Sharif Digital Repository

The title complex was synthesized and structurally characterized by single-crystal X-ray diffraction. This complex was solved in the triclinic system, space group P1, with the following unit-cell parameters: a = 8.5657(4)Å, b = 10.9848(5)Å, c = 13.1681(6)Å, α = 112.617(1)°, β = 99.646(1)°, δ = 90.849(1)°, Z = 2, V = 1123.28(9)Å3. The final R value was R1 = 0.0344 for 15675 measured reflections. 2008 © The Japan Society for Analytical Chemistry  

The title complex has been synthesized and structurally characterized by single-crystal X-ray diffraction. This complex has a dinuclear structure where two copper(II) ions are bridged by two bent alkoxo groups. The citrate acts as a tetradentate ligand coordinating via three carboxylates and an alkoxo groups in which one of three carboxylates is coordinated weakly. The coordination geometry around the Cu(II) is strongly distorted square pyramidal. The distance between the two copper atoms is 2.8386(3)Å. 2007 © The Japan Society for Analytical Chemistry  

A series of new ternary zinc(II) complexes [Zn(L1-10)(phen)], where phen is 1,10-phenanthroline and H2L1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, l-phenylalanine, l-valine, l-alanine, and l-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δν (νas(COO) - νs(COO)) of 191-225 cm-1, indicating a monodentate coordination of the carboxylate group. Spectral data... 

New water-soluble zinc(II) Schiff-base complexes derived from amino acids (glycine, L-phenylalanine, and L-valine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5- sulfonate) have been synthesized. The complexes were characterized by elemental analysis, IR, electronic, 1H NMR, and 13C NMR spectra. In the IR spectra of the complexes, the large difference between the asymmetric νas(COO) and symmetric νs(COO) carboxylate stretch, Δν(νas(COO)-νs(COO)) of 199-247 cm-1, indicates monodentate coordination of the carboxylate group. Spectral data showed that in these complexes the ligand is a tridentate ONO moiety, coordinating to the metal... 

Water-soluble cobalt(II) tetradentate Schiff base complexes have been shown to form charge transfer (CT) complexes with a series of nucleoside monophosphates including adenosine-5′-monophosphate (AMP) and cytidine-5′-monophosphate (CMP). The investigated water-soluble cobalt(II) Schiff base complexes are (i) disodium[{bis(5-sulfo-salicylaldehyde)-o-phenylenediiminato}cobalt(II)], Na 2[Co(SO3-salophen)] (1); (ii) disodium[{bis(5-sulfo-salicylaldehyde)-4,5-dimethyl-o-phenylenediiminato} cobalt(II)], Na2[Co(SO3-sal-4,5-dmophen)] (2) and (iii) disodium[{bis(4-methoxy-5-sulfo-salicylaldehyde)-4, 5-dimethyl-o-phenylenediiminato}cobalt(II)], Na2[Co(SO 3-4-meosal-4,5-dmophen)] (3). The formation... 

The symmetrical and unsymmetrical Schiff base complexes of VO(IV) and Mn(III) derived from 2,2′-diaminobiphenyl and derivatives of salicylaldehyde and 1-hydroxy-2-napnthaldehyde have been synthesized and characterized by elemental analysis, NMR, infrared and electronic absorption spectroscopies, and conductivity measurements. The reaction of the ligands with oxovanadium(IV) was found to be kinetically unfavored, probably due to the small ionic radius of the metal ion, which is not in accordance with the cavity size of the ligands. Copyright © 2005 Taylor & Francis, Inc  

The formation constants for 1:1 molecular complex formation between water-soluble cobalt(II) tetradentate Schiff base complex, disodium[{bis(4- methoxy-5-sulfo-salicylaldehyde)-4,5-dimethyl-o-phenylenediiminato}cobalt(II)], Na2[Co(SO3-4-meosal-4,5-dmophen)], and nucleotides, adenosine-5′-triphosphate (ATP) and cytidine-5′-triphosphate (CTP), in mixed solvent systems of ethanol and water with different volume fractions of ethanol and water have been determined spectrophotometrically at constant ionic strength (I = 0.2 mol dm-3 NaClO4) and temperature 278 K. Trends in the values of formation constants according to the volume fractions of ethanol and water in ethanol and water mixed solvent... 

