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1.
Five oxovanadium(IV) dinuclear complexes described by the overall formula [(VO)2(IA)L2SO4, where IA repents the dianion of iodanilic acid and L denotes 2, 2′-bipyridine (bpy); 4,4′-dimethy12,2′-bipyridine (Meo-bpy); 1,10-phenanthroline (phen); 4,7-diphenyl-l, 10-phenanthroline (Ph2-phen) and 5-nitro-1, 10-phenanthroline (NO2-phen), have been synthesized and characterized by elemental analyses, molar conductivity and roomtemperature magnetic moment measurements, IR and electronic spectral studies. It is proposed that these complexes have IA-bridged structures and consist of two oxovanadium(IV) ions each in a square pyramidal environment. The complexes (VO)2(IA) (bpy)2]SO4, (1) and[(VO)2( IA) (phen)2 ]SO4 (2) were further characterized by variable temperature (4.2–300 K) magnetic susceptibility measurements and the observed data were fitted to the modified Bleaney-Bowers equation by the least-squares method, giving the exchange integral J = - 2.15 m?1 for 1 and J = - 9.88 cm?1 for 2. This result indicates that there is a weak antiferromagnetic spin-exchange interaction between the two VO2+ ions within each molecule. 相似文献
2.
Synthesis,spectral characterization,and antidiabetic study of new furan-based vanadium(IV) complexes
《Journal of Coordination Chemistry》2012,65(3):511-524
We have synthesized furan-based vanadium complexes, bis(5-nitrofuran-2-carboxylato)oxovanadium(IV) – [VO(5NF)2], bis(1-furan-2-yl-ethanonato)oxovanadium(IV) sulfate – [VO(2AF)2]SO4, and bis(5-methyl-2-furalato)oxovanadium(IV) sulfate – [VO(MFFA)2]SO4 possessing [VO(O4)] coordination mode. These complexes are characterized by physico-chemical and spectroscopic methods. Based on electron paramagnetic resonance parameters, the proposed geometry is close to a distorted square pyramid. Animal study was carried out using standard protocol and the complete profile of glucose, protein, and total cholesterol levels were analyzed followed by an oral glucose tolerance test. 相似文献
3.
Gamil A.A. Al-Hazmi Khlood S. Abou-Melha Ismail Althagafi NashwaM. El-Metwaly Fathy Shaaban Mansour S. Abdul Galil Ashraf A. El-Bindary 《应用有机金属化学》2020,34(8):e5672
We have successfully synthesized new oxovanadium (IV) complexes with dimedone derivatives and their structure were confirmed by elemental analyses, spectroscopic techniques (FT-IR, UV–visible, EPR) and thermal analysis. The reaction of [VO (acac)2] with the azo dimedone ligands ( HL n ) produced mononuclear oxovanadium (IV) complexes with formula [VO (Ln)2]H2O. Results of the molar conductance proved that VO2+ complexes are non-electrolytes and fall in the range 14–16 Ω-1cm2mol−1. The coordination geometry of VO (IV) complexes is square-pyramidal, where vanadium (IV) ion is coordinated by oxygen atom of the carbonyl (C=O) group, and nitrogen atom of the deprotonating hydrazone moiety (–NH–), while the fifth position is occupied by an oxo group. Moreover, the optimized structure, bond angles, bond lengths, as well as the calculated quantum chemical parameters of the complexes have been estimated. DNA binding activities of the complexes were investigated using electronic absorption titration and viscosity measurements. The obtained results showed groove binding of the complexes to CT-DNA accompanied with a partial insertion of the ligand between the base stacks of the DNA with a binding constant of 2.07–5.51 x 105 M−1 range. Evaluation results of the synthesized complexes against the human cancer cell lines HepG-2 and MCF-7, as compared to the positive controls in the viability assay of vinblastine and colchicine have been reported. The in vitro anti-oxidant activity of all the complexes is determined by DPPH free radical-scavenging assay. Finally, the anti-microbial activities of the complexes have been investigated against fungal (Candida albicans), gram negative bacteria (Escherichia coli), and gram positive bacteria (Staphylococcus aureus) using the disc-diffusion method. 相似文献
4.
