• 제목/요약/키워드: Vanadium(IV) complexes

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Metal Cupferrate Complex에 關한 硏究(第4報) Spectrophotometry에 의한 바나듐(IV) 및 바나듐(V)-Cupferrate 의 化學組成의 決定 (Study on Metal Cupferrate Complex (Part IV). Determination of Vanadium(IV) and Vanadium(V) Cupferrate Compositions)

  • 김시중
    • 대한화학회지
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    • 제8권4호
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    • pp.147-152
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    • 1964
  • 有機溶媒(benzene)에 의한 抽出法을 利用하고, 分光光度法에 의한 몰比法과 連續變化法을 써서, V(IV)-cupferrate와 V(V)-cupferrate의 化學沮成이 水溶液相에서 有機溶媒相으로 分配된 다음에도 雙하지 않을 것이라는 假定밑에서, 水溶液의 酸性度에 따르는 cupferrate 錯化合物의 化學組成을 決定하였다. V(IV)-cupferrate의 benzene 溶液에서의 最大吸光波長은 pH에 따라 445$m{\mu}$ 또는 450$m{\mu}$이고, V(V)-cupferrate의 그것은 pH 1.8以下에서는 pH에 無關하게 445$m{\mu}$이었다. V(V)-cupferrate의 化學組成은 沈澱이 形成되는 水溶液의 pH에 따라 다르며, pH 1.0 以下에서는 $VCupf_4$, pH 1.3∼1.7에서는 $HVOCupf_3$ 또는 $VCupf_4$$VOCupf_2$의 거의 같은 몰씩으로된 混合物이고, pH 1.8∼4.3에서는 $VOCupf_2$이었다. V(V)-cupferrate의 化學組成은 水溶液의 pH에 따라 變化가 없고, pH 1.8 以下에서는 $HVO_2Cupf_2$이었다.

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옥심계 금속착물의 합성과 그 물성에 관한 연구 치환 살리실알데히드옥심의 바나듐(Ⅳ) 착물(1) (Synthesis and Characterization of Metal Complex Oxo Vanadium(Ⅳ) Complexes with Derivatives of Salicylaldoximes)

  • 이광;이원식
    • 대한화학회지
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    • 제39권8호
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    • pp.611-616
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    • 1995
  • 살리실알데히드 옥심, o-바닐린 옥심, 2-히드록시-4-메톡시벤즈알데히드 옥심, 2-히드록시-5-메톡시벤즈알데히드 옥심 및 5-니트로벤즈알데히드 옥심의 옥소바나듐(IV)착물들을 합성하고, 착물들의 특성을 원소분석, 전기전도도 측정, 적외선 분광법, 전자 분광법, 질량 분석법, 및 열분석으로 조사하였다. 원소분석의 결과는 이론 값과 실험 값이 일치하였다. 착물들은 DMF 용액에서 비전해질이었다. 바나듐(IV)과 말단 산소사이의 특성 신축진동은 $980{\pm}20\;cm^{-1}$의 영역에서 강하게 나타났다.모든 착물은 가시영역에서 2개의 결정장전이와 적외선 영역에서 2개의 전하이동 전이가 일어났다. 질량분석 결과로서 $VO(sal)_2$$VO(van)_2$에서는 분자량에 해당하는 1:2(금속:리간드) 착물의 이온(I)과 착물의 이온(I)에서 한리간드가 분해한 1:1(금속:리간드) 조성의 토막 이온(II)을 확인할 수 있었다. 시차열분석 결과에 의하면 열분해에 따른 흡열 봉우리가 나타났다.

