• 제목/요약/키워드: Metal coordination

검색결과 176건 처리시간 0.03초

Reactivity of RhCp* Complexes Containing Labile Ligands toward Potential Linking Ligands Containing Terminal Thiophene or Furan Rings:Preparation and Structures of [Cp*Rh(L1)Cl2], [Cp*Rh(η2-NO3)(L1)](OTf),and {[Rh(L2)] · (OTf)}[L1 = 1,2-Bis((thiophen-2-yl)methylene)hydrazine); L2 = 1,2-Bis((furan-2-yl)methylene)hydrazine]

  • Lee, Kyung-Eun;Lee, Soon-W.
    • Bulletin of the Korean Chemical Society
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    • 제31권12호
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    • pp.3600-3604
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    • 2010
  • Rhodium(III)-$Cp^*$ complexes containing labile ligands, $[Cp^*RhCl_2]_2$, [$Cp^*Rh({\eta}^2-NO_3)$(OTf)], and $[Cp^*Rh(OH_2)_3](OTf)_2$, reacted with potential linking ligands [$L^1$ = (2-thiophene)-CH=N-N=CH-(2-thiophene); $L^2$ = (2-furan)-CH=N-N=CH-(2-furan)] to give two molecular compounds, [$Cp^*Rh(L^1)Cl_2$] (1) and [$Cp^*Rh({\eta}^2-NO_3)(L^1)$]$(OTf){\cdot}CH_2Cl_2$ ($2{\cdot}CH_2Cl_2$), and one 1-dimensioanl coordination polymer, $\{[Rh(L^2)]{\cdot}(OTf)}_{\infty}$ (3). Whereas one imine nitrogen atom within the ligand is coordinated to the Rh metal in compounds 1 and 2, both nitrogen atoms are bound to two neighboring Rh metals in compound 3 to lead to a 1-D chain polymer.

Synthesis and Characterization of Various Di-N-Functionalized Tetraaza Macrocyclic Copper(II) Complexes

  • Kang, Shin-Geol;Kim, Na-Hee;Lee, Rae-Eun;Jeong, Jong-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제28권10호
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    • pp.1781-1786
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    • 2007
  • Two copper(II) complexes, [CuL3](ClO4)2 bearing one N-CH2CH2CONH2 group as well as one N-CH2CH2CN group and [CuL4](ClO4)2 bearing two N-CH2CH2CONH2 groups, have been prepared by the selective hydrolysis of [CuL2](ClO4)2 (L2 = C-meso-1,8-bis(cyanoethyl)-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). The complex [CuL5](ClO4)2 bearing one N-CH2CH2C(=NH)OCH3 and one N-CH2CH2CN groups has been prepared as the major product from the reaction of [CuL2](ClO4)2 with methanol in the presence of triethylamine. In acidic aqueous solution, the N-CH2CH2C(=NH)OCH3 group of [CuL5](ClO4)2 undergoes hydrolysis to yield [CuL6](ClO4)2 bearing both N-CH2CH2COOCH3 and N-CH2CH2CN groups. The crystal structure of [CuL5](ClO4)2 shows that the complex has a slightly distorted square-pyramidal coordination polyhedron with an apical Cu-N (N-CH2CH2C(=NH)OCH3 group) bond. The apical Cu-N bond distance (2.269(3) A) is ca. 0.06 A longer than the apical Cu-O (N-CH2CH2CONH2 group) bond of [CuL4](ClO4)2. The pendant amide group of [CuL3](ClO4)2 is involved in coordination. The carboxylic ester group of [CuL6](ClO4)2 is also coordinated to the metal ion in various solvents but is removed from the coordination sphere in the solid state.

