• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2017-2020
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• 2009

Three complexes, [bis(L-, D- and DL-alaninato)(diaqua)]nickel(II) di-hydrate, were prepared and characterized by X-ray crystallography, gas chromatography, UV-Visible spectroscopy and isothermal calorimetry. Small deviations from the 50:50 distribution of the enantiomers assigned to chiral preferences of the ligands in the complexes were observed. The surprising and unexpected results indicate that complexing alanine with nickel(II) ion alters the racemization rates of D and L isomers of the amino acid. The precipitated complex due to change in pH resulted in preferential precipitation of one isomer with respect to the other. It has been observed that this alternation is ogmented by the long time span which would result in preferential protein forming from the L-isomer. Although the results are bizarre and perplexing, they are fascinating and sound scientifically.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.475-476
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• 2006

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.249-252
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• 2009

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.1053-1056
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• 2007

• Journal of the Korean Chemical Society
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• v.46 no.3
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• pp.213-218
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• 2002

(${\eta}$5-Cyclopentadienyl)(${\eta}$6-1,2,3,4-tetramethyl-1,4-dibora-2,5-cyclohexadiene)Ni (5) was synthe-sizedas a main product by the reaction of cyclopentadienyl(carbonyl)nickel dimer and 1,2,3,4-tetramethyl-1,4-di-bora-2-cyclohexene (1). Di-allyl nickel reacted with 2,3-diethyl-1,4-di-methyl-1,4-dibora-2-cyclohexene (2) at -20$^{\circ}C$ to give bis(${\eta}$6-2,3-diethyl- 1,4-dimethyl-1,4-dibora-2,5-cyclohexadiene)nickel (6) in the yield of 15%. By the reaction of di-allyl nickel and 2,3-dimethyl-1,4-diethoxy-1,4-di- bora-2-cyclohexene (3) at -20$^{\circ}C$ bis[${\eta}$6-2,3-dim-ethyl-1,4-diethoxy-1,4-di- bora-2,5-cyclohexadiene]nickel (7) was obtained in 22% yield. These double-decker complexes were difficult to separate because of their unstabilities and were identified by ESR, NMR, MS and ele-mental analysis, etc.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1757-1763
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• 2004

A new series of nickel(II), cobalt(II)/(III) and copper(II) complexes of 14, 15 and 16-membered of macrocyclic ligands have been prepared and characterized by elemental analyses, IR, UV-VIS and $^1H-NMR$ spectra, magnetic susceptibilities, conductivities, DTA and ESR measurements. Molar conductances in DMF solution indicate that, the complexes are nonelectrolytes except (9-12) complexes. The electronic spectra show that, all complexes are square planar or distorted octahedral geometry. The ESR spectra of solid complexes (4), (8) and (11) show square planar of axial type symmetry $(d_{x2-y2})$ with considerable covalent bond character. However, complex (12) shows a spectrum of octahedral geometry with $d_{z2}$ ground state. Complex (12) shows exploitation in reducing the amount of electron adducts formed in DNA during irradiation with low radiation products.

• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.189-198
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• 2011

In the present paper two new thiosemicarbazones i.e., 4[N-(4'-ethylbenzalidene)amino]antipyrine thiosemicarbazone (EBAAPTS) and 4[N-(2',4'-dimethylbenzalidene)amino]antipyrine thiosemicarbazone (DMBAAPTS) have been synthesized and characterized. The complexing abilities of these thiosemicarbazones i.e. EBAAPTS and DMBAAPTS towards cobalt(II) and nickel(II) salts have been explored. The reactions of the hot ethanolic solutions of cobalt(II) and nickel(II) salts with EBAAPTS and DMBAAPTS led to the formation of the novel complexes of general composition [$MX_2(L)H_2O$] (M=$Co^{2+}$ or $Ni^{2+}$; X=$Cl^-$, $Br^-$, $NO_3^-$, $NCS^-$ or $CH_3COO^-$; L=EBAAPTS or DMBAAPTS). The newly synthesized complexes have been characterized by elemental analyses, molar mass, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. The molar conductance measurements of the complexes in nitrobenzene correspond to their non-electrolytic nature. All the complexes are of high-spin type. On the basis of spectral studies an octahedral geometry has been assigned for Co(II) and Ni(II) complexes of the type [$MX_2(L)H_2O$]. These complexes were screened for their antibacterial and antifungal activities on different species of pathogens, fungi and bacteria and their biopotency has been discussed.

• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.523-526
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• 2001

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.206-212
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• 1993

Syntheses and properties of zwitterionic dithiocarbamates and their nickel(Ⅱ) complexes are described. The complexes have been characterized by mass infrared and electronic absorption spectroscopy, and conductivity measurement. Ni(Ⅱ)-dithiocarbamato complexes are soluble in polar solvents such as water, methanol, and acetone etc. The possible structures were proposed on the basis of elemental analyses and physical properties.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.499-505
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• 2007

Monomeric complexes of nickel(II) having terdentate bis(imino)aryl ligands (N,C,N-pincer) are reported. New complexes (2,6-(ArN=CH)2C6H3)NiBr (Ar=2,6-dimethylphenyl (1), 2,6-diisopropylphenyl (2)) have been synthesized through oxidative addition of 1,3-(ArN=CH)2C6H3Br (bis(N-Ar)-2-bromoisophthalaldimine: Ar=Ph-2,6-Me2, Ph-2,6-iPr2) to Ni(COD)2 (COD=1,5-cyclooctadiene), in high yields. The development of a synthetic route to ligands and nickel complexes is outlined. The complexes were characterized by IR, 1H-NMR and elemental analysis. Full characterization of complexes 1 and 2 is discussed. An investigation into the catalytic activity of the complexes in ethylene polymerization was performed, resulting in no formation of polyethylenes but producing a small amount of oily oligomers. Preliminary results indicate that the pincer complexes were found to be inactive as catalysts in ethylene polymerization.