Six novel oxovanadium(IV) binuclear complexes have been synthesized and characterized, namely, [(VO)2(CA)L2]SO4 [L denotes 5-methyl-1,10-phenanthroline (Me-phen); 2,9-dimethyl-1,10-phenanthroline (Me2-phen); 5-chloro-1,10-phenanthroline (Cl-phen); diaminoethane (en); 1,3-diaminopropane (pn) and 1,2-diaminopropane (ap) respectively.], where CA represents the dianion of chloranilic acid. Based on elemental analyses, molar conductivity and room temperature magnetic moment measurements, IR and electronic spectral studies, it is proposed that there complexes have CA-bridged structures and consist of two vanadium(IV) ions in a square-pyramidal environment. The complexes [(VO)2(CA)(Me-phen)2]SO4 (1) and [(VO)2(CA)(Me2-phen)2]SO4 (2) were characterized by variable temperature magnetic susceptibility measurements (4~300 K) and the observed data were fitted to the modified Bleaney-Bowers equation by the least-squares method, giving the exchange integral J=-15.8 cm?1 for 1 and J=-10.6 cm?l for 2. This result indicates that there is a weak antiferromagnetic spin-exchange interaction between the two VO2+ ions within each molecule. 相似文献
5.
Six new μ-phthalato binuclear oxovanadium(IV) complexes, namely [(VO)2(PHTH)-(L)2]SO4 (L denotes 2,2′-bipyridine (bpy); 1,10-phenanthroline (phen); 4,4′-dimethyl-2,2′-bipyridine (Me2 bpy); 5-nitro-1,10-phenanthroline (NO2-phen); 5-chloro-1,10-phenanthroline (Cl-phen) and 5-methyl-1,10-phenanthroline (CH3-phen), where PHTH is the phthalate dianion), have been synthesized and characterized by elemental analyses, IR, electronic spectra, magnetic moments at room temperature and molar conductivity measurements. The temperature dependence of the magnetic susceptibility of complexes [(VO)2(PHTH)(phen)2]SO4 (1) and [(VO)2(PHTH)(CH3-phen)2]SO4 (2) was measured in 4—300 K range and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, ?=?2J?1·?2, giving the exchange integrals J=?12.8 cm?1 for 1 and J=?7.9 cm?l for 2. This indicates an antiferromagnetic spin-exchange interaction between the metal ions within each molecule. 相似文献
6.
Baojiao Gao Dandan Zhang Kunli Cui Ruikui Du 《Journal of Coordination Chemistry》2017,70(11):1835-1850
Two kinds of immobilized bidentate Schiff base oxovanadium(IV) complexes are prepared via polymer reactions and coordination reactions with chloromethylated cross-linked polystyrene (CMCPS) microspheres as matrix. Benzaldehyde (BA)-functionalized CPS microspheres, BA-CPS microspheres, were prepared through nucleophilic substitution with CMCPS microsphere as precursor and p-hydroxy benzaldehyde as reagent, and then Schiff base reactions were carried out with 3-aminopyridine (AP) and glycine (GL) as reagents, respectively, obtaining two kinds of bidentate Schiff base ligand-bonded microspheres, BAAP-CPS microspheres and BAGL-CPS microspheres. Finally, through coordination reactions with vanadyl sulfate (VOSO4) as reagent, the two kinds of immobilized bidentate Schiff base oxovanadium(IV) complex microspheres, CPS-[VO(BAAP)2] and CPS-[VO(BAGL)2], were obtained. The two immobilized complexes, VO(BAAP)2 and VO(BAGL)2, are N,N- and N,O-type bidentate Schiff base oxovanadium(IV) complexes and their ligands have different chemical structures. The two catalyst microspheres were used in oxidation of cyclohexanol and benzyl alcohol with molecular oxygen as oxidant and their catalytic activities are compared. The experimental results show that both solid catalysts can catalyze the transformation reactions of cyclohexanol and benzyl alcohol to their corresponding carbonyl compounds under mild conditions. However, CPS-[VO(BAAP)2] microspheres have much higher catalytic activity and better stability than CPS-[VO(BAGL)2] microspheres. For the immobilized bidentate Schiff base oxovanadium(IV) catalysts, the catalytic property is closely related to the chemical structures of the ligands, and for this, a theoretical explanation is given. 相似文献
7.
