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Synthesis, characterisation and antimicrobial activities of cobalt(II), copper(II) and zinc(II) mixed-ligand complexes containing 1,10-phenanthroline and 2,2’-bipyridine
M.O. Agwara, P.T. Ndifon, N.B. Ndosiri, A.G. Paboudam, D.M. Yufanyi, A. Mohamadou
Bulletin of the Chemical Society of Ethiopia , 2010,
Abstract: Three new 1,10-phenanthroline and 2,2’-bipyridine mixed-ligand complexes of [Co(bpy)(phen)2](NO3)2.2H2O, [Cu(bpy)(phen) H2O)2]Cl2.2H2O, and [Zn(bpy)2(phen)]Cl2.6H2O were synthesized. The complexes were characterized by elemental, IR and visible spectroscopic analyses and the results indicate that both ligands are coordinated to the respective metal ions giving octahedral complexes. Antimicrobial studies showed that there is increased antimicrobial activity of the metal ions on coordination to the ligands. The water soluble complexes showed antimicrobial activities that are higher than those of the metal salts and 2,2’-bipyridine but lower than those of 1,10-phenanthroline. The copper complex [Cu(bpy)(phen)(H2O)2]Cl2.2H2O shows the highest activity. KEY WORDS: 1,10-Phenanthroline, 2,2’-Bipyridine, Mixed-ligand complexes, Antimicrobial activities, Cobalt(II), Copper(II), Zinc(II) Bull. Chem. Soc. Ethiop. 2010, 24(3), 383-389.
Transition metal complexes with thiosemicarbazide-based ligands. Part46. Synthesis and physico-chemical characterization of mixed ligand cobalt(III)-complexes with salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine
VUKADIN M. LEOVAC,LJILJANA S. VOJINOVIC,KATALIN MéSZáROS SZéCSéNYI,VALERIJA I. CESLJEVIC
Journal of the Serbian Chemical Society , 2003,
Abstract: Mixed ligand octahedral cobalt(III) complexes with the tridentate salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine of general formula [CoIII(L11-3)(py)3]X (H2L1 = salicylaldehyde semicarbazone, X = [CoIICl3(py)]-, ClO4- . H2O, I- . 0.5 I2; H2L2 = salicylaldehyde thiosemicarbazone, X = [CoIICl3(py)]-, [CoIIBr3(py)]-, ClO4- . H2O, I3-; H2L3 = salicylaldehyde S-methylisothiosemicarbazone, X = [ CoIIBr3(py) ]-, ClO4- . H2O, BF4-) were synthesized. The tridentate coordination of all the three dianionic forms of the ligands involves the phenol oxygen, hydrazine nitrogen and the chalcogen (O or S) in case of salicylaldehyde semi-, thiosemicarbazone and the terminal nitrogen atom in the case of isothiosemicarbazone. For all the complexes, a meridial octahedral arrangement is proposed, which is a consequence of the planarity of the chelate ligand. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility, IR and electronic absorption spectra. The thermal decomposition of the complexes was investigated by thermogravimetry, coupled TG-MS measurements and DSC.
Synthesis, characterisation and antimicrobial activities of cobalt(II), copper(II) and zinc(II) mixed-ligand complexes containing 1,10-phenanthroline and 2,2’-bipyridine
M.O. Agwara,P.T. Ndifon,N.B. Ndosiri,A.G. Paboudam
Bulletin of the Chemical Society of Ethiopia , 2010,
Abstract: Three new 1,10-phenanthroline and 2,2’-bipyridine mixed-ligand complexes of [Co(bpy)(phen)2](NO3)2.2H2O, [Cu(bpy)(phen) H2O) 2]Cl2.2H2O, and [Zn(bpy)2(phen)]Cl2.6H2O were synthesized. The complexes were characterized by elemental, IR and visible spectroscopic analyses and the results indicate that both ligands are coordinated to the respective metal ions giving octahedral complexes. Antimicrobial studies showed that there is increased antimicrobial activity of the metal ions on coordination to the ligands. The water soluble complexes showed antimicrobial activities that are higher than those of the metal salts and 2,2’-bipyridine but lower than those of 1,10-phenanthroline. The copper complex [Cu(bpy)(phen)(H2O) 2]Cl2.2H2O shows the highest activity.
