• Title/Summary/Keyword: transition metal complexes

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Decomposition Studies of DFP Using Transition Metal Catalysts (전이금속촉매를 사용한 DFP 분해 성능 연구)

  • Kye, Young-Sik;Jeong, Keunhong;Chung, Woo Young
    • Applied Chemistry for Engineering
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    • v.21 no.1
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    • pp.1-5
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    • 2010
  • Cu(II)-organic complexes were synthesized with Lewis base organic ligands including diamine, aminothiol, and dithiol to determine the reactivity for DFP hydrolysis. Results show that the aminothiol catalyst enhances the hydrolysis of DFP in three folds compared to diamine type because aminothiol has higher basicity than diamine. Due to low solubility of Cu(II)(1,2-ethane dithiol)$(NO_3)_2$, it is impossible to compare directly the rates in homogeneous condition. However, the rate of dithol complex is even 1.6 times faster than that of the diamine type. The reactivity of zeolite for DFP hydrolysis is also evaluated. NaY type does not promote the hydrolysis, but RuNaY shows relatively lower reactivity than those of Cu(II)-organic ligands complexes.

The Electronic Structure and Reactivity of Transition Metal Complexes (II). Molecular Orbital Studies of the Series $[M(NH_3)_5Cl]^{2+}$ (M = Cr, Co, Ru, Rh, Os, Ir) by the Relativistically Parameterized Extended Huckel Method (전이금속 착물의 전자구조 및 화학적 반응성 (제 2 보). 상대론적으로 파라미터화된 확장 Huckel 법에 의한 $[M(NH_3)_5Cl]^{2+}$ (M = Cr, Co, Ru, Rh, Os, Ir) 계열의 분자궤도함수론적 연구)

  • Jong-Jae Chung;Hwan-Jin Yeo;Jong-Ha Choi;Iee-Yeung Cho
    • Journal of the Korean Chemical Society
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    • v.33 no.6
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    • pp.571-576
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    • 1989
  • The relativistically parameterized Extended Huckel (REX) calculations are carried out for $[M(NH_3)_5Cl]^{2+}$ (M = Cr, Co, Ru, Rh, Os, Ir). The calculated orbital and overlap populations agree with experimental data. The REX calculations on the electronic structure have been also compared with nonrelativistic EHT results. A ${\phi}$-bonding in M-Cl bond is founded to be more important for the $d^3$, $d^5$complexes than the $d^6$ system.

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Potentiometric Study of Transition Metal Ions Complexes of Hexadentate($N_4$, $O_2$) Ligands (질소-산소계 여섯 자리 리간드들의 전이금속이온 착물에 대한 전위차법 연구)

  • Kim, Sun-Deuk;Kim, Jun-Kwang;Lee, Woo-Sik
    • Journal of the Korean Chemical Society
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    • v.44 no.6
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    • pp.518-525
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    • 2000
  • The open-chain hexadentate N$_4$, O$_2$ ligands 1,13-bis(2-hydroxybenzyl)-2,5,9,12-tetraazatridecane-tetrahydrochloride (BSATD${\cdot}$4HCl) and 1,14-bis (2-hydroxybenzyl)-2,6,9,12-tetraazatetradecane-tetrahydrochloride (BSATED${\cdot}$ 4HCl) have been synthesized as their tetrahydrochloride salt and characterized by EA, IR, NMR and Mass. Their proton dissociation constants(log$K^{n}_{H}$) and stability constants(log$K_{ML}$) for Cu(II), Ni(II), Co(II), and Zn(II) ions were determined in aqueous solution by potentiometry and compared with those of analogous N$_4$, O$_2$ ligands contain ethylenic spacers or propylenic spacers, which make six-membered chelate rings between the aliphatic nitrogen atoms. Synthesis and characterization of [Cu(BSATD)]ClO$_4$ and [Cu(BSATED)](ClO$_4$)$_2$ complexes are described.

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Calculation of the Magnetic Moments for Transition Metal Complexes (Ⅱ). The Magnetic Moments for Distorted Octahedral $[V(III)A_3B_3]$ Type Complexes and the Contribution of $^3T_1$ Term to the Dipole Moments and Polarizability [A and B = O, Cl, N or Br] (전이원소착물의 자기모멘트의 계산 (제2보). $t^2_2$ 전자구조를 갖는 일그러진 판면체 $[V(III)A_3B_3]$형태 착물의 자기모멘트와 쌍극자모멘트 및 편극율에 대한 $^3T_1$항의 기여분 [A 와 B = O, Cl, N 또는 Br])

  • Sangwoon Ahn;Se Woung Oh;Kee Hag Lee;Eu Suh Park
    • Journal of the Korean Chemical Society
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    • v.24 no.4
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    • pp.269-279
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    • 1980
  • A method for calulation of the magnetic moments for both octahedral and distorted octahedral $[V(III)A_3B_3]$ type complexes, all with $t^2_2$ configuration, has been developed [A and B = O, Cl, N, F or Br]. The calculated magnetic moments by this method are in reasonable agreements with the experimental values. The calculated magnetic moments for distorted octahedral $[V(III)A_3B_3]$/TEX> type complexes decrease as the extent of tetragonal distortion increases.The effects of k (orbital reduction faction factor), $\xi'$/TEX> and temperature on the magnetic moments are also investigated.A new method for calculation of the contribution of $^3T_1$ molecular orbitals to the dipole moment and polarizability has also developed. The calculated contribution of $^3T_1$ molecular orbitals falls in the reasonable range of values.