Novel non-symmetrical tetradentate Schiff base complexes with N2O2 and N3O donor sites have been obtained using the half-unit N-(1-hydroxy-2-acetonaphthone)-1-amino-2-phenyleneimine (HL). Two reaction pathways have been used (i) preparation of the free ligand which is then reacted with the desired metal salt, and (ii) template synthesis without isolation of the free ligand. The prepared nickel and copper complexes have been characterized by elemental analyses, conductance, IR, UV, and 1H NMR spectroscopy  

Mn-doped ZnO nanoparticles, Zn1−xMnxO, were synthesised by a polyethylene glycol (PEG) sol–gel method and the physicochemical properties of compounds were characterised by atomic absorption spectroscopy (AAS), energy-dispersive X-ray analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The catalytic degradation of an organic dye, methylene blue (MB), in the presence of Zn1−xMnxO as the catalyst and hydrogen peroxide (H2O2) as the oxidant at room temperature in water has been studied. Effects of oxidant, catalyst amount, catalyst composition, pH value of the solution and an OH-radical... 

This article describes the synthesis and characterization of electronegative oxovanadium(IV) complexes containing tetradentate Schiff-base ligands derived from condensation of 1,3-propanediamine and 1,8-naphthylamine with 5-bromo-3-nitro-2-hydroxybenzaldehyde. New VOL1: [VO(5-Br-3-NO2salnaph)] and VOL2: [VO(5-Br-3-NO2salpn)] complexes were obtained in orange polymeric form with (V=O) stretching bands at 884 and 876 cm-1, respectively. The orange VOL1 and VOL2 complexes turn dark brown and green, respectively, when ground thoroughly in mortars. X-ray powder diffraction patterns of the ground VOL1 complex (VOL1g) scarcely show diffraction peaks. The data suggest that the linear chain polymeric... 

Charge-transfer (CT) complexes formed from the reactions of 4-nitropyrocatechol (4-nCat) as an electron acceptor with four amino alcohols: 2-aminoethanol, 1-amino-2-propanol, 4-aminobutanol and N-(2-hydroxyethyl)-1,3-diaminopropane (NHEDAP) as electron donors, have been studied spectrophotometrically in H2O and H2O/EtOH at 20, 25, 30, 35 and 40 °C. The calculated values of the oscillator strength and transition moment confirm the formation of CT-complexes. The thermodynamic and spectroscopic parameters were also evaluated for the formation of CT-complexes. The equilibrium constants ranged from 9.00 to 2.20 l mol-1 (M-1). These interactions are exothermic and have relatively large standard... 

In the title compound, the dihedral angles between the 2-amino-5-chloro- pyridyl rings and the pyridine ring are 56.26 (6)° and 78.83 (5)°; the angle between the 2-amino-5-chloro-pyridyl rings is 72.42 (5)°. The solvent water mol-ecules are linked to the organic compound by N - H⋯O, O - H⋯O, N - H⋯N and O - H⋯N hydrogen bonds. π⋯π Stacking inter-actions are also observed between the 2-amino-5-chloro-pyridyl rings (centroid⋯centroid distance = 3.243 Å). © 2008  

This article describes the synthesis and characterization of oxovanadium(IV) complexes containing tetradentate Schiff-base ligands derived from condensation of ethylenediamine, meso-1,2-diphenyl-1,2-ethylenediamine, 1,2-orthophenylenediamine and 1,2-cyclohexanediamine with 5-bromo-3-nitro-2- hydroxybenzaldehyde. The novel VOL1:[VO(5-Br-3-NO2salen)], VOL2:[VO(5-Br-3-NO2saloph)] and VOL3:[VO(5-Br- 3-NO2salchxn)] complexes were obtained in orange polymeric form with (V=O) stretching bands at 878, 884 and 884 cm-1, respectively, but the VOL4 complex was obtained as a green monomer with (V=O) stretching band at 978 cm-1. The redox process in acetonitrile was reversible for VOL4 and E° was... 

