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1.
A new series of dioxouranium(VI) complexes of a potential ONNO tetradentate donor 2-aminobenzoylhydrazone of butane-2,3-dione
(L1H2) have been synthesized. At pH 2·5–4·0, the donor (L1H2) reacts in the keto form and complexes of the type [UO2(L1H2)(X)2] (X−=Cl−, Br−, NO
3
−
, NCS−, ClO
4
−
, CH3COO−, 1/2SO
4
2−
) are obtained. At higher pH (6·5–7), the complex of the enol form having the formula [UO2(L1)(H2O)] has been isolated. On reaction with a monodentate lewis base (B), both types of complexes yield adducts of the type [UO2(L1)(B)]. All these complexes have been characterised adequately by elemental analyses and other standard physicochemical techniques.
Location of the bonding sites of the donor molecule around the uranyl ion, status of the uranium-oxygen bond and the probable
structure of the complexes have also been discussed. 相似文献
2.
A. P. Gulya V. I. Tsapkov D. Poirier K. Aruksandei E. Pakhontsu 《Russian Journal of General Chemistry》2010,80(7):1351-1354
2-[(2-Hydroxyphenylimino)methyl]phenol (H2L1) and 1-[(2-hydroxyphenylimino)methyl]naphthalen-2-ol (H2L2) reacted with copper(II) acetate hydrate and sulfanilamide (Sf1), sulfathiazole (Sf2), sulfaethidole (Sf3), sulfadiazine (Sf4), and sulfadimidine (Sf5) in ethanol to give mixed-ligand copper chelates with the composition Cu(Sf1–5)(L1–2) · n H2O (n = 1, 2). All these complexes are monomeric. Salicylaldehyde imines (H2L1 and H2L2) behave as doubly deprotonated tridentate O,N,O ligands, whereas sulfanilamides (Sf1–5) are unidentate ligands. Thermolysis of the synthesized complexes includes dehydration at 70–90°C, followed by complete thermal
decomposition (290–380°C). The complexes [Cu(Sf1)(L1)] · 2H2O and [Cu(Sf3)(L1)] · H2O at a concentration of 10−4 M inhibited growth and reproduction of 100% of human myeloid leukemia cells (HL-60). The inhibitory effect was 90 and 75%,
respectively, at a concentration of 10−5 M, whereas no antitumor activity was observed at a concentration of 10−6 M. 相似文献
3.
Two stable thiazolylazo anion radical complexes of ruthenium(II), [Ru(L1•−)(Cl)(CO)(PPh3)2] (1) and [Ru(L2•−)(Cl)(CO)(PPh3)2] (2) (where L1 = 2′-Thiazolylazo-2-imidazole and L2 = 4-(2′-Thiazolylazo)-1-n-hexadecyloxy-naphthalene), have been synthesized
and characterized by spectroscopic and electrochemical techniques. The radical nature of the complexes has been confirmed
from their room temperature magnetic moments and X-band ESR spectra. The radical complexes display a moderately intense (ε ~ 104 M−1 cm−1) and relatively broad band in 430–460 nm region. In the microcrystalline state, complexes (1) and (2) display strong ESR
signals at g = 1.951 and g = 1.988, respectively. In CH2Cl2 solution, complexes (1) and (2) show a quasireversible one-electron response near −0.64 and −0.59 V, respectively, versus
Ag/AgCl due to the radical redox couple [RuII(L)(Cl)(CO)(PPh3)2]/[RuII (L•−)(Cl)(CO)(PPh3)2]. 相似文献
4.
Dhanpat Rai Mikazu Yui Dean A. Moore Gregg J. Lumetta Kevin M. Rosso Yuanxian Xia Andrew R. Felmy Frances N. Skomurski 《Journal of solution chemistry》2008,37(12):1725-1746
No thermodynamic data for Th complexes with aqueous Si are available. To obtain such data, extensive studies on ThO2(am) solubility were carried out as functions of: (1) a wide range of aqueous silica concentrations (0.0004 to 0.14 mol⋅L−1) at fixed pH values of about 10, 11, 12, and 13; and (2) and variable pH (ranging from 10 to 13.3) at fixed aqueous Si concentrations
of about 0.006 mol⋅L−1 or 0.018 mol⋅L−1. The samples were equilibrated over long periods (ranging up to 487 days), and the data showed that steady-state concentrations
were reached in < 29 days. X-ray diffraction, FTIR, and Raman analyses of the equilibrated solid phases showed that the Th
solids were amorphous ThO2(am) containing some adsorbed Si. The solubility of ThO2(am) at pH values ranging from 10 to 13.3 at fixed 0.018 mol⋅L−1 aqueous Si concentrations decreases rapidly with an increase in pH, and increases dramatically with an increase in Si concentrations
beyond about 0.003 mol⋅L−1 at fixed pH values > 10. The data were interpreted using both the Pitzer and SIT models, and required only the inclusion
of one mixed-hydroxy-silica complex of Th [Th(OH)3(H3SiO4)32−]. Both models provided similar complexation constant values for the formation of this species. Density functional theory
calculations predict complexes of this stoichiometry, having six-fold coordination of the Th cation, to be structurally stable.
