• Title/Summary/Keyword: Schiff base

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Electrochemical Properties of Cobalt(II) Schiff Base Complexes in Nonaqueous Solvent (비수용매에서 Schiff Base를 가진 Cobalt(II) 착물들의 전기화학적 성질)

  • Oh, Jeong-Geun;Choi, Yong-Kook
    • Analytical Science and Technology
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    • v.15 no.2
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    • pp.97-101
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    • 2002
  • Co(II) complexes with tridentate Schiff base-NOIPH and tetradentate Schiff base-$NOTDH_2$ and $TNBPH_4$ were synthesized. The redox process of the complexes in DMF solution containing 0.1M TBAP was investigated at glassy carbon electrode by cyclic voltammetry and differential pulse voltammetry techniques. Reduction step of [Co(II)$(NOIP)_2$] and [Co(II)$(H_2O)_2$] complexes were observed in two step as one electron process of irreversible or quasi-reversible and diffusion-controlled reaction. [$Co(II)_2$(TNBP)] complex was observed in one step as one electron process of quasi-reversible and diffusion-controlled reaction.

Electrochemical Properties of Copper(II) Complexes with Multidentate N,O-Schiff Base Ligands (여러 자리 산소-질소계 시프염기 리간드 구리(II) 착물의 전기화학적 특성)

  • Kim, Sun-Deuk;Jang, Gi-Ho;Kim, Jun-Kwang;Lee, Seong-Woo;Joung, Jae-Joung
    • Analytical Science and Technology
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    • v.9 no.4
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    • pp.345-354
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    • 1996
  • Algal(II) Multidentate N, O-Schiff base ligands, such as bis(salicylaldehyde) ethylenediimine(SED), bis(salicylaldehyde) propylenediimine(SPD), bis(salicylaldehyde) diethylenetriimine(SDT), bis (salicylaldehyde) triethylenetetraimine(STT) and bis(salicyl-aldehyde)tetraethylenepentaimine(STP) were prepared. Stepwise proton dissociation constants of the Schiff base were measured potentiometrically in ethanol and a mixture of 70% dioxane and 30% $H_2O$. The stability constants of copper(II)-Schiff base complexes were in the order of Cu(II)-SPD${\leq}$Cu(II)-SED~STT${\leq}$Cu(II)-STP. Oxidation-reduction process of the Cu(II)-Schiff base complexes was involved with one-electron reaction.

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Syntheses and Properties of Polydentate Schiff Base and Their Cu(Ⅱ) Complexes (여러자리 시프 염기 리간드와 구리(Ⅱ) 착물의 합성과 성질)

  • Kim, Seon Deok;Sin, Yun Yeol;Jang, Gi Ho
    • Journal of the Korean Chemical Society
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    • v.38 no.4
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    • pp.319-327
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    • 1994
  • The novel Schiff base hexadentate ligand, bis-(salicylaldehyde)-triethylentetramine (BSTT) and heptadentate ligand, bis-(salicylaldehyde)-tetraethylenpentamine(BSTP) were synthesized by the reaction of salicylaldehydes with triethylenetetramine and tetraethylenepentamine, having four and five nitrogen atoms, respectively. These liquid Schiff base ligands were become in form of the pale-yellow crystals in the specific pH 4.0 by adding acetic acid concentrated hydrochloric acid. The Cu(Ⅱ) complexes of the Schiff bases were synthesized by reaction of the Schiff base with Cu(Ⅱ) ion and their possible structures were proposed by several analytical data, and physical and chemical properties.

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Selective Oxidation of 2,6-di-tert-butylphenol and Electrochemical Properties by Oxygen Adducted Tetradentate Schiff Base Cobalt (Ⅲ) Activated Catalysts in Aprotic Solvents (비수용매에서 산소 첨가된 네자리 Schiff Base Cobalt(Ⅲ) 활성 촉매들에 의한 2,6-di-tert-butylphenol의 선택 산화와 전기화학적 성질)