Synthesis, Characterization and Biological Activities of 4-(p-Chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide and Its Metal Complexes

  • Hassanien, Mohammad M.;Mortada, Wael I.;Hassan, Ali M.;El-Asmy, Ahmed A.
    • 대한화학회지
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    • 제56권6호
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    • pp.679-691
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    • 2012
  • New series of metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Pt(II) with 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) have been synthesized and characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, $^1H$ NMR, mass and ESR) and thermal studies. The IR data suggest different coordination modes for HCPTS which behaves as a monobasic bidentate with all metal ions except Cu(II) and Zn(II) which acts as a monobasic tridentate. Based on the electronic and magnetic studies, Co(II), Cu(II), Pd(II) and Pt(II) complexes have square - planner, Ni(II) has mixed stereochemistry (tetrahedral + square planar), while Zn(II) is tetrahedral. Molar conductance in DMF solution indicates the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complex show $g_{\parallel}$ (2.2221) > $g_{\perp}$ (2.0899) > 2.0023 indicating square-planar structure and the presence of the unpaired electron in the $d_x2_{-y}2$ orbital with significant covalent bond character. The thermal stability and degradation kinetics of the ligand and its metal complexes were studied by TGA and DTA and the kinetic parameters were calculated using Coats-Redfern and Horowitz-Metzger methods. The complexes have more antibacterial activity against some bacteria than the free ligand. However, the ligand has high anticancer activities against HCT116 (human colon carcinoma cell line) and HEPG2 (human liver hepatocellular carcinoma cell line) compared with its complexes.

황에 저항성을 가지는 수성가스 전환반응 촉매의 연구 II. CoMo 촉매의 활성에 미치는 알칼리 금속염의 영향 (A Study on the Sulfur-Resistant Catalysts for Water Gas Shift Reaction II. Effect of Alkali Metal Salt on the Activity of CoMo Catalyst)

  • 김준희;이호인
    • 대한화학회지
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    • 제42권6호
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    • pp.696-702
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    • 1998
  • 황피독에 저항성을 가지는 수성가스 전환반응용 CoMo 계열 촉매에 알칼리금속염 첨가가 반응활성에 미치는 영향에 대하여 연구하였다. 알칼리금속염의 음이온과 양이온의 각각에 대한 영향을 알아보기 위하여 크게 두 경우로 나누어 촉매를 제조하였다. 그 하나는, 양이온을 K로 고정시키고 음이온을 변형시킨 경우로서, 반응활성의 변화는 BET 표면적의 변화로 설명되었다. 다른 한 경우는, 음이온을 $NO_3^-$로 고정시키고 알칼리금속 이온을 변형시킨 경우로서, Li가 첨가된 촉매의 활성이 가장 뛰어났으며 다른 양이온의 경우에는 서로 비슷한 낮은 활성을 보였다. 알칼리금속의 첨가량의 변화에 따른 BET 표면적의 변화와 반응활성의 변화가 같은 경향을 보였다. 알칼리금속염의 양이온을 변화시킨 경우에는 BET 표면적과 정8면체 배위구조 속의 $Mo^{6+}$에 대한 정4면체 배위구조 속의 $Mo^{6+}$의 비, 즉 $Mo^6+[T]/Mo^{6+}[O]$ 값의 복합적인 관계를 통해 반응활성의 변화를 설명할 수 있었다.

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악틴 및 란탄족금속의 거대고리 착물 (제 1 보). 거대고리 리간드의 금속착물의 형성과 성질 (Macrocyclic Complexes of Actinide and Lanthanide Metals (Ⅰ). Formation and Properties of Cation Complexes with Macrocyclic Ligands)