Predictions based on the fitted value of log 10
K
0=−18.5±0.7 for the ThO2(am) solubility reaction involving Th(OH)3(H3SiO4)32−[ThO2(am)+3H4SiO4+H2O↔Th(OH)3(H3SiO4)32−+2H+], along with the thermodynamic data for aqueous Si species reported in the literature, agreed closely with the extensive
experimental data and showed that under alkaline conditions aqueous Si makes very strong complexes with Th. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(15):1307-1327
Mononuclear oxorhenium(V) complexes [ReO(HL1 or H2L2)(PPh3)(OH2)Cl]Cl, {H2L1 = 1-(2-hydroxyphenyl)butane-1,3-dione-3-(5,6-diphenyl-1,2,4-triazine-3-ylhydrazone) and H3L2 = 1-(2-hydroxyphenyl)butane-1,3-dione-3-(1H-benzimidazol-2-ylhydrazone)}, have been synthesized by ligand exchange with trans-trichloromonooxo-bis(triphenylphosphine) rhenium(V). The reaction of a 1?:?1 mixture of either NH4SCN, 1,10-phenanthroline (1,10-phen) or 8-hydroxyquinoline (8-OHquin) and H2L1 or H3L2, with trans-ReOCl3(PPh3)2 yielded the mononuclear oxorhenium(V) complexes, [ReO(HL1 or H2L2)(PPh3) (SCN)Cl], [ReO(HL1)(1,10-phen)Cl]Cl, [ReO(H2L2)(1,10-phen)(OH2)]Cl2·H2O and [ReO(HL1 or H2L2) (8-Oquin)Cl]. Thermal studies on these complexes showed structural transformations from mononuclear into binuclear complexes. [Re2O3(HL1 or H2L2)2(PPh3)2Cl2], [Re2O2(μ-L1 or L2)2(SCN)2] and [Re2O3 (H2L2)2(1,10-phen)2]Cl2, were synthesized pyrolytically in the solid state from the respective precursor rhenium complexes. The structures of all complexes and the corresponding thermal products were elucidated using elemental analyses, conductance, IR and electronic absorption spectra, magnetic moments and 1H NMR and TG-DSC measurements. The prepared complexes and their thermal products have octahedral configurations. The ligands H2L1 or H3L2 behave as monoanionic bidentate or monoanionic tetradentate ligands towards the oxorhenium ions. The antifungal activities of the metal complexes towards Alternaria alternata and Aspergillus niger were tested and showed comparable behavior with well known antibiotics. 相似文献
6.
New complexes of type [Cu(L1)2(OH2)]·4H2O (1), [Cu(L2)(OH2)]·0.5H2O (2) and [Cu3(L3)2(OH2)3]·0.5H2O (3) were synthesized by [1 + 1], [1 + 2] and [1 + 3], respectively, template condensation of 2,4,6-triamino-1,3,5-triazine and
salicylic aldehyde in the presence of copper(II). The features of complexes have been established from microanalytical, IR
and UV–Vis data. The thermal analyses have evidenced the thermal intervals of stability and also the accompanying thermodynamic
effects. Processes as water elimination and oxidative degradation of the organic ligands were observed. After water elimination,
complexes revealed a similar thermal behaviour. The final product of decomposition was copper(II) oxide as powder X-ray diffraction
indicated. 相似文献
7.