Synthesis, Spectroscopy, and Magnetic Characterization of Copper(II) and Cobalt(II) Complexes with 2-Amino-5-bromopyridine as Ligand  [PDF]
Raziyeh Arab Ahmadi,Farshideh Hasanvand,Giuseppe Bruno,Hadi Amiri Rudbari,Saeid Amani
ISRN Inorganic Chemistry , 2013, DOI: 10.1155/2013/426712
Abstract: The synthesis, spectroscopic, and magnetic characterization of two new copper(II) and cobalt(II) complexes are described. Both two compounds have the general formula [M(L)2(Cl)2], in which 2-amino-5-bromopyridine. These complexes were prepared in one-step synthesis and characterized by elemental analysis, FTIR, UV-Vis, and EPR spectroscopy. Moreover, the single crystal structure of complex (1) was studied by the X-ray diffraction method. This compound consists of mononuclear units consisting of two ligands linked to metal via the nitrogen of pyridine ring. The UV-Vis spectra of copper(II) and cobalt(II) complexes show three and five absorption bands, respectively, attributed to the d-d transition of the metal ion, ligand → metal charge transfer, and or transitions of the ligand. The FTIR spectra show MN2Cl2 vibrations at 500–300 . The complexes show room temperature magnetic moments of 1.78?BM and 4.12?BM for Cu(II) and Co(II), respectively. The X-band electron spin resonance (ESR) spectra of Cu(II) complex in DMF or DMSO frozen at liquid nitrogen temperature show the typical transition. 1. Introduction The study of transition metal ion complexes by magnetic and optical techniques has furnished a considerable body of empirical data, much of which can be understood in terms of the phenomenological ligand field theory [1]. The major portion of this data is primarily concerned with complexes containing a single paramagnetic transition metal ion; relatively little information is available on dimeric and trimeric coordination complexes [2]. Since copper(II) ions are widely distributed in biological systems, a significant amount of research has centered on the search for relatively simple copper(II) complexes which may display some of the properties of the metalloproteins. One such system of potential importance is that formed by copper(II) halides with pyridine and substituted pyridines [3]. Small low-molecular-weight copper(II) coordination complexes with N-donor ligands have frequently been used to model the active site in copper proteins with the aim of obtaining insight into the correlation between structure and the spectroscopic and magnetic behavior [4–7]. Cobalt(II) complexes are important in biology mainly because of coenzyme B12 [8]. A report of insulin-like action of cobalt(II) chloride implies that such metal complexes may have similarities with vanadium compounds, which exhibit insulin-like effects [9–16]. Electronic properties of cobalt(II) compounds have received substantial attention [17–19] in part due to the fact that many of these complexes
Synthesis, characterization and biological activity of symmetric dinuclear complexes derived from a novel macrocyclic compartmental ligand
Mruthyunjayaswamy, B.H.M.;Ijare, Omkar B.;Jadegoud, Y.;
Journal of the Brazilian Chemical Society , 2005, DOI: 10.1590/S0103-50532005000500016
Abstract: a phenol based novel macrocyclic binucleating compartmental ligand n,n-bis(2,6-diiminomethyl-4-methyl-1-hydroxyphenyl)malonoyldicarboxamide was prepared. the complexes were prepared by template method by reacting 2,6-diformyl-4-methylphenol, malonoyl dihydrazide and the metal chlorides of cu(ii), ni(ii), co(ii), cd(ii), zn(ii) and hg(ii) in methanol to get a series of dinuclear complexes. the complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibility data, ir, uv-vis, esr, nmr and fab mass spectral data. the dinuclear nature of the complexes was confirmed on the basis of elemental analyses, magnetic susceptibility, esr and fab mass spectral data. the ligand as well as cu(ii), ni(ii), co(ii) and zn(ii) complexes were tested for their antibacterial and antifungal properties against escherichia coli, staphyloccocus aureus, aspergillus niger and fusarium oxysporum. magnetic susceptibility measurements of cu(ii), ni(ii) and co(ii) complexes reveal that these complexes exhibit antiferromagnetic coupling behavior due to the presence of two metal ions in close proximity. fab mass spectrum of the cu(ii) complex gave a clear evidence for the dinuclear nature. the ligand and the complexes were found to be less active against the tested bacteria, but the ligand alone was found active against the fungus fusarium oxysporum.
SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON MIXED LIGAND COMPLEXES OF CO (II), NI (II) AND CU (II) WITH ISOXAZOLE SCHIFF BASE AND 1, 10-PHENANTHROLINE/ 2, 2' -BIPYRIDINE LIGANDS Synthese, Charakterisierung und antimikrobiellen STUDIES ON MIXED Ligand-Komplexe von Co (II), Ni (II) und Cu (II) MIT Isoxazol SCHIFF BASE AND 1, 10-Phenanthrolin / 2, 2 '-Bipyridin-Liganden
R.Shakru, N.J.P.Subhashini, Shivaraj
Heterocyclic Letters , 2011,
Abstract: Synthesis, Characterization and antimicrobial studies of Cobalt (II), Nickel (II) and Copper (II) ternary complexes of mixed ligands with Schiff base derived from 3-amino 5-methyl isoxazole with 2-hydroxy 1-naphthaldehyde and 1, 10-phenanthroline/ 2, 2' bipyridine. The micro analytical, magnetic moment, IR and electronic spectral data analysis have been used to confirm the structure of these complexes, their lower electrical conductance values indicates that all the complexes are non- electrolytes. The magnetic moment values and electronics spectral data of the Co (II) and Ni (II) complexes further indicates the octahedral geometry and Cu (II) complexes are tetragonal geometry. The synthesized compounds have been tested against microorganisms such as (bacillus and pseudomonas) bacteria and (R.Saloni and A. niger) fungi. A comparative study of the MIC (minimum inhibitory concentration) values of the ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligand and control.
Use of the 2-Pyridinealdoxime/N,N′-Donor Ligand Combination in Cobalt(III) Chemistry: Synthesis and Characterization of Two Cationic Mononuclear Cobalt(III) Complexes  [PDF]
Konstantis F. Konidaris,Catherine P. Raptopoulou,Vassilis Psycharis,Spyros P. Perlepes,Evy Manessi-Zoupa,Theocharis C. Stamatatos
Bioinorganic Chemistry and Applications , 2010, DOI: 10.1155/2010/159656
Abstract: The use of 2-pyridinealdoxime (paoH)/N, -donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao (L-L) , where L-L = 1,10-phenanthroline (phen) and 2, -bipyridine (bpy). The CoC /paoH/L-L (1?:?2?:?1) reaction system in MeOH gives complexes [C (pao (phen)]Cl 2 O (1 2 O) and [C (pao (bpy)]Cl 1.5MeOH (2 1.5MeOH). The structures of the complexes were determined by single-crystal X-ray crystallography. The C ions are six-coordinate, surrounded by three bidentate chelating ligands, that is, two pa and one phen or bpy. The deprotonated oxygen atom of the pa ligand remains uncoordinated and participates in hydrogen bonding with the solvate molecules. IR data of the complexes are discussed in terms of the nature of bonding and the known structures. 1. Introduction Oximes and their metal complexes are of current interest because of their rich physicochemical properties, reactivity patterns, and potential applications in many important chemical processes in the fields of medicine [1, 2], bioorganic chemistry [3], catalysis [4], and electrochemical and electrooptical sensors [5]. In the treatment of organophosphate insecticide toxicity in man and animals, the use of acetylcholinesterase reactivators in conjunction with atropine has been found to be the most effective treatment [6]. Among various acetylcholinesterase reactivators, 2-pyridinealdoxime (paoH) is routinely used in human and veterinary practices. It is furthermore known that metal complexes of active drugs as ligands can have important pharmaceutical activities because of several factors. In fact, the field of medicinal inorganic chemistry emerged a long time ago [7], and it is based on certain principles that can be summarized as follows. Complexation with the metal protects the drug against enzymatic degradations because of the inertness of certain metal-ligand linkages. The metal complex can have better hydrophobicity/hydrophilicity properties than the free ligand and, through this, it can improve the transport processes in the tissues. In addition, the metal complex can release the active drug(s) in a specific organ, and its activity can be reinforced by the combination of effects from the ligands and from the metal residue. The application of these principles has already resulted in the design of successful metal-based drugs [8, 9]. Since 1905, when Tschugaeff introduced dimethylglyoxime as a reagent for the analysis of nickel, oxime ligands have played an important role in the continuing progress of coordination