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Oxovanadium(IV) Complexes Containing VO(ONS) Basic Core: Synthesis, Structure, and Spectroscopic Properties

  • Jang, Yoon-Jung;Lee, Uk;Koo, Bon-Kweon
    • Bulletin of the Korean Chemical Society
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    • 제26권1호
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    • pp.72-76
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    • 2005
  • Some mononuclear oxovanadium(IV) complexes having the general formula [VOL(bidentate)] (1-4) of which L is tridentate ONS-donor salicylaldehyde S-methyldithiocarbazate (sal-mdtc$^{2-}$) or salicylaldehyde 4- phenylthiosemicarbazate (sal-phtsc$^{2-}$) and bidentate stands for 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) have been synthesized. The complexes were characterized by elemental analyses, FAB mass, UV, IR spectroscopy, and cyclic voltammetry. Two of the complexes [VO(sal-mdtc)(bpy)] (1) and [VO(sal-mdtc) (phen)] (2) were crystallographically characterized. The structures revealed that vanadium atom is octahedrally coordinated by the O, N, and S donor atoms of the tridentate ligand, the two N atoms of bidentate ligand, and the oxo atom. The oxygen donor, occupying an apical position has a trans-labilizing effect, resulting in elongation of the V-N bond. The cyclic voltammograms of the complexes exhibited one cathodic response in the range −d1.45 $\sim$ −f1.52 V due to the reduction of V(IV) to V(III).

Detection of Superoxide Anion and Singlet Oxygen in the Decomposition of Several Peroxovanadium(V) Complexes

  • Kanamori, Kan;Hata, Kaori;Shimoyama, Toshiyuki;Hayakawa, Shingo;Tajima, Hirotaka;Matsugo, Seiichi
    • Journal of Photoscience
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    • 제9권2호
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    • pp.412-414
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    • 2002
  • Several peroxovanadium(V) complexes with an organic chelate ligand decompose spontaneously, depending on the nature of the chelate ligand. The self-decomposition reactions of the dinuclear peroxovanadium(V) complex with 2-oxo-l,3-diaminopropane-N,N,N',N'-tetraacetate (dpot) and the peroxovanadium(V) complexes with N-carboxymethylhistidinate (cmhist) and histamine-N,N-diacetate (histada) accompany the reduction of vanadium(V) to vanadium(IV). This implies that the peroxide anion acts as a reducing agent and thus the peroxide is oxidized in the decomposition process of the peroxovanadium(V) complexes. The oxidized dioxygen species have been characterized spectrophotometrically. Superoxide anion has been detected in 2-3 % yields using the reduction of cytochrome c method and chemiluminescence method utilized MCLA as a fluorescer. Singlet oxygen has also been detected in higher yields on the basis of chemiluminescence of tryptophan.

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V(IV) Species, Location and Adsorbate Interactions in VH-SAPO-42 Studied by ESR and Electron Spin-Echo Modulation Spectroscopies

  • Back, Gern-Ho;Yu, Jong-Sung;Lee, Hye-Young;Kim, Min-Sik;Lee, Yong-Ill
    • 한국자기공명학회논문지
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    • 제11권2호
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    • pp.95-109
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    • 2007
  • Vanadium-incorporated aluminophosphate microporous molecular sieve VH-SAPO-42 has been studied by electron spin resonance(ESR) and electron spin-echo modulation (ESEM) spectroscopies to determine the vanadium location and interaction with various adsorbate molecules. The results are interpreted in terms of V(IV) ion location and coordination geometry. Assynthesized VH-SAPO-42 contains only vanadyl species with distorted octahedral or trigonal bipyramidal coordination. Vanadium incorporated into H-SAPO-42 occupied extra-framework site. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. Species A is identified as a $VO(H_2O)_2^{2+}$ complex coordinated to three framework oxygen atoms bonded to aluminum. When hydrated VH-SAPO-42 is dehydrated at elevated temperature by calcination, species A loses its water ligand and transforms to $VO^{2+}$ ions coordinated to three framework oxygens (species B). Species B reduces its intensities significantly after treatment with $O_2$ at high temperature, thus suggesting oxidation of $V^{4+}$ to $V^{5+}$. When dehydrated VH-SAPO-42 makes contact with $D_2O$ at room temperature, the ESR signal of species A is regained. The species is assumed as a $VO(O_f)_3(D_2O)_2$ by considering three framework oxygens. Adsorption of deuterated methanol on dehydrated VH-SAPO-42 results in another new vanadium species D, which is identified as a $VO(CD_3OH)_2$ complex. When deuterated ethylene is adsorbed on dehydrated VH-SAPO-42, another new vanadium species E identified as a $VO(C_2D_4)^{2+}$, is observed. Possible coordination geometries of these various complexes are discussed.

