scholarly journals Synthesis, Spectroscopic, and Electrochemical Studies on Some New Copper(II) Complexes Containing 2-{[(Z)-Phenyl (Pyridine-2-yl) Methylidene] Amino}Benzenethiol and Monodentate Ligands

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
S. P. Rawat ◽  
M. Choudhary

Five new mononuclear copper(II) complexes, namely, [Cu(L)(ImH)]·ClO41; [Cu(L)(Me-ImH)]·ClO42; [Cu(L)(Et-ImH)]·ClO43; [Cu(L)(2-benz-ImH)]·ClO44; [Cu(L)(benz-ImH)]·ClO45, where HL = 2-{[(Z)-phenyl (pyridine-2-yl) methylidene] amino} benzenethiol; ImH = Imidazole; Me-ImH = Methy-limidazole; Et-ImH = Ethyl-imidazole; 2-benz-ImH = 2-methyl-benzimidazole; benz-ImH = benz-imidazole, have been synthesized and characterized by various physicochemical and spectroscopic techniques. Magnetic moments, electronic spectra, and EPR spectra of the complexes suggested a square planar geometry around Cu(II) ion. The synthesized HL ligand behaves as monobasic tridentate Schiff base bound with the metal ion in a tridentate manner, with N2S donor sites of the pyridine-N, azomethine-N, and benzenethiol-S atoms. The redox behaviour of the copper complexes has been studied by cyclic voltammetry. Superoxide dismutase activity of these complexes has been revealed to catalyse the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed.

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5316
Author(s):  
Néstor Novoa ◽  
Carolina Manzur ◽  
Thierry Roisnel ◽  
Samia Kahlal ◽  
Jean-Yves Saillard ◽  
...  

We have recently reported a series of neutral square planar tridentate Schiff base (L) complexes of the general formula [(L)M(py)], showing relatively high first-order hyperpolarizabilities and NLO redox switching behavior. In the present study, new members of this family of compounds have been prepared with the objective to investigate their potential as building blocks in the on-demand construction of D-π-A push–pull systems. Namely, ternary nickel(II) building blocks of general formula [(LA/D)Ni(4-pyX)] (4–7), where LA/D stands for an electron accepting or donating dianionic O,N,O-tridentate Schiff base ligand resulting from the monocondensation of 2-aminophenol or its 4-substituted nitro derivative and β-diketones R-C(=O)CH2C(=O)CH3 (R = methyl, anisyl, ferrocenyl), and 4-pyX is 4-iodopyridine or 4-ethynylpyridine, were synthesized and isolated in 60–78% yields. Unexpectedly, the Sonogashira cross-coupling reaction between the 4-iodopyridine derivative 6 and 4-ethynylpyridine led to the formation of the bis(4-pyridyl) acetylene bridged centrosymmetric dimer [{(LD)Ni}2(µ2-py-C≡C-py)] (8). Complexes 4–8 were characterized by elemental analysis, FT-IR and NMR spectroscopy, single crystal X-ray diffraction and computational methods. In each compound, the four-coordinate Ni(II) metal ion adopts a square planar geometry with two nitrogen and two oxygen atoms as donors occupying trans positions. In 8, the Ni…Ni separation is of 13.62(14) Å. Experimental results were proved and explained theoretically exploiting Density Functional Theory calculations.


2019 ◽  
Vol 11 (1) ◽  
pp. 60 ◽  
Author(s):  
Festus Sunday Fabiyi ◽  
Adesoji Alani Olanrewaju

Six new Mn(II), Fe(II), Co(II), Ni (II), Cu(II) and Zn(II) complexes with benzoic acid (L) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (L1), of the molecular formulae [MnLL1]·H2O (1), [FeLL1]·H2O (2), [CoLL1] (3), [NiLL1]·H2O (4), [CuLL1] (5) and [ZnLL1] (6), respectively, have been synthesized. The molecular structures of the complexes were determined by spectrophotometric studies using ir, 1H and 13C nmr, es and mass spectrophotometry revealed that the geometries of the complexes 1, 2, 3, and 6 are tetrahedral, while 4 and 5 have square planar geometry. These geometries were supported by their magnetic moments data. The coordination of the ligands to the metal ion are through their oxygen atoms. TGA studies showed that they are thermally stable. Their antioxidant studies revealed that they are good antioxidants.