Modification on Synthesis of Mixed Ligand Chelates by Using Di- and Trivalent Transition Metal Ions with Schiff Base as Primary Ligand  [PDF]
Abdussalam Ali Maihub, Faten Suliman Alassbaly, Marei Mailoud El-Ajaily, Abdunnaser Mohamed Etorki
Green and Sustainable Chemistry (GSC) , 2014, DOI: 10.4236/gsc.2014.43015
Abstract:

New mixed ligand chelates synthesized from di-and trivalent metal ions (Cr, Co, Ni, and Cu ions) and Schiff base (L1) resulted from the condensation of 4-dimethylaminobenzaldehyde with 2-aminophenol as primary ligand, whereas 2-nitroaniline (L2) represents the secondary ligand in a molar ratio of M:L1:L2 [1:1:1]. The synthesized Schiff base and chelates have been characterized by using several tools, such as, elemental analysis, molar conductivity, magnetic moment measurements, infrared and electronic spectra. The mass spectra of the ligands and Ni(II) chelate were used to justify the process of modification, as well as, the electron paramagnetic resonance spectrum which was carried out for Cu(II) chelate all in order to elucidate the chemical and geometrical structure of the chelates. On the basis of the obtained data, the geometry of the products was proposed for all the chelates.

Synthesis and characterization of a tetraaza macrocyclic ligand and its cobalt(II), nickel(II) and copper(II) complexes  [PDF]
SULEKH CHANDR,MONIKA TYAG,SWATI AGARWAL
Journal of the Serbian Chemical Society , 2010,
Abstract: Co(II), Ni(II), and Cu(II) complexes with a tetradentate nitrogen donor [N4] macrocyclic ligand, viz. 6,15-dimethyl-8,17diphenyl-7,16-dihydrodibenzo[b,i][1.4.8.11]tetraazacyclotetradecine, were synthesized. Their structures were determined based on elemental analyses, molar conductance and magnetic susceptibility measurements, and IR, 1H-NMR (ligand) and electronic spectral studies. Based on analytical and molar conductance data, the complexes may be formulated as [M(L)Cl2] and [M’(L)]Cl2 (where M = Co(II) and Cu(II), and M’ = Ni(II)) due to their non-electrolytic and 1:2 electrolytic nature. Based on spectral studies, an octahedral geometry was assigned for the Co(II) complex, whereas square-planar and tetragonal geometry were proposed for the Ni(II) and Cu(II) complexes, respectively. The synthesized ligand and its complexes were screened for fungicidal activity against two pathogenic fungi (i.e., Fusarium moniliformae and Rhizoctonia solani) to assess their growth inhibiting potential.
New Cobalt-Mediated Radical Polymerization (CMRP) of Methyl Methacrylate Initiated by Two Single-Component Dinuclear β-Diketone Cobalt (II) Catalysts  [PDF]
Feng Bao,Lingling Feng,Jie Gao,Zhifang Tan,Bin Xing,Rui Ma,Chunjie Yan
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0013629
Abstract: Two dinuclear cobalt complexes based on bis-diketonate ligands (ligand 1: 3,3′-(1,3-phenylene)bis(1-phenylpropane-?1,3-dione);ligand 2: 3,3′-(1,4-phenylene)bis(1-phenylpropane-?1,3-dione))were successfully synthesized. The two neutral catalysts all showed satisfactory activities in the cobalt-mediated radical polymerization (CMRP) of methyl methacrylate (MMA) with the common initiator of azodiisobutyronitrile (AIBN). The resulting polymerizations have all of the characteristics of a living polymerization and displayed linear semilogarithmic kinetic plots, a linear correlation between the number-average molecular weight and the monomer conversion, and low polydispersities. Mono- or dicomponent low polydispersity polymers could be obtained by using the two dinuclear catalysts under proper reaction conditions. All these improvements facilitate the implementation of the acrylate CMRP and open the door to the scale-up of the syntheses and applications of the multicomponent low polydispersity polymers.
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