This article describes the synthesis and characterization of two novel, as well as four previously reported, Schiff base complexes of oxovanadium(IV) and the study of their catalytic reactivity in the aerobic oxidation of olefins. The novel (5-Br-3-NO2salen) and (5-Br-3-NO2meso-stein) ligands were, respectively, synthesized from condensation of 5-bromo-3-nitro-2-hydroxybenzaldehyde with ethylenediamine or meso-1,2-diphenyl-1,2-ethylenediamine. The reaction of these ligands with VO(acac)2 readily resulted in the synthesis of their oxovanadium(IV) complexes [VO(5-Br-3-NO2salen)] and [VO(5-Br-3-NO2meso- stein)], respectively. The novel ligands and complexes were deliberately designed to... 

A series of previously reported mononuclear Cu(II) and homodinuclear Cu(II)Cu(II) complexes, as well as, novel mononuclear Cu(II), homodinuclear Cu(II)Cu(II), and heterodinuclear Cu(II)Ni(II) complexes of a phenol-based dinucleating ligand with two different N(amine)2O2 and N(imine)2O2 coordination sites, were synthesized and characterized by elemental analyses, infrared and electronic absorption spectroscopies and conductivity measurements. The electrochemical behavior and catecholase-like activity of the complexes were also studied using cyclic voltammetry and UV-vis spectrophotometry, respectively. Our results show that the dinuclear complexes are more effective catalysts in the oxidation... 

Circular dichroism (CD) spectroscopy, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the interaction between copper(II) complex of compartmental Schiff base ligand (L), N,N′-bis(3-hydroxysalicylidene)ethylenediamine, and bovine serum albumin (BSA) in 0.1 mol dm-3 phosphate buffer solution adjusted to physiological pH 7.0 containing 20% (w/w) dimethylsulfoxide at room temperature. CD spectra show that the interaction of the copper(II) complex with BSA leads to changes in the α-helical content of BSA and therefore changes in secondary structure of the protein with the slight red shift (2 nm) in CD spectra. From the voltammetric data, i.e. changes in... 

Conditions for an efficient ligand-free Heck C-C coupling reaction of aryl iodides and bromides with terminal olefins under aerobic conditions have been developed. Critical to the success of this new protocol is the use of palladium acetate as an extremely active catalyst for the Heck reaction in water and aqueous media. Both the base and the solvent were found to have a fundamental influence on the efficiency of the reaction, with K2CO3 and a mixture of (2:1) H2O/DMSO being the optimal base and solvent, respectively  

In the title compound [systematic name: 2-(3,4-dihydroxy-phen-yl) ethanaminium perchlorate], C8H12NO2 +·ClO4 -, the cations and anions are linked into three-dimensional structure via inter-molecular N - H⋯O and O - H⋯O hydrogen bonds. © 2008  

Reaction of the binucleating S-protected ligand precursors 2-(N,N-dimethylthiocarbamato)-5-methylisophthalaldehyde di-2′-hydroxy anil (I) and 2-(N,N-dimethylthiocarbamato)-5-methylisophthalaldehyde di-2′-hydroxy 5′-methyl anil (II) with nickel(II) acetate tetrahydrate in the presence of pyrazole afforded the binuclear nickel(II) complexes [LINi2(pz)] (1) and [LIINi2(pz)] (2), respectively. The complexes have been characterized by routine physicochemical studies as well as by X-ray single crystal structure analysis. In both complexes, Ni(II) ions are doubly bridged by the thiophenolic sulfur of the pentadentate Schiff base ligand and a pyrazolate group. Efficient protocols for the oxidation... 

A polymeric manganese(II) complex with the general formula [Mn(O 2CCH2NH2CH2CO2) 2(H2O)2]n from reaction of iminodiacetatic acid and manganese(II) perchlorate under nitrogen in water, was synthesized and characterized. The structure of the complex was determined using single-crystal X-ray diffraction, elemental analysis, IR and UV-vis spectra. This complex exhibited excellent catalytic activity and selectivity for oxidation of various alcohols and sulfides to the corresponding aldehydes/ketone and sulfoxides using urea hydrogen peroxide and oxone (2KHSO 5·KHSO4·K2SO4), respectively, as oxidants under air at room temperature. The easy preparation, mild reaction conditions, high yields of the...