• Journal of the Korean Chemical Society
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• v.34 no.5
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• pp.404-412
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• 1990

The time resolved electron spin resonance spectroscopy are used to two measurement methods of chemically induced dynamic electron polarization (CIDEP) and absorption ESR. The spectra of the semiquinone radical anion were successively detected in the laser flash photolysis of anthraquinone in the mixtures of 2-propanol and triethylamine. The semiquinone radical anion was fairly stable and its cw ESR could be observed. The rate constant (T1$^{-1}$) of the spin-depolarization of polarized semiquinone radical anion was 2.6 ${\times}\;1-^5$ sec$^{-1}$ and the decay of the radical anion was the first order with the rate constant (K$_1}$) of 300.0 sec$^{-1}$. The intensity of CIDEP spectra increased with the increasing the microwave power, but the Torrey wiggles appeared following with decay curves.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.19-27
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• 2011

New series of Mn(II), Ni(II), Co(II), Cu(II) and Zn(II) of the 2-(benzothiazol-2-yl)-N'-(2,5-dihydroxybenzylidene) acetohydrazide have been synthesized and characterized by elemental analysis, IR, UV-vis, $^1H$-NMR, mass and ESR spectra, magnetic susceptibility and molar conductivity measurements. The spectral data and magnetic measurements of the complexes indicate that, the geometries are either square planar or octahedral. The biological activity of the ligand and its complexes against fungi (Aspergillus nigar and Fusarium oxysporium) were investigated. The metal complexes exhibited higher activity than both the parent ligand and the corresponding metal ion.

• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.603-611
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• 2011

Ethoxylacetyl oxime ligands [HL, (1) and $H_2L^1$, (3)] react with copper(II) acetate monohydrate yield octahedral and square planar complexes, respectively. The complexes have been postulated due to elemental analyses, IR, UVVis. spectra, magnetic susceptibility, conductivity and ESR spectra. Molar conductance of the complexes in DMF indicates a non-ionic character. The ESR spectra of [$(L)_2Cu(H_2O)_2$], (2) complex at room temperature and 77K are characteristic of an axial symmetry ($d_{x2-y2}$) with covalent bond character and have a large line width typical of dipolar interactions. However, [$(L^1)Cu$], (4) complex in the solid state showed spectra of marked broadening and loss of hyperfine splitting confirming spinexchange interactions between the copper(II) sites. The spectrum of the doped copper(II) complex at room temperature showed super-hyperfine splitting from coordinated nitrogen atoms and it has an axial type ($d_{x2-y2}$) with covalent bond character and an essentially square-planar arrangement around the copper(II) ion. The spectrum of [$(L^1)Cu$], (4) in frozen methanol at 77K was characteristic of the triplet state of a dimer species and the distance found between the two copper(II) centers was calculated and is equal to 4.8 ${\AA}$.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.307-314
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• 1986

Cu(II) binding mechanisms with water soluble organic fractions (WSOF) extracted from an agricultural soil (W), a soil treated with sludge for 6 years ($WS_6$), a sludge-soil mixture incubated for one week ($WS_1$), and sewage sludge (SS) were studied by electron spin resonance (ESR) spectroscopy and potentiometric titrations. Cu(II)-WSOF complexes produced $g_{11}$ values which were larger than $g_{\perp}$ values, indicating that the coordination of Cu(II) complex was an elongated octahedron. At liquid $N_2$ temperature (77K), the Cu(II)-W complex showed an anisotropic ESR spectrum while the Cu(II)-SS complex showed an isotropic spectrum. These spectral results suggest that the oxygen donor ligands of W may form relatively strong bonds with $Cu^{2+}$ due to extensive chelation while ligands of SS may form little or no chelate bonds with $Cu^{2+}$. The ESR spectra of Cu(II)-SS complex also suggest that each of four in-plane ligands (e.g., $COO^-$, $H_2O$, $Cl^-$, etc.) may act independently as monodentate ligands. Oxygen donor ligands such as aromatic carboxyl groups were probably the major Cu(II) binding sites in W. Sulfonate, aliphatic carboxyl group, and N-containing ligands were probably the major binding sites in SS at pH 5. The Cu(II) complexation with N-containing groups increased as sludge was added to the soil. Much higher (6x) pyridine concentrations were required to displace W from Cu(II)-W complex as compared to the Cu(II)-SS complex.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.418-429
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• 2011

Novel chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), ruthenium(III), and zirconyl(II) complexes of $N^1,N^2$-bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl)phthalamide ($H_4L$, 1) have been synthesized and characterized by elemental, physical, and spectral analyses. The spectral data showed that the ligand behaves as either neutral tridentate ligand as in complexes 2-5 with the general formula $[H_4LMX_2(H_2O)]{\cdot}nH_2O$ (M=Cu(II), Ni(II), Co(II), X = Cl or $NO_3$), neutral hexadentate ligand as in complexes 10-12 with the general formula $[H_4LM_2Cl_6]{\cdot}nH_2O$ (M=Fe(III), Cr(III) or Ru(III)), or dibasic hexadentate ligand as in complexes 6-9 with the general formula $[H_2LM_2Cl_2(H_2O)_4]{\cdot}nH_2O$ (M = Cu(II), Ni(II), Co(II) or Mn(II), and 13 with general formula $[H_4L(ZrO)_2Cl_2]{\cdot}8H_2O$. Molar conductance in DMF solution indicated the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complexes 2, 5, and 6 showed $g_{\parallel}$ >g> $g_e$, indicating distorted octahedral structure and the presence of the unpaired electron in the $N^1,N^2$ orbital with significant covalent bond character. For the dimeric copper(II) complex $[H_2LCu_2Cl_2(H_2O)_4]{\cdot}3H_2O$ (6), the distance between the two copper centers was calculated using field zero splitting parameter for the parallel component that was estimated from the ESR spectrum. The antibacterial and antifungal activities of the compounds showed that, some of metal complexes exhibited a greater inhibitory effect than standard drug as tetracycline (bacteria) and Amphotricene B (fungi).