Sukhjinder Singh Madanmohan Singh Gill Rajendar D. Verma 《Journal of fluorine chemistry》1985,27(2):133-142
V(SO3CF3)3, VO(SO3CF3)2 and VO(SO3CF3)3 have been prepared by reacting V(O2CCF3)3, VO(O2CCF3)2 and VOC13 with HSO3CF3. The i.r. data suggest a bridging bidentate nature for SO3CF3 groups. The diffuse reflectance spectrum of V(SO3CF3)3 suggests hexacoordination of vanadium, whilst that of VO(SO3CF3)2 is comparable to either five or six coordinated oxovanadium (IV) systems. The magnetic moments of V(SO3CF3)3 and VO(SO3CF3)2 are slightly lower than the spin-only values. Thermal decomposition of these triflates is simple. All the three triflates form coordination complexes with pyridine, 2, 2′-bipyridyl and triphenylphosphine oxide. 相似文献
8.
A series of triazole‐derived Schiff bases (L1–L5) and their oxovanadium(IV) complexes have been synthesized. The chemical structures of Schiff bases were characterized by their analytical (CHN analysis) and spectral (IR, 1H and 13C NMR and mass spectrometry) data, and oxovanadium(IV) complexes were elucidated by their physical (magnetic susceptibility and conductivity), analytical (CHN analysis), conductance measurements and electronic spectral data. The molar conductivity data indicate the oxovanadium(IV) complexes to be non‐electrolyte. The Schiff bases act as bidentate and coordinate with the oxovanadium(IV)‐forming stoichiometry of a complex as [M (L‐H)2] where M = VO and L = L1–L5 in a square‐pyramidal geometry. The agar well diffusion method was used for in vitro antibacterial screening against E. coli, S. flexenari, P. aeruginosa, S. typhi, S. aureus and B. subtilis and for antifungal activity against T. longifucus, C. albican, A. flavus, M. canis, F. solani and C. glaberata. The biological activity data show the oxovanadium(IV) complexes to be more antibacterial and antifungal than the parent Schiff bases against one or more bacterial and fungal strains. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
9.
M. Asadi M. H. Ghatee S. Torabi K. Mohammadi F. Moosavi 《Journal of the Iranian Chemical Society》2010,7(4):1021-1035
The formation constants of some oxovanadium(IV) binary complexes containing Schiff bases resulting from condensation of salicylaldehyde with aniline and with its derivatives were determined spectophotometrically. The synthesized compounds were characterized by analytical and different physico-chemical techniques like 1H NMR, IR, elemental analysis, mass and UV-Vis spectral studies. The IR spectra affirm that coordination takes place through azomethine nitrogen and phenolate oxygen. Three of the VO(IV) Schiff base complexes i.e. bis(salicylideneaniline)oxovanadium(IV), [VO(L1)2], bis(salicylidene-4-methoxyaniline) oxovanadium (IV), [VO(L2)2] and bis(salicylidene-4-cyanoaniline)oxovanadium(IV), [VO(L10)2], were studied by thermogravimetry in order to evaluate their thermal stability and thermal decomposition pathways. The number of steps and, in particular, the starting temperature of decomposition of these complexes depends on the equatorial ligand. The complexes screened for antioxidant activity and the ab initio calculations were carried out to determine the structural and the geometrical properties of a typical vanadyl salicylideneaniline complex, [VO(L1)2]. 相似文献
10.
S. N. Thakur K. S. Yadav N. P. Singh H. S. Yadav 《Journal of the Iranian Chemical Society》2008,5(2):328-335
The oxovanadium(IV) complexes (I) of the type [VO(L)]SO4 have been prepared using an in-situ method of synthesis with ligands derived from di-2-thienylethanedione with 1,2-diaminobenzene or 2,3-diaminopyridine. These parent complexes have been further reacted with μ-diketones to yield macrocyclic complexes (II) of types [VO(mac)]SO4 (where mac = macrocyclic ligands derived by condensation of amino group of parent complex with μ-diketones), wherein the VO2+ cation acts as a template. Tentative structures of these complexes have been proposed on the basis of elemental analysis, electrical conductance, magnetic moments and spectral (infrared, electronic and electron spin resonance) data. The oxovanadium(IV) complexes are five coordinated wherein the tetraaza macrocyclic ligands act as tetradentate chelating agents. All the complexes are found to inhibit the infectivity of potato virus X, when checked using the test plant Chenopodium amaranticolor. 相似文献
11.