Enrique Colacio Jose Manuel Dominguez Vera Jose Maria Moreno Jose Ruiz Markku R. Sundberg 《Transition Metal Chemistry》1992,17(5):397-400
Two new imidazolate-bridged dinuclear CuII complexes, Na[Cu2(L1)2(im)] and K[Cu2(L2)2(im)] (where H2L1=6-amino-1,3-dimethyl-5(2-carboxyphenyl)azouracil and H2L2=1,3-dimethyl-5(2-carboxyphenyl)azobarbituric acid) have been prepared and characterized by magnetic susceptibility and spectroscopic
measurements. Both compounds exhibit the expected antiferromagnetic behaviour with 2J=−54.8 and −30.4 cm−1, respectively. Because of the lack of suitable crystals for single crystal X-ray analysis, we have calculated the lowest
energy structures using a program based on the MMX force field. On the basis of the results, the magnitude of the magnetic
interaction is discussed.
TMC 2623 相似文献
8.
Pasquale Crea Concetta De Stefano Mutsa Kambarami Frank J. Millero Virender K. Sharma 《Journal of solution chemistry》2008,37(9):1245-1259
The protonation constants for oxidized glutathione, H
i−1L(4−i+1)−, K
i
H=[H
i
L(4−i)−]/[H
i−1L(4−i+1)−][H+] i=1,2,…,6 have been measured at 5, 25 and 45 °C as a function of the ionic strength (0.1 to 5.4 mol⋅[kg(H2O)]−1) in NaCl solutions. The effect of ionic strength on the measured protonation constants has been used to determine the thermodynamic
values (K
i
H0) and the enthalpy (ΔH
i
) for the dissociation reaction using the SIT model and Pitzer equations. The SIT (ε) and Pitzer parameters (β
(0), β
(1) and C) for the dissociation products (L4−, HL3−, H2L2−, H3L−, H4L, H5L+, H6L2+) have been determined as a function of temperature. These results can be used to examine the effect of ionic strength and
temperature on glutathione in aqueous solutions with NaCl as the major component (body fluids, seawater and brines). 相似文献
9.
Xiaoting Qin Yufei Ji Yanfei Gao Lei Yan Shuai Ding Yanqin Wang Zhiliang Liu 《无机化学与普通化学杂志》2014,640(2):462-468
Three new phenolate oxygen bridged transition metal complexes [Zn3(HL1)3(μ3‐CH3O)]·(ClO4)2(H2O)3 ( 1 ), [Ni2(HL1)2(μ1,1‐N3)(o‐vanillin)]·H2O ( 2 ), [Ni3(HL2)2(PhCOO)2(PhCOOH)2(EtOH)2] ( 3 ) have been synthesized by metal ions and potentially multidentate Schiff base ligands (H2L1 = 2‐((1‐hydroxy‐2‐methylpropan‐2‐ylimino) methyl)‐6‐methoxyphenol; H3L2 = (E)‐1‐((2‐hydroxy‐3‐methoxy‐benzylidene)amino)ethane‐1,2‐diol). All the three complexes 1 , 2 , and 3 have been characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal X‐ray diffraction studies. Crystal structures reveal that complex 1 is a trinuclear incomplete cubane‐like zinc cluster whereas complex 2 is a dinuclear nickel complex bridged by azide, and compound 3 is a trinuclear nickel complex. The luminescent property for complex 1 and magnetic behaviors for complexes 2 and 3 have been investigated. 相似文献
10.
Arpita Banerjee Averi Guha Pali Maiti Somen Goswami Tanmay Chattopadhyay Tapan Kumar Mondal Santanu Bhattacharya Ennio Zangrando Debasis Das 《Transition Metal Chemistry》2011,36(8):829-839
Three Ni(II) complexes of cresol-based Schiff-base ligands, namely [Ni2(L1)(NCS)3(H2O)2], (1) [Ni2(L2)(CH3COO)(NCS)2(H2O)] (2) and [Ni2(L3)(NCS)3] (3), (where L1 = 2,6-bis(N-ethylpyrrolidineiminomethyl)-4-methylphenolato, L2 = 2,6-bis(N-ethylpiperidineiminomethyl)-4-methylphenolato and L3 = 2,6-bis{N-ethyl-N-(3-hydroxypropyl iminomethyl)}-4-methylphenolato), have been synthesized and structurally characterized by X-ray single-crystal diffraction in addition to routine physicochemical techniques. Density functional theory calculations have been performed to understand the nature of the electronic spectra of the complexes. Complexes 1?C3 when reacted with 4-nitrophenyl phosphate in 50:50 acetonitrile?Cwater medium promote the cleavage of the O?CP bond to form p-nitrophenol and smoothly convert 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ) either in MeOH or in MeCN medium. Phosphatase- and catecholase-like activities were monitored by UV?Cvis spectrophotometry and the Michaelis?CMenten equation was applied to rationalize all the kinetic parameters. Upon treatment with urea, complexes 1 and 2 give rise to [Ni2(L1)(NCS)2(NCO)(H2O)2] (1??) and [Ni2(L2)(CH3COO)(NCO)(NCS)(H2O)] (2??) derivatives, respectively, whereas 3 remains unaltered under same reaction conditions. 相似文献
11.