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Spectroscopic, Thermal and Biological Studies on Newly Synthesized Cu(II), Ni(II) and Co(II) Complexes with 3-N-2-hydroxyethylamine Benzanthrone and 3-N-2-aminoethylamine Benzanthrone (3-N-2-hydroxyethylamine benzanthrone 및 3-N-2-aminoethylamine benzanthrone에 대한 Cu(II), Ni(II) 및 Co(II) 착물의 분광학, 열 및 생물학적 연구)

  • Refat, Moamen S.;Megahed, Adel S.;El-Deen, Ibrahim M.;Grabchev, Ivo;El-Ghol, Samir
    • Journal of the Korean Chemical Society
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    • v.55 no.1
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    • pp.28-37
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    • 2011
  • Spectroscopic (infrared, electronic and $1^H$-NMR), elemental analyses CHN, molar conductivity, thermogravimetric analyses (TGA/DTG) and biological studies, of both benzanthrone derivatives 3-N-2-hydroxy ethylamine benzanthrone (HEAB) and 3-N-2-amino ethylamine benzanthrone (AEAB) with Cu(II), Co(II) and Ni(II) chlorides were discussed herein. Based on the above studies, HEAB ligand was suggested to be coordinated to each metal ions via hydroxo and amino groups to form [Cu(HEAB)$(Cl)_2$].$2H_2O$, [Co(HEAB)$(Cl)_2(H_2O)_2$].$8H_2O$ and [Ni(HEAB)$(Cl)_2(H_2O)_2$].$7H_2O$ coordinated complex. On the other hand, AEAB has an octahedral coordinated feature with formulas [Cu(AEAB)$(Cl)_2(H_2O)_2$].$2H_2O$, [Co(AEAB)$(Cl)_2(H_2O)_2$].$4H_2O$ and [Ni(AEAB)$(Cl)_2(H_2O)_2$]. $6H_2O$. The molar conductance values at $25{\circ}C$ for all complexes in DMF are slightly higher than free ligands; this supported the presence of chloride ions inside the coordination sphere. Both benzanthrone ligands and their complexes have been screened against different kinds of bacteria.

Electronic Structure and Chemical Reactivity of Transition Metal Complexes (Part 16). A Spectroscopic Study on the Electronic Structure of cis-[Cr(cyclam)$Cl_2$]Cl (전이금속 착물의 전자 구조 및 화학적 반응성 (제 16 보). cis-[Cr(cyclam)$Cl_2$]Cl의 전자 구조에 관한 분광학적 연구)

  • Choi, Jong-Ha
    • Journal of the Korean Chemical Society
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    • v.39 no.7
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    • pp.501-507
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    • 1995
  • The electronic structure of cis-$[Cr(cyclam)Cl_2]Cl$ has been investigated by the emission and excitation spectroscopy at 77K, and infrared and visible spectroscopy at room temperature. The ten electronic transitions due to spin-allowed and spin-forbidden are assigned. The zero-phonon line in the excitation spectrum splits into two components by $139\;cm^{-1}$, and it can be reproduced by modern ligand field theory. According to the results of ligand field analysis, we can confirm that nitrogen atoms of the cyclam ligand have a strong ${\sigma}$-donor character, but chloride ligand has weak ${\sigma}-$ and ${\pi}-$donor properties toward chromium(III) ion.

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The Electronic Structure and Reactivity of Transition Metal Complexes (III). Effect of Pressure on the Aquation of $[Cr(NH_3)_5(DMF)]^{3+}$ Ion (전이금속 착물의 전자구조 및 화학적 반응성 (제 3 보) $[Cr(NH_3)_5(DMF)]^{3+}$ 이온의 수화반응에 미치는 압력효과)

  • Jong-Jae Chung;Choi Jong-Ha;Eun-Ki Kim
    • Journal of the Korean Chemical Society
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    • v.33 no.6
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    • pp.582-587
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    • 1989
  • Rates for aquation of $[Cr(NH_3)_5(DMF)]^{3+}$ ion in aqueous acidic solution have been measured by spectrophotometric method at various temperatures and pressures. The volume of activation for the aquation is small negative and lies in the limited range -2.76 ∼ -3.65 $cm^3mol^{-1}$. The entropy and compressibility coefficient of activation are small negative values. From the results of thermodynamic activation parameters, it can be inferred that the aquation of $[Cr(NH_3)_5(DMF)]^{3+}$ ion proceeds through an associative interchange($I_a$) mechanism.

