• Mycobiology
• /
• 제34권4호
• /
• pp.214-218
• /
• 2006

Four copper(II) complexes have been prepared using macrocyclic ligands. The macrocyclic ligands have been synthesized by the condensation reaction of diethyl phthalate with Schiff bases derived from o-phenylene diamine and Knoevenagel condensed ${\beta}-ketoanilides$ (obtained by the condensation of acetoacetanilide and substituted benzaldehydes). The ligands and copper complexes have been characterized on the basis of Microanalytical, Mass, UV-Vis., IR and CV spectral studies, as well as conductivity data. On the basis of spectral studies, a square-planar geometry for the copper complexes has been proposed. The in vitro antifungal activities of the compounds were tested against fungi such as Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans. All the synthesized copper complexes showed stronger antifungal activities than free ligands. The minimum inhibitory concentrations (MIC) of the copper complexes were found in the range of $8{\sim}28\;{\mu}g/ml$. These compounds represent a novel class of metal-based antifungal agents which provide opportunities for a large number of synthetic variations for modulation of the activities.

• Mycobiology
• /
• 제35권2호
• /
• pp.65-68
• /
• 2007

Three novel complexes of Cu(II), Co(II) and Zn(II) using a macrocyclic ligand derived by the condensation of diethylphthalate and benzidine have been designed, synthesized and characterized by UV-Vis., IR, Mass and Elemental analyses data in order to find out their antifungal activities. The stoichiometry of the complexes has been found to be 1:1 (Metal: Ligand). The analytical data indicate that the complexes exhibit square-planar geometry. The antifungal activity of the macrocyclic ligand and its metal complexes has been screened in vitro against fungi such as Aspergillus niger, A. flavus, Trichoderma harizanum, T. viridae and Rhizoctonia solani.

• Bulletin of the Korean Chemical Society
• /
• 제33권7호
• /
• pp.2279-2286
• /
• 2012

The template synthesis of copper(II) and nickel(II) complexes derived from 2,6-diformyl-4-methylphenol with diethylenetriamine or 1,2-bis(3-aminopropylamino)ethane produce the 12-membered $N_3O$ and 17-membered $N_4O$ macrocyclic complexes, respectively. The geometry of the complexes has been determined with the help of electronic and EPR spectroscopic values and found to be five coordinated square pyramidal and, six coordinated distorted tetragonal for 12-membered and 17-membered macrocyclic complexes, respectively. Electrochemical studies of the mononuclear $N_3O$ and $N_4O$ copper(II) complexes show one irreversible oneelectron reduction wave at $E_{pc}=-1.35$ and -1.15 V respectively, and the corresponding nickel(II) complexes show irreversible one-electron reduction wave at $E_{pc}=-1.25$ and -1.22 V, respectively. The nickel(II) complexes show irreversible one-electron oxidation wave at $E_{pa}=+0.84$ and +0.82 V, respectively. All the complexes were evaluated for in vitro antimicrobial activity against the human pathogenic bacteria and fungi.

• Bulletin of the Korean Chemical Society
• /
• 제22권5호
• /
• pp.523-526
• /
• 2001

• Bulletin of the Korean Chemical Society
• /
• 제12권2호
• /
• pp.219-224
• /
• 1991

New binuclear Ni(Ⅱ) and Cu(Ⅱ) complexes with various alkyl derivatives of 1,2-bis(1,3,6,8,10,13-hexaaza-1-cyclotetradecyl) ethane, in which two fully saturated 14-membered hexaaza macrocyclic subunits are linked together by an ethylene chain, have been synthesized by the one step template condensations of formaldehyde with ethylenediamine and appropriate primary alkyl amines in the presence of the metal ions. Each macrocyclic subunit of the double-ring macrocyclic complexes contains one alkyl pendant arm and has a square planar geometry with a 5-6-5-6 chelate ring sequence. The visible spectra and oxidation properties indicate that the metal-metal interaction of the binuclear complexes are not significant. Synthesis, characterization, and the properties of the complexes are presented.