  • 정오진;최칠남;윤석진;손연수
    • 대한화학회지
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    • 제34권2호
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    • pp.143-158
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    • 1990
  • 본 연구에서는 동공의 크기가 다른 5종의 crown ether과 9종의 crownand계와 1종의 cryptand계 거대고리 리간드를 포함하는 우라늄(Ⅵ), 토륨(Ⅳ) 및 네오디뮴(Ⅲ), 사마륨(Ⅲ), 홀뮴(Ⅲ) 등의 희토류 금속착물을 합성 후, 고체착물의 조성식을 결정하고 적외선 스펙트럼에 의하여 구조를 확인한 다음 핵자기공명 분광법에 의하여 착물용액의 조성비와 분자내의 착물형성 site를 결정하고 착물들의 용매화 현상과 리간드 교환반응성을 핵자기공명 분광법으로 고찰하였다. crown ether 거대고리 리간드들은 실험에 사용한 모든 금속이온과 안정한 착물을 형성하므로 OCH2 메틸렌 양성자들은 모두 낮은 자기장 방향으로 화학적 이동을 나타냈으며 같은 금속이온에 대한 화학적 이동값은 12C4<15C5<18C6의 순으로 증가하였고 같은 리간드에 대한 희토류 착물의 화학적 이동값은 원자번호 크기에 반비례하였다. crownand 22는 우라늄(Ⅵ)과 산소 및 질소원자를 배위하는 안정한 착물을 형성하지만 희토류 금속과는 착물을 형성하지 않았다. 반면에 희토류 금속(Ⅲ)이온은 cryptand 221리간드와 모든 산소 및 질소원자를 배위자로 하는 안정한 착물을 형성할 수 있었다. 나머지 질소와 산소원자를 포함한 crownand 계열 거대고리 리간드는 우라늄(Ⅵ)과 역시 모든 산소 및 질소가 배위하는 착물을 형성하지만 희토류 금속(Ⅲ)과는 착물을 형성하지 않음을 확인할 수 가 있었다. 우라늄(Ⅵ)과 희토류(Ⅲ)금속이온은 모든 거대고리 리간드와 1:1착물을 각각 형성하며 토륨(Ⅳ)이온은 12C4와 1:2 나머지 리간드와는 1:1착물을 각각 형성함을 알 수 있었다. 이들 거대고리 리간드 착물들의 안정성은 착물의 양성자 이동결과에 잘 일치하였다. 그리고 18C6와 물을 리간드로 하는 희토류 금속(Ⅲ) 착물은 아세틸아세톤 용매내에서 리간드 교환반응이 일어나지만 우라늄(Ⅵ)착물의 경우에는 교환반응이 일어나지 않았다.

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Alkali Metal Ion Catalysis in Nucleophilic Substitution Reactions of 5-Nitro-8-quinolyl Benzoate with Alkali Metal Ethoxides in Anhydrous Ethanol: Unusually High Na+ Ion Selectivity

  • Um, Ik-Hwan;Lee, Seung-Eun;Hong, Yeon-Ju;Park, Jee-Eun
    • Bulletin of the Korean Chemical Society
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    • 제29권1호
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    • pp.117-121
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    • 2008
  • Pseudo-first-order rate constants (kobsd) have been measured spectrophotometrically for nucleophilic substitution reactions of 5-nitro-8-quinolyl benzoate (5) with alkali metal ethoxides, EtO?M+ (M+ = Li+, Na+ and K+) in anhydrous ethanol (EtOH) at 25.0 0.1 C. The plots of kobsd vs. [EtO?M+] exhibit upward curvatures, while the corresponding plots for the reactions of 5 with EtO?Na+ and EtO?K+ in the presence of complexing agents, 15-crown-5-ether and 18-crown-6-ether are linear with rate retardation. The reactions of 5 with EtO?Na+ and EtO?Li+ result in significant rate enhancements on additions of Na+ClO4, indicating that the M+ ions behave as a catalyst. The dissociated EtO and ion-paired EtOM+ have been proposed to react with 5. The second-order rate constants for the reactions with EtO (kEtO) and EtOM+ (kEtOM+) have been calculated from ion-pairing treatments. The kEtO and kEtOM+ values decrease in the order kEtONa+ > kEtOK+ > kEtOLi+ > kEtO, indicating that ion-paired EtOM+ species are more reactive than the dissociated EtO ion, and Na+ ion exhibits the largest catalytic effect. The M+ ions in this study form stronger complex with the transition state than with the ground state. Coordination of the M+ ions with the O and N atoms in the leaving group of 5 has been suggested to be responsible for the catalytic effect shown by the alkali metal ions in this study.

