• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.506-514
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• 2010

A new series of ligands N-[(benzoylamino)-thioxomethyl]-amino acid (HL) were synthesized by reaction of benzoylisothiocyanate with various amino acids namely aspartic acid [BATA] (1), glutamic acid [BATG] (2), methionine [BATM] (3), leucine [BATL] (4), and tryptophan [BATT] (5). The ligands were characterized by elemental analysis, IR and NMR spectra. Some transition metal complexes ($ML_2$) for these ligands (6-8) were prepared; [M=Cu(II), Co(II), or Ni(II)], and characterized by elemental analysis, IR and $^1H$ NMR spectra. Antibacterial study showed that all the ligands have no antibacterial activity, whereas ($ML_2$) complexes; [M = Cu(II), Co(II), or Ni(II)] have antibacterial activity towards (Gram -ive) Escherichia (NCTC5933) and (Gram +ive) Staphylococcus (NCTC6571) and have no toxicity on (BALB/C) Albino mice.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.54-61
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• 2019

In this study, a magnetic adsorbent was synthesized by growing ferrite nanoparticles substituted with metals (Me = Co, Mn, Ni) on zeolite 4A for the efficient separation of waste adsorbents present in the solution after the adsorption of Cu(II). The metal ferrite grown on the surface of zeolite was prepared by solvothermal synthesis. Characteristics of the magnetic adsorbent were analyzed by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and physical property measurement system (PPMS). The saturation magnetization of the A type zeolite coated with Co-ferrite (CFZC) was the highest at 5 emu/g and the Cu(II) adsorption performance was also excellent. The adsorption results of Cu(II) on CFZC were well fitted by the Langmuir model at 298 K. Also, the adsorption of Cu(II) on CFZC follows a pseudo-second order kinetic. The Gibbs free energy values (${\Delta}G^0$) ranging from -4.63 to -5.21 kJ/mol indicates that the Cu(II) adsorption is spontaneous in the temeprature range between 298 and 313 K.

• Resources Recycling
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• v.31 no.3
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• pp.73-80
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• 2022

Reduction smelting of spent lithium-ion batteries at high temperature produces metallic alloys. Following solvent extraction of the leaching solutions of these metallic alloys with either sulfuric or hydrochloric acid, the raffinate is found to contain Ni(II), Co(II), Mn(II), and Si(IV). In this study, two cationic exchange resins (Diphonix and P204) were employed to investigate the loading behavior of these ions from synthetic sulfate and chloride solutions. Experimental results showed that Ni(II), Co(II), and Mn(II) could be selectively loaded onto the Diphonix resin from a sulfate solution of pH 3.0. With a chloride solution of pH 6.0, Mn(II) was selectively loaded onto the P204 resin, leaving Ni(II) and Si(IV) in the effluent. Elution experiments with H₂SO₄ and/or HCl resulted in the complete recovery of metal ions from the loaded resin.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.340-344
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• 2006

• Analytical Science and Technology
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• v.12 no.6
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• pp.498-503
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• 1999

Co(II), Ni(II), and Cu(II) complexes with tetradentate schiff base-$NOTDH_2$, were synthesized. The structures of these complexes were characterized by elemental analysis, IR, UV-visible, NMR spectra, and thermogravimetric analysis. The mole ratio of schiff base($NOTDH_2$) to the metal(II) at complexes was found to be 1:1. Cu(II) complexes were four-coordinated configuration, while Co(II) and Ni(II) complexes were hexacoordinated configuration containing two water molecules and all complexes were non-ionic compounds.