• Bulletin of the Korean Chemical Society
• /
• 제15권5호
• /
• pp.374-378
• /
• 1994

Square planar nickel(II) complexes with various 1-alkyl derivatives of the 14-membered pentaaza macrocycle 8-methyl-8-nitro-1,3,6,10,13-pentaazacyclotetradecane can be readily prepared by two-step metal template condensation reactions of ethylenediamine, nitroethane, formaldehyde, and appropriate primary alkylamines. In coordinating solvents the nickel (II) complexes form octahedral species containing two axially coordinated solvent molecules and thus show square planar-octahedral equilibrium. The properties of the pentaaza macrocyclic complexes are considerably different from those of the complexes of analogous hexaaza and tetraaza macrocyclic complexes. Synthesis, characterization, and spectroscopic and chemical properties of the new complexes are described.

• Bulletin of the Korean Chemical Society
• /
• 제33권8호
• /
• pp.2517-2522
• /
• 2012

New polynuclear poly(hexaaza macrocyclic) copper(II) complexes $[1](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$, $[2](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$, and $[3](ClO_4)_{2n}{\cdot}(H_2O)_{2n}$ have been prepared by the one-pot reaction of formaldehyde with ethylenediamine and 1,2-bis(2-aminoethoxy)ethane, 1,3-diaminopropane, or 1,6-diaminohexane in the presence of the metal ion. The polymer complexes contain fully saturated 14-membered hexaaza macrocyclic units (1,3,6,8,10,13-hexaazacyclotetradecane) that are linked by $N-(CH_2)_2-O-(CH_2)_2-O-(CH_2)_2-N$, $N-(CH_2)_3-N$, or $N-(CH_2)_6-N$ chains. The mononuclear complex $[Cu(H_2L^5)](ClO_4)_4$ ($H_2L^5$ = a protonated form of $L^5$) bearing two $N-(CH_2)_2-O-(CH_2)_2-O-(CH_2)_2-NH_2$ pendant arms has also been prepared by the metal-directed reaction of ethylenediamine, 1,2-bis(2-aminoethoxy)ethane, and formaldehyde. The polymer complexes were characterized employing elemental analyses, FT-IR and electronic absorption spectra, molar conductance, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and scanning electron micrograph (SEM). Electronic absorption spectra of the complexes show that each macrocyclic unit of them has square-planar coordination geometry with a 5-6-5-6 chelate ring sequence. The polymer complexes as well as $[Cu(H_2L^5)]^{4+}$ are quite stable even in concentrated $HClO_4$ solutions. Synthesis and characterization of the polynuclear and mononuclear copper(II) complexes are reported.

• 대한화학회지
• /
• 제55권6호
• /
• pp.912-918
• /
• 2011

Tetraaza Schiff base macrocyclic ligands, $L^1$,$L^2$ and their transition metal chelates have been synthesized and characterized by elemental analyses, IR, electronic, EPR and $^1H$ NMR spectra, TGA and magnetic measurements. The molar conductance of one milli-molar solution of the complexes measured in DMF indicates that the divalent metal complexes are nonelectrolyte while those of trivalent metal ion, are 1:1 electrolytic in the same solvent. The reduction of Racah parameter from the free ion value confirms the presence of considerable covalence of metal ligand sigma bond in the Co(II) and Mn(II) complexes. The EPR spectra of Cu(II) complexes at room temperature shows axial symmetry indicating a $d_x{^2}_{-y}{^2}$ ground state with significant covalent character. The thermal analysis suggests that the complexes do not contain water molecules because only the metal is left as residue.

• Bulletin of the Korean Chemical Society
• /
• 제34권6호
• /
• pp.1913-1916
• /
• 2013

• Bulletin of the Korean Chemical Society
• /
• 제25권3호
• /
• pp.403-406
• /
• 2004