Two 3D CdII and ZnII Complexes Based on Flexible Dicarboxylate Ligand and Nitrogen-containing Pillar: Synthesis, Structure, and Luminescent Properties

  • Liu, Liu;Fan, Yan-Hua;Wu, Lan-Zhi;Zhang, Huai-Min;Yang, Li-Rong
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3749-3754
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    • 2013
  • Two 3D isomorphous and isostructural complexes, namely, $[Zn(BDOA)(bpy)(H_2O)_2]_n$ (1) and $[Cd(BDOA)-(bpy)(H_2O)_2]_n$ (2); (BDOA = Benzene-1,4-dioxyacetic acid, bpy = 4,4'-bipyridine) were synthesized under hydrothermal conditions and characterized by means of elemental analyses, thermogravimetric (TG), infrared spectrometry, and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the triclinic system, space group P-1 and each metal ion in the complexes are six-coordinated with the same coordination environment. In the as-synthesized complexes, $BDOA^{2-}$ anions link central metal ions to form a 1D zigzag chain $[-BDOA^{2-}-Zn(Cd)-BDOA^{2-}-Zn(Cd)-]_{\infty}$, whereas bpy pillars connect metal ions to generate a 1D linear chain $[-bpy-Zn(Cd)-bpy-Zn(Cd)-]_{\infty}$. Both infinite chains are interweaved into 2D grid-like layers which are further constructed into a 3D open framework, where hydrogen bonds play as the bridges between the adjacent 2D layers. Luminescent properties of complex 1 showed selectivity for $Hg^{2+}$ ion.

Synthesis and Characterization of New Polyaza Macrocyclic Nickel(Ⅱ) and Copper(Ⅱ) Complexes Two Nitrile or Imidate Ester Pendant Arms: Metal-Mediated Hydrolysis and Alcoholysis of the Nitrile Groups

  • Kang, Shin-Geol;Song, Jeong-Hoon;Jeong, Jong-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제23권6호
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    • pp.824-829
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    • 2002
  • New di-N-cyanomethylated tetraaza macrocycle 2.13-bis(cyanomethyl)-5.16-dimethyl-2,6,13,17-tetraazatricyclo[$16.4.0.0^7.12$]docosane $(L^2)$ has been prepared by the reaction of 3, 14-dimethyl-2,6,13,17-tetraazatricyclo $(L^1)$ with bromoacetonitrile. The square-planar complexes $[ML^2](ClO_4)_2(M=Ni(II)$ or Cu(II) can be prepared by the reaction of $L^2$ with the corresponding metal ion in acetonitrile. The cyanomethyl groups of $[ML^2](ClO_4)_2readily$ react with water to $yield[ML^3](ClO_4)_2$ containing pendant amide groups. The trans-octahedral complexes $[ML^4](ClO_4)_2$, in which two imidate ester groups are coordinated to the metal ion, can be also prepared by the reaction of $[ML^2](ClO_4)_2with$ methanol under mild conditions. The hydrolysis and alcoholysis reactions of $[ML^2](ClO_4)_2are$ promoted by the central metal ion, in spite of the fact that the cyanomethyl group is not involved in intramolecular coordination. The reactions are also promoted by a base such as triethylamine but are retarded by an $acid(HClO_4).Interestingly$, the imidate ester groups of $[ML^4]^2$ are unusually resistant to hydrolysis even in 0.1 M $HCIO_4$ or 0.1 M NaOH aqueous solution. Crystal structure of $[NiL^4](ClO_4)_2shows$ that the Ni-N (pendant imidate ester group) bond is rlatively strong; the Ni-N bond distance is shorter then the Ni-N(tertiary) distance and is similar to the Ni-N (secondary) distance.