Winfried Plass 《无机化学与普通化学杂志》1997,623(8):1290-1298
Oxovanadium(IV) Complexes with Multidentate Amine Alcohol Ligands: Magneto-Structural Correlations for the {VO(μ-OR)2VO} Core The trivalent, pentadentate amine alcohol ligand 1,1-bis(2-hydroxyethyl)-4-(2-hydroxybenzyl)-1,4-diazabutane (H3hebab) reacts with [VO(acac)2] in methanol solution to yield the binuclear oxovanadium(IV) complex [{VO(Hhebab)}2] with a {VO(μ-OR)2VO}2+ core. The compound has been characterized by vibrational (IR, Raman), UV/Vis/NIR, and ESR spectroscopy and the measurement of the magnetic susceptibility in the temperature range of 2 to 280 K. A classification is given for the correlation of the configuration of the {VO(μ-OR)2VO} core and the magnetic properties of the related oxovanadium(IV) complexes. Antiferromagnetic interactions are operative in the case of anti-and syn-orthogonal as well as syn-coplanar configurations. whereas in the case of anti-coplanar and twist configurations ferromagnetic interactions are observed. Based on the antiferromagnetic behavior of [{VO(Hhebab)}2] with J = ?170 cm?1 this classification allows together with the spectroscopic data and density functional calculations the unequivocal assignment of an anti-orthogonal configuration for its {VO(μ-OR)2VO}2+ core. The structural and magnetic data of a series of oxovanadium(IV) complexes with anti- and syn-orthogonal {VO(μ-OR)2VO} core are used to investigate the quantitative correlation between the V(IV) …? V(IV) distance and the corresponding isotropic interaction constant J. 相似文献
12.
Kais A. K. Ebraheem Suhaila T. Hamdi Kahtan A. Asker Abdul-Wahab Al-Sadoon 《Monatshefte für Chemie / Chemical Monthly》1989,120(6-7):509-514
Summary The solvatochromic behaviour of bis(-diketonato)oxovanadium(IV) complexes is quantitatively correlated by an approach that models specific and non-specific solute-solvent interactions. The applicability of the Selbin-Gutmann relation is discussed. The solvent-induced spectral shifts in VO(acac)2 are dominated by specific interactions of the donor-acceptor type, whereas for VO(tfa)2, the nonspecific solute-solvent interactions make the dominant contribution.
Der Einfluß von Wechselwirkungen zwischen Lösungsmittel und gelöstem Stoff auf die VIS-Spektren von Bis(-diketonato)oxovanadium(IV)-Komplexen
Zusammenfassung Das solvatochrome Verhalten von Bis(-diketonato)oxovanadium(IV)-Komplexen wird mit einem Modell, das spezifische und nichtspezifische Wechselwirkungen in Lösung berücksichtigt, quantitativ beschrieben. Es wird die Anwendbarkeit der Selbin-Gutmann-Relation diskutiert. Die Solvens-induzierten Verschiebungen in den VIS-Spektren von VO(acac)2 werden von den spezifischen Wechselwirkungen vom Donor-Acceptor-Typ bestimmt, währenddessen für VO(tfa)2 die nichtspezifischen Wechselwirkungen zwischen Substrat und Lösungsmittel den dominierenden Beitrag liefern.相似文献
13.
Summary New carbodithioate complexes of the oxovanadium(IV), manganese(II) and manganese(III) ions have been prepared and studied by i.r. and electronic spectral and variable temperature magnetic susceptibility (77K to room temperature) measurements. The carbodithioate ligands, 4-methylpiperazine-1-carbodithioate (4-MPipzcdt) and 4-phenylpiperazine-1-carbodithioate (4-PPipzcdt), were derived from heterocyclic secondary amines. The VO(4-MPipzcdt)2 and VO(4-PPipzcdt)2 complexes possess C
4v
symmetry; Mn(4-PPipzcdt)2 is tetrahedral and Mn(4-PPipzcdt)3 is octahedral. All exhibit abnormal room temperature magnetic moments and the variable temperature magnetic moments suggest antiferromagnetism for the oxovanadium(IV) and the manganese(II) complexes and the occurrence of low spin (3
T
1g
) high spin (5
E
g
) equilibrium in addition to antiferromagnetic interactions in the manganese(III) complex. The spin-spin exchange parameter (-2J) value for the VO(4-MPipzcdt)2 complex has been calculated using variable temperature magnetic susceptibility data. 相似文献
14.