• Journal of the Korean Chemical Society
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• v.23 no.2
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• pp.59-64
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• 1979

The dipole moments for octahedral $[M(II)Cl_2N_2O_2]$, square planar and tetrahedral $[Pd(II)X_2Y_2]$ type complexes are calculated, using the approximate molecular orbital theory [M(II) = Ni(II) or Co(II), X = N and Y = O or S]. The calculated dipole moments for these complexes are in reasonable agreement with the experimental values. The possible structures for these complexes are investigated on the basis of the calculated dipole moments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.95-104
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• 2018

The structures and energies of the anhydrate and hydrate (hydrate rate: h of 1) states of L-alanine (LA) and glycine (G) were calculated by quantum chemical calculations (QCCs) using B3LYP/6-31G(d,p) for four types of conformers (${\beta}$-extended: ${\Phi}/{\Psi}=t-/t+$, $PP_{II}$: g-/t+, $PP_{II}$-like: g-/g+, and ${\alpha}$-helix: g-/g-). In LA and G, which have an imino proton (NH), three conformation types of ${\beta}$-extended, $PP_{II}$-like, and ${\alpha}$-helix were obtained, and water molecules were inserted mainly between the intra-molecular hydrogen bond of $CO{\cdots}HN$ in $PP_{II}$-like and ${\alpha}$-helix, and attached to the CO group in ${\beta}$-extended. In LA and G, $PP_{II}$-like conformers were most stable in the anhydrate and hydrate states, and the result for LA was different from some experimental and theoretical results from other studies reporting that the main stable conformation of alanine oligopeptide was $PP_{II}$. The formation pattern and stability of the conformation of the oligopeptide was strongly dominated by the presence/absence of intra-molecular hydrogen bonding of $CO{\cdots}HN$, or the presence/absence of an $NH_2$ group in the starting amino acid.

• Bulletin of the Korean Chemical Society
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• v.17 no.1
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• pp.80-83
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• 1996

• Journal of the Korean Chemical Society
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• v.32 no.6
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• pp.520-527
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• 1988

The crystal structures of $Co^{2+}\;and\;Ag^+\;exchanged\;zeolite\; A,\; Ag_6Co_3$-A(a = 12.131(5)$\AA$) and $Ag_3Co_{4.5}$-A(a = 12.145(1)$\AA$), have been determined by single crystal X-ray diffraction techniques. Both structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$. Full-matrix leastsquares refinement converged to the final error indices of R1 = 0.045 and R2 = 0.041 for $Ag_3Co_{4.5}-A,\; and\; R1 = 0.066\; and\; R2 = 0.076\; for\; Ag_6Co_3$-A using the 258 and 189 reflections, respectively, for which I > 3$\sigma$(I). Both structures indicate that CO(Ⅱ)ions are coordinated by three framework oxygens; the Co(II) to O(3) distances are 2.118(4)$\AA$ for $Ag_3Co_{4.5}$-A and 2.106(1)$\AA$ for $Ag_6Co_3-A$, respectively. In each structure, the angle substended at Co(II), O(3)-Co(II)-O(3) is ca 120°, close to the idealized trigonalplanar value. $Co^{2+}$ ions prefer to 6-ring sites and $Ag^+$ ions prefer to 8-ring site when total number of cations is more than 8. The crystals of hydrated and dehydrated $Ag_{12-2x}Co_x-A (x > 4.5)$ had no crystalline diffraction pattern, indicating the apparent exchange limit of $Co^{2+}\; into\; Ag_{12}-A\; is\; 4.5 Co^{2+}$ ions per unit cell. $Co^{2+}$ ions hydrolyze $H_2O$ molecules and $H_3O^+$ concentraction is accumulating. These $H_3O^+$ ions destroy the zeolite structures.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.19-20
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• 2000

We have developed the 12.1" SVGA reflective type color TFT-LCD(Thin Film Transistor - Liquid Crystal Display) with the high aperture ratio and well designed reflector for the applications such as mini note PC, Note PC and electronic book. The panel shows the high reflectance(30%) and contrast ratio(20:1) resulted from optimizing the optical films and designing the embossing shaped reflector. By improving the chromacity, the color reproducibility was increased up to 20%. As removing the backlight unit, we reduced the power consumption, thickness and weight of the panel to 0.8W, 2.2mm, and 250gram, respectively. According to the above performances, we have obtained fabrication process for mass production, and furthermore, could have access to fast market launching.