  • Jo, Gi Hyeong;Choe, Yong Guk;Ham, Hui Seok;Kim, Sang Bok;Seo, Seong Seop
    • Journal of the Korean Chemical Society
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    • v.34 no.6
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    • pp.569-581
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    • 1990
  • It is generated in DMF by activated catalysts of superoxo cobalt(III) complex, such as [Co(III)(Schiff base)(L)]O$_2$ (Schiff base; SED, SOPD and o-BSDT, L; DMF and Py) which mole ratio of oxygen to metal is 1:1 that oxidation major product of 2,6-di-tert-butylphenol by homogeneous oxidatve catalysts of oxygen adducted tetradentate Schiff base cobalt(III) is 2,6-ditert-butylbenzoquinone (BQ). And oxidation product of 3,3',5,5'-tetra-tert-butyldiphenoquinone (DPQ) is generated by activated catalysts such as $\mu$-peroxo cobalt(III) complex; $[Co(III)(SND)(L)]_2$$O_2$ (L; DMF and Py) which mole ratio of oxygen to metal is 1:2. It is difficult to identify these homogeneous activated catalysts such as superoxo and $\mu$-peroxo cobalt(III) complexes in DMF and DMSO solvents. But we can identify by P.V.T method of the oxygen absorption in pyridine solvent and by the reduction process occurred to four steps including prewave of O$_2$- in 1:1 oxygen adducted superoxo cobalt(III) complexes and three steps not including prewave of O$_2$- in 1:2 oxygen adducted $\mu$-peroxo cobalt(III) complexes by the cyclic voltammetry with glassy carbon electrode in 0.1 M TEAP as supporting electrolyte solutidn.

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Electrochemical Properties of Pentadentate Binucleated Schiff Base Cobalt(Ⅱ) and Manganese(Ⅱ) Complexes in Nonaqueous Solvent (비수용매에서 이핵성 다섯자리 Schiff Base Cobalt(Ⅱ) 및 Manganese(Ⅱ) 착물들의 전기화학적 성질)

  • Ki-Hyung Chjo;Yong-Kook Choi;Song-Ju Lee;Seong-Seop Seo
    • Journal of the Korean Chemical Society
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    • v.36 no.3
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    • pp.428-441
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    • 1992
  • We synthesized a series of binuclear pentadentate Schiff base complexes such as $Co(Ⅱ)_2$ (BSPP)($H_2O)_2$, $Co(Ⅱ)_2$ (BSPD)($H_2O)_2$, $Mn(Ⅱ)_2$ (BSPP)($H_2O)_2$ and $Mn(Ⅱ)_2$ (BSPD)($H_2O)_2$, mononuclear pentadentate Schiff base complexes such as Co(Ⅱ)(BSP)($H_2O)$ and Mn(Ⅱ)(BSP)($H_2O)$. The composition of these complexes identified by IR, UV-visible spectrum, T.G.A., DSC, and elemental analysis. The electrochemical redox processes have been examined by cyclic voltammetry and differential pulse polarography with glassy carbon electrode in 0.1M TEAP-Py(-DMSO and -DMF) as a supporting electrolyte solution. As a result of electrochemical measurements, the reduction processes for pentadentate binuclear Schiff base cobalt(Ⅱ) and manganese(Ⅱ) complexes occurred to four steps in $M(Ⅲ)_2$ / $Mn(Ⅱ)_2$ and $Mn(Ⅱ)_2$ / $M(Ⅰ)_2$ (M; Co, Mn) two processes through each two reduction steps with one electron, by contrast, the mononuclear pentadentate Schiff base cobalt(Ⅱ) and manganese(Ⅱ) complexes occurred to two steps in M(Ⅲ) / M(Ⅱ) and M(Ⅱ) / M(Ⅰ) (M; Co, Mn) two processes with one electron reduction steps.

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Synthesis of Cobalt(II), Nickel(II) and Copper(II) Complexes with Tetradentate Schiff Base Ligand of o-BSDT $H_2$ and Electrochemical properties in DMSO (네자리 Schiff Base 리간드의 Cobalt(II), Nickel(II) 및 Copper(II) 착물의 합성과 DMSO용액에서 전기화학적 성질)

  • Ki-Hyung Chjo;Jong-Soon Kim
    • Journal of the Korean Chemical Society
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    • v.31 no.6
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    • pp.509-519
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    • 1987
  • The tetradentate Schiff base ligand, 3,4-bis(salicylidene diimine) toluene, have been prepared by the reaction of salicylaldehyde with 3,4-diaminotoluene by Duff method. The Schiff base ligand reacts with Ni(II), Co(II), and Cu(II) ions to form new complexes, [Ni(o-BSDT)${\cdot}(H_2O)_2$], [Co(o-BSDT)${\cdot}(H_2O)$], and [Cu(o-BSDT)]. It seems that Ni(II) and Ni(II) complexes are hexacoordinated with the Schiff base ligand and two molecules of water, while the Cu(II) complexes are tetracoordinated with the Schiff base. The mole ratio of tetradentate Schiff base ligand to metals was found to be 1 : 1. The redox chemistry of these complexes was investigated by polarography and cyclic voltammetry with glassy carbon electrode in DMSO with 0.1M TEAP${\cdot}$[Ni(o-BSDT)${\cdot}(H_2O)_2$] hav EC reaction mechanisms which undergo a irreversible electron transfer followed by a fast chemical reaction. [Co(o-BSDT)${\cdot}(H_2O)_2$] undergoes a reduction of Co(II) to Co(I) and a oxidation of Co(II) to Co(III), and [Cu(o-BSDT)] undergoes a reduction of Cu(II) to Cu(I).