Author(s):  
Zhe An ◽  
Jing Gao ◽  
William T. A. Harrison

The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′)bis(sparfloxacin-κ2O,O′)manganese(II) dihydrate, [Mn(C8H4O4)(C19H22F2N4O3)2(H2O)0.25]·2H2O or [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O, (I), and bis(sparfloxacin-κ2O,O′)copper(II) benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O3)2](C8H4O4)·2H2O or [Cu(Hspar)2](bdc)·2H2O, (II), are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate). The Mn2+ion in (I) is coordinated by twoO,O′-bidentate Hspar neutral molecules (which exist as zwitterions) and anO,O′-bidentate bdc dianion to generate a distorted MnO6trigonal prism. A very long bond [2.580 (12) Å] from the Mn2+ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II), the Cu2+ion lies on a crystallographic inversion centre and a CuO4square-planar geometry arises from its coordination by twoO,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I) and (II) feature intramolecular N—H...O hydrogen bonds, which closeS(6) rings. In the crystals of both (I) and (II), the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.


2016 ◽  
Vol 13 (2) ◽  
pp. 105-114
Author(s):  
Baghdad Science Journal

New metal ion complexes were synthesized with the general formula; K[PtLCl4], [ReLCl4] and K[ML(Cl)2] where M = Pd(II), Cd(II), Zn(II) and Hg(II), from the Azo ligand (HL) [2-Hydroxy-3-((5-mercapto-1,3,4-thiadiazol-2-yl)diazenyl)-1-naphth aldehyde] (HL) the ligand was synthesized from (2-hydroxy-1-naphthaldehyde) and (5-amino-1,3,4-thiadiazole-2-thiol). The ligand and its metal complexes are characterized by phisco- chemical spectroscopic techniques (FT.IR, UV-Vis and Mass spectra, elemental analysis, molar conductivity, Atomic Absorption, Chloride contain and magnetic susceptibility). The spectral data suggest that the (HL) behaves as a bidentate ligand in all complexes. These studies revealed tetrahedral geometries for all metal complexes, except square planar for Pd(II) complex and except octahedral geometry for Pt(IV) and Re(V) complexes. The study of complexes formation via molar ratio of (M:L) as (1:1). Theoretical treatment of this ligand and its metal complexes in gas phase using Hyper chem.8 was preformed.


2011 ◽  
Vol 76 (1) ◽  
pp. 75-83 ◽  
Author(s):  
A.S. Ramasubramanian ◽  
Ramachandra Bhat ◽  
Ramakrishna Dileep ◽  
Sandya Rani

Transition metal complexes of 5-bromosalicylidene-4-amino-3- mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II), Ni(II), Co(II) and Pd(II), were synthesized and characterized by physicochemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II) and Ni(II) complexes were assigned octahedral geometries, while the Cu (II) and Pd(II) complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2- methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO) and molecular oxygen as co-oxidants. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.


1980 ◽  
Vol 33 (4) ◽  
pp. 737 ◽  
Author(s):  
M Palaniandavar ◽  
C Natarajan

Metal(II) bis-chelates of the type ML2 [M = CoII, NiII, CuII; L = 2'- hydroxy-5'-X-chalcone where X = H, CH3, Cl] have been prepared and studied. Structures have been assessed by the measurement of magnetic moments, ligand field and infrared spectra and thermal properties. These chelates possess low-spin trans-square-planar configuration and show resistance to adduct formation in contrast to metal(II) chelates of β-diketones, salicylaldehyde, o-hydroxyaryl ketones and esters and o-hydroxy-crotonophenones, which have high-spin octahedral configuration. Extensive conjugation lowers the energy of the π3* orbital which enters into a very strong dπ-π3* interaction leading to spin-pairing. ��� Infrared spectra indicate that the carbonyl group is perturbed only slightly by coordination to metal. A change in metal ion affects v(C=O), v(M-O) and other vibrations and the order of stability, namely, Co ≈ Ni < Cu, inferred from these vibrations is as expected for the low-spin square configuration of the chelates. Introduction of substituents (5'-X) alters only v(M-O) significantly and the order of stability, namely, Cl > CH3 > H, derived from v(M-O) is consistent with Taft's resonance polar parameters of the substituents. All these observations are explained by the electron sink property of the phenyl group.