Summary The oxovanadium(IV) complexes [(VOSO4·H2O)2L] and [(VO)2L1(-SO4)] (L = hydrazone ligands derived from 1,4-dihydrazinophthalazine and benzaldehyde, 4-chlorobenzaldehyde, 4-methoxybenzaldehyde or acetophenone; L 1H2 = hydrazone ligands derived from 1,4-dihydrazinophthalazine and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxynaphthaldehyde) have been prepared and characterized by elemental analyses, electrical conductance, magnetic moments and spectral data. Reduced magnetic moments are observed for all sulfato-bridged derivatives, indicating antiferromagnetically coupled vanadium(IV) centres. The vanadium(IV) centres appear to have five-coordinated stereochemistries in the systems which involve two metals bound to each ligand. The thermal behaviour of the complexes was investigated by t.g. and d.t.g. techniques. The antifungal and antiviral activities of the hydrazones and their corresponding complexes were also investigated. The screening results have been correlated with the structural features of the tested compounds. 相似文献
15.
《Journal of Coordination Chemistry》2012,65(11):1143-1156
Condensation of 1,3-diaminopropane-2-ol with diacetylmonoxime, acetylacetone, salicylaldehyde and orthohydroxyacetophenone yielded the tetradentate Schiff bases N,N′-(2-hydroxy)propylenebis{(2-imino-3-oximino)butane} (H2dampnol), N,N′-(2-hydroxy)propylenebis(acetylacetoneimine) (H2acacpnol), N,N′-(2-hydroxy)propylenebis-(salicyalaldimine) (H2salpnol) and N,N′-(2-hydroxy)propylenebis(7-methylsalicylaldimine) (H2ohacpnol), respectively. The ligands form complexes with oxovanadium(IV), vanadium(IV) and oxovanadium(V) salts. Some mixed ligand complexes involving σ-bonded phenyl and benzyl radical along with tetradentate ligand, H2L (where, H2L stands for H2dampnol, H2acacpnol, H2salpnol or H2ohacpnol) of the types [(L)V(C6H5)2]CH3OH and [(L)V(CH2Ph)2]CH3OH have been synthesized, characterized and also provide the syntheses of some new organovanadium(IV) complexes. Silylation coupled with desilylation have been employed as a route to new organovanadium(IV) complexes. All the complexes have been characterized with the help of elemental analyses, molar conductance values, molecular weights, magnetic moments and spectroscopic (IR, UV-Vis, ESR) data. 相似文献
16.
Summary Vanadium(III) and oxovanadium(IV,V) paraand metasubstituted benzeneseleninato-complexes, formulated as V(XC6H4SeO2)3, VO(XC6H4SeO2)2 and V2O2(XC6H4SeO2)3Cl3 (where X = H, m-Cl, p-Cl, m-Br, p-Br, p-CH3), have been prepared. They have been characterized by elemental analyses, electrical conductance measurements, spectral (electronic and infrared) studies and magnetic susceptibility measurements. The i.r. results point to aO, O-seleninatocoordination for all the complexes; in addition, the presence of three SeO bands with the irreducible representation A2 + 2E in the i.r. spectra of the vanadium(III) derivatives suggests an octahedral configuration with D3 symmetry. The complexes of oxovanadium(IV) are five-coordinate with a tetragonal pyramidal geometry having the oxygen at the apex. As for the metal(V) derivatives a tentative stereochemistry of the complexes is proposed. 相似文献
17.