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Morphological study of porous aromatic schiff bases as a highly effective carbon dioxide storages

  • Rehab Hammoda;Naser Shaalan;Mohammed H. Al-Mashhadani;Dina S. Ahmed;Rahimi M. Yusop;Ali H. Jawad;Emad Yousif
    • Analytical Science and Technology
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    • v.36 no.5
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    • pp.236-249
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    • 2023
  • Carbon dioxide (CO2) capture and storage is a critical issue for mitigating climate change. Porous aromatic Schiff base complexes have emerged as a promising class of materials for CO2 capture due to their high surface area, porosity, and stability. In this study, we investigate the potential of Schiff base complexes as an effective media for CO2 storage. We review the synthesis and characterization of porous aromatic Schiff bases materials complexes and examine their CO2 sorption properties. We find that Schiff base complexes exhibit high CO2 adsorption capacity and selectivity, making them a promising candidate for use in carbon capture applications. Moreover, we investigate the effect of various parameters such as temperature, and pressure on the CO2 adsorption properties of Schiff base complexes. The Schiff bases possessed tiny Brunauer-Emmett-Teller surface areas (4.7-19.4 m2/g), typical pore diameters of 12.8-29.43 nm, and pore volumes ranging from 0.02-0.073 cm3/g. Overall, our results suggest that synthesized complexes have great potential as an effective media for CO2 storage, which could significantly reduce greenhouse gas emissions and contribute to mitigating climate change. The study provides valuable insights into the design of novel materials for CO2 capture and storage, which is a critical area of research for achieving a sustainable future.

Stability Constants for Co(II) and Zn(II) of Multidentate N,O-Schiff Base Ligands in Dioxane-Water Mixtures (물-디옥산 혼합용매에서 여러자리 산소-질소계 Schiff 염기리간드와 코발트(II) 및 아연(II)이온의 착물 안정도상수)

  • Kim, Sun-Deuk;Kim, Jun-Kwang;Lee, Sung-Woo
    • Analytical Science and Technology
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    • v.11 no.2
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    • pp.145-149
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    • 1998
  • Stability constants for the complexes of multidentate N,O-Schiff base ligands (bis-(salicylaldehyde)ethylendiamine(SED), bis-(salicylaldehyde)propylendiamine(SPD), bis-(salicylaldehyde)diethylenetriamine(SDT), bis-(salicylaldehyde)triethylenetetraamine(STT), and bis-(salicylaldehyde)tetraethylenepentaamine(STP) with Co(II) and Zn(II) were determined by a potentiometric method in a 70% dioxane-30% water mixture and ethanol, respectively. Stability constants for the complexes increased in the order of SPD

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Synthesis and Characterization of Derivatives of Dibutyl Sn(IV)-Ti(IV)-μ-Oxoisopropoxide with Schiff Bases

  • Kumar, Rajesh;Sharma, H.K.
    • Journal of the Korean Chemical Society
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    • v.56 no.1
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    • pp.54-57
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    • 2012
  • New Schiff base derivatives of organoheterobimetallic-${\mu}$-oxoisopropoxide $[Bu_2SnO_2Ti_2(OPr^i)_6]$ have been synthesized by the thermal condensation ${\mu}$-oxoisopropoxide compound with Schiff bases in different molar ratios (1:1-1:4) yielded the compounds of the type $[Bu_2SnO_2Ti_2(OPr^i)_{6-n}(SB)_n]$ (where n is 1-4 and SB=Schiff base anion) respectively. The ${\mu}$-oxoisopropoxide derivatives have been characterized by elemental, spectral analysis (IR, $^1H$, $^{13}C$, $^{119}Sn$ NMR) and molecular weight measurement The studies reveal that the derivative compounds show monomeric nature. Further these are found less susceptible to hydrolysis as compared to parent compound and may prove excellent precursors for the mixed metal oxides.