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Transition Metal Catalyzed the Double Hydrohydroxymethylation of Carbonyl Compounds by a Carbon Monoxide-Water System (전이금속촉매-일산화탄소-물계에 의한 카르보닐화합물의 이중 히드로히드록시메틸화 반응)

  • Sang Chul Shim;Kyung Eun Min;Keun Tae Huh
    • Journal of the Korean Chemical Society
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    • v.30 no.1
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    • pp.101-104
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    • 1986
  • Dialdehydes such as adipaldehyde, glutaraldehyde, and succinaldehyde were readily reduced to give their corresponding 1,6-hexanediol, 1,5-pentanediol, and 1,4-butanediol in good yields in the presence of catalytic amount of hexarhodium hexadecacarbonyl or iron pentacarbonyl in water and methoxyethanol or ethanol at 180$^{\circ}C$ for 4 hr under carbon monoxide atmosphere. Under the same reaction conditions, diketones such as 2,5-hexanedione, 2,4-pentanedione, and 2,3-butanedione afforded their corresponding 2,5-hexanediol, 2,4-pentanediol and 2,3-butanediol in moderate yields. For double hydrohydroxymethylation of dialdehydes or diketones, rhodium or iron carbonyl complexes are more effective than others. Particularly, benzoquinone gave hydroquinone quantitatively.

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Spectrophotometric Study of Acidity and Complex Formation of Anti-Inflammatory Drug Piroxicam with Some Transition Metal Ions in Different Methanol/Water Mixtures by Chemometric Methods (Chemometric 방법에 의한 메탄올/물 계에서 전이 금속 이온과 소염제 Piroxicam의 산성도 및 착체 형성에 관한 분광광도법 연구)

  • Ghasemi, Jahan B.;Jalalvand, Alireza
    • Journal of the Korean Chemical Society
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    • v.53 no.6
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    • pp.693-703
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    • 2009
  • The complex formation of anti-inflamatory drug piroxicam (PX, 4-hydroxy-2-methyl-N-2--pridyl-2H-1,2-benzothiazine-3-carboxadiamide-1,1-dioxide) with transition metal ions Co(II), Ni(II), Cu(II) and Zn(II) in methanol(MeOH)/water binary mixtures were studied by spectrophotometric method at 25$^{\circ}C$, constant pH = 5.0 and I = 0.1 M. The computer program SQUAD was used to extract the desired information from the spectral data. The outputs of the fitting processes were stability constants, standard deviations of the estimated stability constants, concentration distribution diagrams and spectral profiles of all species. The sequence of the stability constants of PX complexes with Co(II), Ni(II), Cu(II) and Zn(II) follow the Cu(II) > Co(II) > Ni(II) ${\approx}$ Zn(II) order. This may be due to different geometry tendencies of these metal ions. The acidity constants of the PX were also determined under above condition from its absorption spectra at different pH values. The computer program DATAN was used for determination of acidity constants of PX. The validity of the obtained acidity constants was checked by a well known computer program SPECFIT/32. The effects of the different parameters like solvent nature, cations characteristics on the stability and acidity constants were thoroughly discussed.

New Transition Metal Mediated Alkylation Reaction of arachno-$S_{2}B_{7}H_{8}$, Insertion Reaction of arachno-$S_{2}B_{7}H_{8}^{-}$ with $(CO)_{5}M$ {${C(R_{1})(R_{2})}$} $(M=Cr,\;W;\;R_{1}=CH_{3},\;C_{6}H_{5};\;R_{2}=OCH_{3},\;SC_{6}H{5})$: Synthesis and Characterization of arachno-$4-RCH_{2}-6,8-S_{2}B_{7}H_{8}\;(R=CH_{3},\;IIa;\;C_{6}H_{5},\;IIb)$

  • Hee-Joo Jeon;Jae-Jung Ko;Kang-bong Lee;Sang Ook Kang
    • Bulletin of the Korean Chemical Society
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    • v.14 no.1
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    • pp.113-117
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    • 1993
  • Good yield synthetic routes for the production of new B-alkyl-dithiaborane clusters are reported. The syntheses of the B-alkyl-dithiaboranes are based on the use of Fischer-type carbene reagents to activate the B-H bonds of dithiaborane for alkyl-addition reactions and are the first examples of transition-mediated reactions of dithiaborane to be reported. Thus, reactions employing arachno-$S_2B_7H_8$- and $(CO)_5M{C(R_1)R_2}$ (M = Cr, W; $R_1 = CH_3,\;C_6H_5;\; R_2 = OCH_3,\;SC_6H_5)$ were found to yield the intermidiate anions I, $[(CO)_5M{C(R_1)R_2S_2B_7H_8}]^-$, which upon protonation gave the corresponding neutral, air-sensitive cluster arachno-4-$RCH_2-6,8-S_2B_7H_8(R=CH_3,\;IIa;\;C_6H_5,\;IIb)$ range from 30 to 35% yield. Complexes IIa and IIb are isoelectronic with arachno-6,8-$S_2B_7H_9$ and, on the basis of the spectroscopic data, are proposed to adopt a similar arachno cage geometry in which an $RCH_2$ units are substituted to 4 position boron atom of the arachno-6,8-$S_2B_7H_9$.