1970 ◽  
Vol 23 (3) ◽  
pp. 491 ◽  
Author(s):  
AT Phillip ◽  
AT Casey ◽  
CR Thompson

The new polyamine ligand 1,8-bis(2'-pyridyl)-3,6-diazaoctane has been synthesized for the first time by the reaction between 2-vinylpyridine and ethyl-enediamine. The ligand could not be distilled without decomposition and hence it was purified by converting it into the crystalline copper(11) perchlorate complex, from which the ligand was liberated by the reaction with sodium sulphide solution. The pure ligand was obtained in an overall yield of 28%, based on starting materials. The complexes formed by the ligand with the metal ions copper(11), nicke1(11), palladium(11), zinc(11), and cobalt(111) were isolated and characterized by physical measurements of their conductance in solution, magnetic moments, infrared and electronic absorption spectra. The ligand adopts the planar-N4 configuration around the metal ion in the complexes with copper(11), nicke1(11), and palladiurn(11), whereas it probably adopt's a tetrahedral-N4 configuration around the zinc(11) complex ion. The nickel(11) perchlorate complex is diamagnetic in the solid state and it most likely contains the metal ion in square-planar cordination. When dissolved in coordinating solvents, this complex undergoes a reversible, temperature-dependent equilibrium between diamagnetic and solvated, paramagnetic forms.


2004 ◽  
Vol 59 (6) ◽  
pp. 655-660 ◽  
Author(s):  
Pritha Talukder ◽  
Amitabha Datta ◽  
Samiran Mitra ◽  
Georgina Rosair

The title compounds, [Cu(C16H23N2O)SCN] (1) and [Cu(C16H23N2O)N3] (2), containing a tridentate Schiff base ligand, which is the 1:1 condensation product of benzoylacetone and 2- diethylaminoethylamine, have been synthesised and their crystal structures determined. The structure of 1 is based on a four coordinate copper centre with square-planar geometry formed by the N2O donor set of the Schiff base and an N atom of the thiocyanate anion. A similar arrangement occurs in 2 with the N2O donor set of the Schiff base and an N atom of the azide anion. The Cu-N and Cu-O distances are 1.924(8), 2.073(8), 1.927(9) and 1.910(6)Å , for 1 and 1.960(4), 2.050(4), 1.935(4) and 1.907(3) for 2, respectively.


2017 ◽  
Vol 13 (2) ◽  
pp. 1-15
Author(s):  
Rita Bhattacharjee Virupaiah Gayathri

A series of palladium(II) halo complexes of the types [PdX 2 L 2 ].nH 2 O {n = 0, X = Cl, L = L 2 , L 4 and L 5 ; X = Br, L = L 2 ; n = 1, X = Cl, L = L 1 and L 3 } and Pd 2 X 4 L 3 [X = Br, L = L 1 , L 3 , L 4   and L 5 ] were prepared where L is 6-R-5,6- dihydrobenzoimidazo quinazoline (R-Diq; where R = ethyl: L 1 / n or i-propyl: L 2 , L 3 / n or i-butyl: L 4 , L 5 ) and characterized by elemental analyses, conductivity measurements, TGA, infrared, electronic, NMR and mass spectral techniques. Based    on these studies monomeric/dimeric structure with a square planar geometry around the metal ion was proposed for all the complexes. Some of the complexes were investigated for anti-microbial activity.


2010 ◽  
Vol 428-429 ◽  
pp. 140-143
Author(s):  
Chung Jung Chen ◽  
Chung K. Lai

A new type of 3,3'-(2-hydroxypropane-1,3-diyl) bis(azan-1-yl-1-ylidene)bis(2-(4-alkoxy phenyl)prop-1-en-1-ol) and their copper complexes were prepared and mesomorphic properties characterized. The mesomorphic properties of these copper complexes were studied by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and powder X-ray diffraction. X-ray structural crystallographic analysis showed that these bimetallic compounds have two copper centers coordinated with central square planar geometry. These molecules all have total two 1a or five alkoxy sidechains 1b appended around the central core. The mesomorphic behavior exhibited was found to be dependent on the sidechain density. All compounds in 1a exhibited smectic mesophases, however, compounds in 1b exhibited hexagonal columnar phases (Colh), which were characterized by optical textures and confirmed by powder x-ray diffraction.


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