Derivative of 8-hydroxyquinoline i.e. Clioquinol is well known for its antibiotic properties, drug design and coordinating
ability towards metal ion such as Copper(II). The structure of mixed ligand complexes has been investigated using spectral,
elemental and thermal analysis. In vitro anti microbial activity against four bacterial species were performed i.e. Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Bacillus substilis and found that synthesized complexes (15–37 mm) were found to be significant potent compared to standard drugs (clioquinol
i.e. 10–26 mm), parental ligands and metal salts employed for complexation. The kinetic parameters such as order of reaction
(n = 0.96–1.49), and the energy of activation (E
a = 3.065–142.9 kJ mol−1), have been calculated using Freeman–Carroll method. The range found for the pre-exponential factor (A), the activation entropy (S* = −91.03 to−102.6 JK−1 mol−1), the activation enthalpy (H* = 0.380–135.15 kJ mol−1), and the free energy (G* = 33.52–222.4 kJ mol−1) of activation reveals that the complexes are more stable. Order of stability of complexes were found to be [Cu(A4)(CQ)OH] · 4H2O > [Cu(A3)(CQ)OH] · 5H2O > [Cu(A1)(CQ)OH] · H2O > [Cu(A2)(CQ)OH] · 3H2O 相似文献
12.
Biswajit Das Rajesh Chakraborty Sandipan Sarkar Ennio Zangrando Pabitra Chattopadhyay 《Transition Metal Chemistry》2011,36(6):663-667
The solvothermal reaction of [ReOCl3(PPh3)2] with 2,2′-seleno-bis(4,6-di-tert-butylphenol) (H2L1) in ethanol at 95 °C resulted in an oxorhenium(V) complex of formulation [ReO(L1)(L2)] due to the in situ formation of 2-selenochloromethyl-4,6-di-tert-butylphenolate (L2) through the cleavage of one C–Se bond of H2L1. The mononuclear oxorhenium(V) complex was characterized by physicochemical and spectroscopic methods along with detailed
structural analysis by single crystal X-ray crystallography. Electrochemical studies revealed a one-electron equivalent quasi-reversible
voltammogram for the ReO(V)/ReO(VI) redox couple at 1.28 V (versus SCE) with no cathodic response for ReO(V) → ReO(IV) reduction. 相似文献
13.
《Journal of Coordination Chemistry》2012,65(22):4032-4051
Ten new complexes, [Cu2(L1)(NO3)2]·2H2O (1), [Cu4(L1)2]·4ClO4·H2O (2), [Cu2(L1)(H2O)2]·(adipate) (3), [Cu6(L1)2(m-bdc)4]·2DMF·5H2O (4), [Cu2(L1)(Hbtc)]·5H2O (5), [Cu2(L1)(H2O)2]·(ntc)·3H2O (6), [Co2(L2)]·[Co(MeOH)4(H2O)2] (7), [Co3(L2)(EtOH)(H2O)] (8), [Ni6(L2)2(H2O)4]·H2O (9) and [Zn4(L2)(OAc)2]·0.5H2O (10), have been synthesized. 1 displays a [Cu2(L1)(NO3)2] monomolecular structure. 2 shows a supramolecular chain including [Cu2L1]2+. In 3, two Cu(II) ions are connected by L1 to form a [Cu2(L1)(H2O)2]2+ cation. In 4, the m-bdc anions bridge Cu(II) ions and L1 anions to form a layer. Both 5 and 6 display 3-D supramolecular structures. 7 consists of both [Co2L2]2? and [Co(MeOH)4(H2O)2]2+ units. 8 and 9 show infinite chain structures. In 10, Zn(II) dimers are linked by L2 to generate a 3-D framework. The magnetic properties for 4 and 8 and the luminescent property for 10 have been studied. 相似文献
14.
