe-Gly-OH)H−2)]Na × H2O complexes. The MN3O chromophores are calculated to be near planar. Interaction with cisplatin leads to the formation of a mononuclear complex
with tridentate coordination of the ligand by NH2 and two N- atoms from the deprotonated amide groups ([Pt(H-Gly-l-Phe-Gly-OH)H−2)NH3] × 2H2O). The fourth coordination position of the Pt(II) is occupied by an NH3 ligand. The PtN4 chromophore is flat with a deviation from planarity of 0.3°.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
19.
R. L. Fernandes P. M. Takahashi R. C. G. Frem A. V. G. Netto A. E. Mauro J. R. Matos 《Journal of Thermal Analysis and Calorimetry》2009,97(1):123-126
The synthesis and thermal behavior of the new [Pd(fum)(bipy)]
n
·2nH2O (1), [Pd(fum)(bpe)]
n
·nH2O (2) and [Pd(fum)(pz)]
n
·3nH2O (3) {bipy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethene and pz = pyrazine} fumarate complexes are described in this work
as well their characterization by IR and 13C CPMAS NMR spectroscopies. TG curves showed that the compounds released organic ligands and lattice water molecules in the
temperature range of 46–491 °C. In all the cases, metallic palladium was identified as the final residue. 相似文献
20.
A. P. Gulya D. Gynzhu N. N. Bairak D. Poirier V. I. Tsapkov 《Russian Journal of General Chemistry》2009,79(7):1499-1503
2-Formylpyridine semicarbazone L reacts with cobalt, nickel, copper and zinc chlorides, nitrates and perchlorites to form
coordination compounds of compositions ML2X2·nH2O (M=Co, Ni, Cu, Zn; X = Cl, NO3, ClO4; L = NC5H4-CH=N-NH-C(O)-NH2; n = 0, 1) and CuLX2·nH2O (X = Cl, Br, NO3; n = 0−0.5). Complex CuL(NO3)2 has polynuclear, CuLX2·0.5H2O (X = Cl, Br), binuclear, and other compounds, mononuclear structures. Azomethine L behaves in them as tridental N,N,O-ligand. Thermolysis of these complexes proceeds through such stages as dehydration (80–95°C),
deactivation (145–155°C) and complete theral degradation (170–590°C). Complexes CuLX2·nH2O (X = Cl, NO3; n = 0−0.5) were established to inhibit in vitro the growth and reproduction of 100% of cancer cells of human mieloid leukaemia
HL-60 at 10−4 M concentration. At 10−5 M concentration they inhibit only 10% of cells, and at 10−6 M concentration they do not possess anticancer activity. 相似文献