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The V(IV) Species, Locaton and Adsorbate Interaction in VH-SAPO-11 studied by ESR and ESEM

  • Back, Gernh-ho;Back, Seung-Chan;Park, Sung-Gun;Lee, Chul-wee
    • 한국자기공명학회논문지
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    • 제9권1호
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    • pp.1-20
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    • 2005
  • Vanadium-incorporated aluminophophate molecular sieve VH-SAPO-11 has been studied by electron spin resonanace (ESR) and electron spin echo modulation (ESEM) spectroscopies to determine the vanadium locatin and interaction with various adsorbate molecules. As-synthsized VH-SAPO-11 contains only vanady1 species with distored octahral coordination. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. Species A is suggested as a VO$(H_2O)_2^{2+$} complex coordinate to three framwork oxygen bonded to aluminum. When calcined, hydrate VH-SAPO-11 is dehydrated at elevated temperature, species A loses it water ligands and transforms to $VO^{2+}$ ions coordinated to three framework oxygens (species B). Species B reduces its intensities significantly after treatment with $O_2$at high temperature, thus suggesting oxidation of $v^{4+}$to $v^{5+}$. When dehydrated VH-SAPO-11 contacts with $D_2O$ at room temperature, the ESR signal of species A is observed. This species assumed as a $VO(O_f)_3(D_2O)_2$, by considering 3 framework oxygens. Adsorption of deuterated methanol on dehydrated VH-SAPO-11 results in another new vanadium species D, which is identified as a $VO(CD_{3}OH)$ complex. When deuterated ethanol is adsorbed on dehydrated VH-SAPO-11, another new vanadium species E identified as a $VO(C_{2}H_{5}OD)^{2+}$, is observed. When deuterated propanol is adsorbed on dehydrated VH-SAPO-11, a new vanadium species F identified as a $VO(C_{3}H_{7}OD)$, is observed. Possible coordination geometries of these various complexes are discussed.

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The Study on Location and Adsorbate Interaction for Vanadium Species in $VO^{2+}-SAPO-5$ by Electron Spin Resonance and Electron Spin Echo Modulation Spectroscopies

  • Back Gern-Ho;Park Sung-Gun;Lee Chul-Wee
    • 한국자기공명학회논문지
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    • 제9권2호
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    • pp.138-154
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    • 2005
  • Vanadium-incorporated aluminophosphate molecular sieve $VO^{2+}-SAPO-5$ was studied by electron spin resonance (ESR) and electron spin echo modulation (ESEM) spectroscopies to determine the vanadium structure and interaction with various adsorbate molecules. It was found that the main species at low concentration of vanadium is a monomeric vanadium units in square pyramidal or distorted octahedral coordination, both in oxidation state (IV) for the calcined hydrated material and in oxidation state (V) for the calcined material. After calcinations in $O_2$ and exposure to moisture, only species A is observed with reduced intensities. It is suggested as a $VO(H_2O)_3^{2+}$ complex coordinated to two framework oxygen bonded aluminum. When calcined, hydrated $VO^{2+}-}SAPO-5$ is dehydrated at elevated temperature, a species loses its water ligands and transforms to $VO^{2+}$ ions coordinated to two framework oxygens (species B). Species B reduces its intensity, significantly after treatment with $O_2\;at\;600^{\circ}C$ for 5 h, thus suggesting oxidation of $V^{4+}\;to\;V^{5+}$. When dehydrated $VO^{2+}-SAPO-5$ contacts with $D_2O$ at room temperature, the EPR signal of species A is observed. Thus species assumed as a $VO^{2+}(O_f)_2(D_2O)_3$, by considering two framework oxygens. Adsorption of deuterated ethanol, propanol on dehydrated $VO^{2+}_{-}SAPO-5$ result in another new vanadium species E and F, respectively, which are identified as a $VO^{2+}-(CH_3CH_2OD)_3,\;VO^{2+}-(CH_3CH_2CH_2OD)_2$ complex. When deuterated benzene is adsorbed on dehydrated $VO^{2+}-SAPO-5$, another new vanadium species G, identified as a $VO^{2+}-(C_6D_6)$ is observed. Possible coordination geometries of these various complexes are discussed.