Mousa Al-Noaimi Mohammad El-khateeb Salim F. Haddad Haytham Saadeh 《Transition Metal Chemistry》2010,35(7):877-883
Abstract
Five ruthenium complexes bearing phenylazo-(2-(phenylthio))phenylmethine ligands of the general type trans-[RuII(bpy)(L)(Cl)2] (C1–C5) {L = YC6H4N=NC(COCH3)=NC6H4(2-SC6H5), H (L1), Cl (L2), OCH3 (L3), Br (L4), or NO2 (L5)} have been synthesized. The crystal structure of trans-[Ru(bpy)(L1)(Cl)2] (C1) is reported and shows no direct metal–S interaction. The complexes have been characterized through spectroscopic (IR, UV/vis and NMR) and electrochemical (CV) techniques. The electrochemical parameters (E L(L)) of the azoimine ligands are reported. 相似文献15.
Zala Mahendrasinh Sujit B. Kumar E. Suresh Joan Ribas 《Transition Metal Chemistry》2010,35(6):757-763
A new pyridylpyrazole-containing tetradentate ligand, namely N,N-bis(3,5-dimethylpyrazol-1-ylmethyl)aminomethylpyridine (L), and two of its binuclear azido-bridged complexes, [Ni2(L)2(N3)2](ClO4)2·2EtOH (1) and [Cu2(L)2(N3)2](ClO4)2 (2), have been synthesized and characterized by physico-chemical and spectroscopic methods. The crystal structures of both
complexes are reported. Each metal atom in the complexes has a MN6 coordination environment with distorted octahedral geometry. Variable-temperature magnetic susceptibility measurements for
complex (1) show typical antiferromagnetic behavior with J value −84.5 ± 1.3 cm−1, whereas complex (2) has no magnetic interactions. 相似文献
16.
Brajagopal Samanta Joy Chakraborty Nirmal Kumar Karan R. K. Bhubon Singh Glean P. A. Yap Christoph Marschner Judith Baumgartner Samiran Mitra 《Structural chemistry》2006,17(1):139-147
Two new cyano-bridged trinuclear heterometallic complexes [Sr2(Phen)4(CF3CO2)(H2O)3Fe(CN)6]·2H2O (1) [Ca2(Phen)4(CF3CO2)(H2O)Co(CN)6]·2H2O (2) (where Phen=1,10-phenanthroline) have been synthesized and their crystal structures have been determined. The structure of complex (1) features a central [Fe(CN)6]3− unit that links a monocation, [Sr(Phen)2(OH2)(OOCCF3)]+ and a dication, [Sr(Phen)2(OH2)2]2+ via two trans cyanide bridges. The complex (2) features a central [Co(CN)6]3− unit that links two monocations of [Ca(Phen)2(OH2)(OOCCF3)]+ (the positions of the trifluoro acetate and water molecules are disordered over two positions) via two trans cyanide bridges. Each metal atom is seven coordinated and achieves pentagonal bipyramidal geometry. Two cocrystallized water molecules are present in both the complexes. The presence of an extensive network of hydrogen bonding imparts the overall stability to both the systems. 相似文献
17.
Hana Bashir Shawish Mohammadjavad Paydar Chung Yeng Looi Yi Li Wong Elaheh Movahed Siti Nadiah Abdul Halim Won Fen Wong Mohd-Rais Mustafa Mohd Jamil Maah 《Transition Metal Chemistry》2014,39(1):81-94
Nickel(II) complexes with 2,3-dihydroxybenzaldehyde N4-substituted thiosemicarbazone ligands (H3L1–H3L4) have been synthesized and characterized with the aim of evaluating the effect of N4 substitution in the thiosemicarbazone moiety on their coordination behavior and biological activities. Two series of nickel(II) complexes with the general formulae [Ni(H3L)(H2L)]ClO4 and [Ni2(HL)2] were characterized by analytical and spectral techniques. The molecular structure of one of the complexes, namely, [Ni(H3L4)(H2L4)]ClO4 was established by single crystal X-ray diffraction studies. The crystal structure of this complex revealed that two H3L4 ligands are coordinated to nickel(II) in different modes; one as a neutral tridentate ONS ligand and the other is as a monoanionic tridentate (ONS?) ligand. The antimicrobial activities of the compounds were tested against 25 bacterial strains via the disc diffusion method, and their minimum inhibitory concentration (MIC) and minimum microbicidal concentration were evaluated using microdilution methods. With a few exceptions, most of the compounds exhibited low-to-moderate inhibitory activities against the tested bacterial strains. However, the complexes [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) indicated higher inhibitory activity against Salmonella enterica ATCC 9068 (MIC values 15.7 and <15.7 μg/ml, respectively), compared with gentamicin as the positive control (MIC 25 μg/ml). Complex (7) also inhibited Streptococcus pneumoniae more efficiently (MIC 31.2 μg/ml), compared with gentamicin (MIC > 50 μg/ml). The toxicities of the compounds were tested on brine shrimp (Artemia salina), where no meaningful toxicity level was noted for both the free ligands and the complexes. The cytotoxicities of the compounds on cell viability were determined on MCF7, PC3, A375, and H413 cancer cells in terms of IC50; complexes [Ni(H3L3)(H2L3)]ClO4 (3), [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) exhibited significant cytotoxicity on the tested cell lines. 相似文献
18.