Ferdinand Belaj Angelika Basch Udo Muster 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(8):921-922
In the structure of the title compound, [VO(C2O4)(H2O)3]·2H2O, the V atom of the oxovanadium(IV) cation is coordinated to one bidentate oxalate anion and three water molecules, resulting in a neutral complex. Two more water molecules are not coordinated to the V atoms but are involved in the hydrogen‐bonding network, which consists of ten different hydrogen bonds. 相似文献
18.
Three novel oxovanadium(IV) Schiff base complexes [VO(Phen)(L)]SO4, where L = 4[(benzylidene)amino]antipyrine (Ia), 4[(cinnamalidene)amino]antipyrine (Ib) and 4[(2-chlorobenzylidene)amino]antipyrine
(Ic) are designed using benzaldehyde/cinnamaldehyde/2-chlorobenzaldehyde with 4-aminoantipyrine, 1,10-phenonthroline, and
vanadyl sulfate in the 1: 1: 1 molar ratio. They are synthesized by the template method. The geometry of the complexes is
elucidated by elemental analyses, IR, UV-Vis, ESR, CV, FAB mass, magnetic susceptibility, and conductance data. FAB mass spectrum
shows the degradation of the complexes. The electronic spectra of the complexes reveal their square pyramidal geometry in
which the ligands act as tetradentate. Their electrochemical parameters, the anodic and cathodic potentials, and the number
of electrons transferred are calculated. One quasi-reversible peak and one electron-transfer redox processes corresponding
to the formation of a VO(II)/VO(III) couple are observed. The antimicrobial activity of synthesized complexes are tested.
The results are compared with the standard penicillin. DNA cleavage experiments showed that Ia exhibits higher cleavage efficiency,
whereas Ib and Ic have the lower cleavage efficiency.
The text was submitted by the authors in English. 相似文献
19.
《Journal of Coordination Chemistry》2012,65(7):1228-1238
New non-oxovanadium(IV) complexes of biphenylphenols, [VCl2? n (bzac)2(OAr1,2) n ], have been synthesized in quantitative yields from the reaction of bis(benzoylacetonato)dichlorovanadium(IV) with the trimethylsilyl derivative of 2- and 4-phenylphenols in carbon tetrachloride. The complexes have been characterized by physicochemical, magnetic moment measurements, IR, mass spectra, and electrochemical studies. The thermal behavior of the complexes has been studied by TGA–DTA. The complexes have been screened for their antimicrobial activity against some pathogenic bacteria, Escherichia coli and Staphylococcus aureus and fungi, Candida albicans, Aspergillus niger, and Fusarium oxysporum, by two-fold serial dilution. 相似文献
20.
A new Schiff base hydrazone (Z)‐2‐(2‐aminothiazol‐4‐yl)‐N′‐(2‐hydroxy‐3‐methoxybenzylidene) acetohydrazide (H2L) and its chelates [VO (HL)2]·5H2O, [Cu (HL)Cl(H2O)]·2H2O and [Fe(L)Cl(H2O)2]·3H2O have been isolated and characterized using different physico‐chemical methods, for example infrared (IR), electron paramagnetic resonance (EPR), thermogravimetric analysis and DTG in the solid state, and 1H‐NMR, 13C‐NMR and UV in solution. Magnetic and UV–visible measurements proposed that the coordination environments are square pyramidal, tetrahedral and octahedral geometries for oxovanadium (IV), Cu (II) and Fe (III), respectively. The ligand acts as mono‐negative NO towards oxovanadium (IV) and Cu (II) ions, and bi‐negative ONO for Fe (III) ion. The geometries of the ligand and its complexes were performed using Gaussian 9 program with density functional theory. The EPR spectral data of oxovanadium (IV) and Cu (II) chelates confirmed the mentioned geometries. The molecular modeling was done, and illustrated bond lengths, bond angles, molecular electrostatic potential, Mulliken atomic charges and chemical reactivity for the inspected compounds. Theoretical IR and 1H‐NMR of the free ligand were calculated. Furthermore, thermodynamic and kinetic parameters for thermal decomposition steps were studied. Docking study of H2L was applied against the proteins of both bacterial strains Staphylococcus aureus and Escherichia coli, as well as the protein of xanthine oxidase as antioxidant agent by Schrödinger suite program utilizing XP glide protocol. Furthermore, antimicrobial, antioxidant and DNA‐binding activities of the compounds have been carried out. 相似文献