Synthesis, Characterization, and Catalytic Properties of Gp 6 Metal Complexes of 1-N,N-dimethylaminomethyl-$1^{\prime}$,2-bis(diphenylphosphino)ferrocene (FcNPP). X-ray Crystal Structure of W$(CO)_4({\eta}^2-FcNPP(O)-P,N)$

  • Kim, Tae-Jeong;Kim, Yong-Hoon;Kim, Eun-Jin;Oh, Sang-Ho;Kim, Hong-Seok;Jeong, Jong-Hwa
    • Bulletin of the Korean Chemical Society
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    • 제15권5호
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    • pp.379-386
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    • 1994
  • Reactions of 1',2-bis(diphenylphosphino)-l-(N,N-dimethylaminomethyl)ferrocene (FcNPP) with $M(CO)_6$ (M=Cr, Mo, W) in the presence of TMNO (Trimethylamine oxide) in a stoichiometric ratio of 1 : 1.5 : 3.5 produced a series of Gp 6 metal carbonyl derivatives with a variety of coordination modes: M(CO)$_4({\eta}^2$-FcNPP-P,P) (M=Cr, Mo, W), $M(CO)_5({\eta}^1-FcNPP-P) (M=Mo, W)\;,\; M_2(CO)_9({\eta}^1\;,\;{\eta}^2-FcNPP-P,P,N) (M=Cr, Mo)\;,\;M_2(CO)_{10}({\eta}^1\;,\;{\eta}^1-FcNPP-P,P) (M=Cr, Mo, W)\;, and\;W(CO)_4({\eta}^2-FcNPP(O)-P,N)$. All these complexes were characterized by microanalytical and spectroscopic techniques. In one case, the structure of W(CO)$_4({\eta}^2$-FcNPP(O)-P,N) was determined by X-ray crystallography. Crystals are monocinic, space group P$2_{1/C}$, with a=10.147(2), b=19.902(3), c=19.821(4) ${\AA},\;{\beta}=96.88(2)^{\circ},\;V=3974(l){\AA}^3$, Z=4, and $D_{calc}=1.64 g cm^{-3}$. The geometry around the central tungsten metal is a distorted octahedron, with the nitrogen and phosphorus atoms being cis to each other. Some of these complexes exhibited catalytic activities in the allylic oxidation and epoxidation of cholesterly acetate. Other oxidation products were also formed with the different chemical yields and product distribution depending upon the ligand and the central metal.

기체상에서 Cu+ 및 Cu2+ 이온과 proline의 상호작용 (Interaction of Proline with Cu+ and Cu2+ Ions in the Gas Phase)

  • 이갑용
    • 대한화학회지
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    • 제53권3호
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    • pp.257-265
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    • 2009
  • $Cu^{+}$$Cu^{2+}$와 proline의 결합형태에 따른 구조 및 금속 친화도를 DFT(Density Functional Theory) 방법으로 조사하였다. 금속-proline의 결합과 여러 결합형태에 따른 에너지 순서는 $Cu^{+}$-Proline및 $Cu^{2+}$-proline 착화합물에서 서로 매우 상이함을 알았다. $Cu^{+}$-Proline의 경우, 바닥상태의 구조는 $Cu^{+}$가 중성 proline의 카르보닐 산소 및 이미노기 질소에 배위된 두 자리 배위를 하며, 이에 비해 $Cu^{2+}$-Proline 의 바닥상태의 구조는 zwitter이온 형태 proline의 카르복시기의 두 산소 사이에 chelation을 형성하는 구조임을 확인하였다. 가장 안정한 $Cu^{+}$-Proline 착화합물에서 proline의 금속 이온 친화도는 6-311++G(d,p) 수준에서 76.0 kcal/mol로 계산되었으며, proline의 $Cu^{2+}$ 이온 친화도는 258.5 kcal/mol로 나타났다.