Wen-Kui Dong Jun-Feng Tong Yin-Xia Sun Jian-Chao Wu Jian Yao Shang-Sheng Gong 《Transition Metal Chemistry》2010,35(4):419-426
Two new mono- and dinuclear Cu(II) complexes, namely [CuL1]·0.5H2O (1) and [(Cu2(L2)2)(DMF)]·0.5DMF (2) (H2L1 = 1,2-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)]methylene-aminooxy}ethane; H2L2 = 1,3-bis{[(Z)-(3-methyl-5-oxo-1-phenyl-1H-pyrazolidin-4(4H)-yl)(phenyl)] methyleneaminooxy}propane), have been synthesized and characterized by X-ray crystallography. The unit cell
of complex 1 contains two crystallographically independent but chemically identical [CuL1] molecules and one crystalline water molecule, showing a slightly distorted square-planar coordination geometry and forming
a wave-like pattern running along the a-axis via hydrogen bonding and π···π stacking interactions. Complex 2 has a dinuclear structure, comprising two Cu(II) atoms, two completely deprotonated phenolate bisoxime (L2)2− moieties (in the form of enol), and both coordinated and hemi-crystalline DMF molecules. Complex 2 has square-planar and square-pyramidal geometries around the two copper centers, whose basic coordination planes are almost
perpendicular and form an infinite three-dimensional supramolecular network structure involving intermolecular C–H···N, C–H···O,
and C–H···π(Ph) hydrogen bonding and π···π stacking interactions of neighboring pyrazole rings. 相似文献
19.
The aroylhydrazone Schiff base ligands (E)-N’-(2-hydroxybenzylidene)benzohydrazide = H2L1, (E)-N’-(2-hydroxy-3-methoxybenzylidene)benzohydrazide = H2L2 and = (E)-N’-(5-bromo-2-hydroxybenzylidene)benzohydrazide = H2L3 gave the vanadium(V)oxo-aroylhydrazone complexes [VVOL1(OCH3)(OHCH3] (1), [VVOL2(OCH3)(OHCH3]·CH3OH (2) and [VVOL3(OCH3)(OHCH3] (3) on reaction with vanadium(IV) oxide acetylacetonate. The complexes were characterized by spectroscopic methods in the solid state (IR) and in solution (UV–Vis, 1H NMR). Single crystal X-ray analysis was performed with 3. In methanol solution six-coordinated VVOL3(OCH3)(OHCH3) was formed. VIV was oxidized to Vv by aerial oxygen in the synthesis. In the VO5N coordination sphere the alcohol oxygen lies trans to the oxo oxygen. The general V–O bond length order is oxo < methoxylato < phenoxidic < enolato < alcoholic. The complexes are mononuclear, but intermolecular O–H?N hydrogen bonding affords a zigzag chain. DFT calculations on complex 3 reproduced the geometric parameters, IR and UV–Vis spectroscopic data well in a reasonable range. 相似文献
20.
József Sándor Pap Brigitta Horváth Gábor Speier József Kaizer 《Transition Metal Chemistry》2011,36(6):603-609
Dimanganese complexes Mn2
III(L1)(OAc)4 and Mn2
III(L2)(OAc)4 with the phthalazine-based ligands 1,4-di(2′-benzimidazolyl)aminophthalazine (H2L1) and 1,4-di(N-methyl-2′-benzimidazolyl)aminophthalazine (H2L2) have been prepared and characterized. The complexes accelerate the disproportionation of H2O2 into water and dioxygen in buffered aqueous solutions in a near-neutral pH range thus can be regarded as catalase models.
Results of kinetic measurements indicate a similar mechanism for the two catalysts, but formation of the proposed peroxo-adduct
intermediate is less favored for Mn2
III(L1)(OAc)4. It is presumed to be the reason for the lower rates for this catalyst even at higher pH. 相似文献