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Polarographic Behavior of Oxovanadium (IV) Complex of Mercaptopyridine N-Oxide

  • Shim, Yoon-Bo;Choi, Sung-Nak
    • Bulletin of the Korean Chemical Society
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    • 제8권4호
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    • pp.225-230
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    • 1987
  • The redox properties of 2-mercaptopyridine N-oxide (mpno) and its oxovanadium complex, $VO (mpno)_2$ have been studied by the use of polarography and cyclic voltammetry. The radical anion of mpno is generated in acetone and is adsorbed to the electrode to form an adsorption wave at -0.21 V vs Ag/AgCl electrode. The normal wave appeared at -0.50 V is attributed to the formation of radical anion. The $VO (mpno)_2$ exhibits one oxidation wave at +0.57 V, and two reduction waves at -1.07 V and -1.76 V vs. Ag/AgCl electrode; the oxidation is fully reversible one-electron process ($VO (mpno)_2\;{\leftrightarrow}\;VO(mpno)_2^+ + e).$ The reduction wave at -1.07 V is quasireversible and is arised from the formation of $VO (mpno)_2^-.$ The second reduction wave at -1.76 V is irreversible and this reduction process consists of two one-electron steps. The sulfur containing ligands seem to enhance the stability of lower oxidation state of vanadium while the oxygen or nitrogen donor of the ligands stabilize the higher oxidation state of vanadium when comparisons are made among several oxovanadium complexes.

옥소바나듐 (IV) 과 벤조히드로옥사믹산 간에 형성되는 착물의 전기화학적 성질에 관한 연구 (Electrochemical Behavior of Oxovanadium (IV) Complex of Benzohydroxamic Acid)

  • 추희식;박덕수;심윤보;최성낙
    • 대한화학회지
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    • 제33권3호
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    • pp.281-286
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    • 1989
  • 벤조히드로옥사믹산(Hben)과 이의 옥소바나듐(IV) 착화합물, $VO(Ben)_2$의 전기화학적 거동을 폴라로그래피와 순환 전압 전류법을 이용하여 조사하였다. Hben의 경우, 아세톤 용매중에서 얻은 폴라로그램은 Ag/AgCl 전극에 대해 -0.05V와 -1.78V에서 두개의 환원파를 나타내었다. 첫번째 환원파는 단일 라디칼 음이온의 생성에, 그리고 두번째 환원파는 이중 라디칼 음이온의 생성에 기인하는 것으로 해석되었다. $VO(Ben)_2$ 착물의 폴라로그램은 +0.55V에서 한개의 산화파를, 그리고 -0.15V와 -1.30V에서 각각 한개씩의 환원파를 나타내었다. +0.55V의 전극반응은 1전자 산화과정이었다$(VO(ben)_2 {\rightleftharpoons} VO(ben)^+ + e)$. -0.15V에 나타난 환원파는 준가역적인 역시 1전자 과정이었으며 $VO(Ben)_2^-$라디칼 형성에 의한 것으로 해석되었다. -1.30V에서 나타난 환원파는 비가역적이며 이 과정에서는 바나디움(III)이온을 생성하는 것으로 믿어진다. 산소 주게 원자를 갖는 Hben 리간드는 황이나 질소를 포함하는 다른 리간드들과 비교해 볼 때 중심금속인 바나듐의 +4가 산화상태의 안정성을 감소시키는 것으로 믿어진다.

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