• Title/Summary/Keyword: dinuclear

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Preparation and Characterization of Dinuclear Metal Complexes, $[(PPh_3)_2(CO)M({\mu}-E)M(CO)(PPh_3)_2](SO_3CF_3)_2$ (M = Rh, Ir; E = 1,4-Dicyanobenzene and 1,4-Dicyano-2-butene)

  • Moonsik Kim;JaeKyun Chin;Jaejung Ko
    • Bulletin of the Korean Chemical Society
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    • v.13 no.5
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    • pp.556-559
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    • 1992
  • Hydrocarbon solution of $(PPh_3)_2(CO)MOSO_2CF_3$ (M= Rh, Ir) reacts rapidly with 1,4-dicyanobenzene or 1,4-dicyano-2-butene to yield dinuclear metal complexes $[(PPh_3)_2(CO)M({\mu}-dicyanobenzene)M(CO)(PPh_3)_2](SO_3CF_3)_2$ (I: M = Rh; II: M = Ir) or $[(PPh_3)_2(CO)M({\mu}-dicyano-2-benzene)M(CO)(PPh_3)_2](SO_3CF_3)_2$ (III: M = Rh; IV: M = Ir), respectively. Compounds I, II, III, and IV were characterized by $^1H$-NMR, $^{31}P$-NMR, and infrared spectrum. Dichloromethane solution of II and IV reacts with $H_2\;and\;I_2$ to yield oxidative addition complexes $[(PPh_3)_2(CO)IrX_2({\mu}-E)X_2Ir(CO)(PPh_3)_2](SO_3CF_3)_2$ (V; E = 1,4-dicyanobenzene, $X_2$ = $H_2$; VI : E = 1,4-dicyano-2-butene, $X_2$ = $H_2$; VII; E = 1,4-dicyanobenzene, $X_2$ = $I_2$). All metal complexes are bridged by the cyanide groups. Compounds Ⅴ, Ⅵ, and Ⅶ are characterized by conventional methods.

Effects of Structure of the Bridge on Polymerization Behavior of Dinuclear Constrained Geometry Catalysts and Properties of Ethylene-Styrene Copolymers (다리리간드의 구조가 이핵 CGC의 중합 특성과 생성된 에틸렌/스티렌 공중합체에 미치는 영향)

  • Pham, Nhat Thanh;Nguyen, Thi Dieu Huyen;Thanh, Nguyen Thi Le;Noh, Seok-Kyun
    • Polymer(Korea)
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    • v.35 no.1
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    • pp.77-86
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    • 2011
  • Polymerization properties of six dinuclear constrained geometry catalysts (DCGC) were investigated. The different length bridges of three catalysts were para-phenyl (Catalyst 1), para-xylyl (Catalyst 2), and para-diethylene phenyl (Catalyst 6). The other three DCGC have the same para-xylyl bridge with the different substituents at the phenyl ring of the bridge. The selected substituents were isopropyl (Catalyst 3), n-hexyl (Cataylst 4), and n-octyl (Catalyst 5), It was found that the longer catalyst not only exhibited a greater activity but also prepared a higher molecular weight copolymer. The catalyst 3 having a bulky isopropyl substituent revealed the lower activity but formed the highest molecular weight polymer comparing with the other alkyl substituted DCGCs. These results were able to be understood on the basis of the electronic and steric characteristics of the bridge. This study confirms that the control of the bridge structure of DCGC may contribute to control the microstructure of polymers.

Metal-Dinitrosyl Complexes(III) : Synthesis and Structural Study of Homo-, Hetero-dinuclear Molybdenum and Tungsten Complexes, $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(phen)Cl][ClO_4]_2 $(phen = 1,10-phenanthroline, pyz = pyrazine) (금속-디니트로실 착물 (제 3 보) : 몰리브덴과 텅스텐의 호모 및 헤테로 이핵 착물, $[Cl(phen)(NO)_2M({\mu}-pyz)M'(NO)_2(phen)Cl][ClO_4]_2 (phen=1,10-phenanthroline,\;pyz=pyrazine)$의 합성 및 구조에 대한 연구)

  • Sang-Oh Oh;Seong-Jong Mo
    • Journal of the Korean Chemical Society
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    • v.37 no.7
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    • pp.655-661
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    • 1993
  • The neutral monomeric compounds $[Mo(NO)_2Cl_2(phen)]$ and $[W(NO)_2Cl_2(phen)]$ (phen= 1,10-phenanthroline) have been prepared by reactions of polymeric compounds $[{Mo(NO)_2Cl_2}n],\;[{W(NO)_2Cl_2}n]$ with chelate ligands. Additions of one equivalent of silver(I) perchlorate to these cis-dinitrosyl compounds in acetone solution produce $[Mo(NO)_2(phen)(S)Cl][ClO_4]\;and\;[W(NO)_2(phen)(S)Cl][ClO_4]$ (S = acetone). The homo- and hetero-dinuclear complexes, $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][ClO_4]_2$ (M = Mo, W) and $[Cl(phen)(NO)_2M(pyz)M'(NO)_2(phen)Cl][C1O_4]_2$ (M = Mo, M' = W) have been prepared by these monocationic complexes with pyrazine ligand respectively. These complexes characterized by elemental analysis, $1^H-\;and\;^{13}C-NMR$, infrared, and UV-visible spectroscopy are reported. The spectral data indicate that homo- and hetero-dinuclear complexes were symmetrical structures of $C_{2v}$.

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Rhodium(III)-mediated cycloaddition reactions of alkynes

  • 한원석;이순원
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2002.11a
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    • pp.30-30
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    • 2002
  • Heating [Cp*Rh(η²-NO₃)(OTf) (1) and PhC≡CPh in EtOH for 3 h gave a η⁴-cyclobutadienerhodium complex, [Cp*Rh(η⁴-C₄Ph₄)] (2). Complex 1 reacted with HC=CPh in acetone at room temperature for 3 h to give a (η⁴-cyclobutadiene)-rhodium complex, [Cp*Rh(η⁴-C₄HPhC=CPh)] (3). Whereas, the reactions of 1 with HC=CCH₂Cl in acetone at room temperature for 3 h gave the triply halide-bridged dinuclear rhodium complex, [Cp*Rh(μ₂-Cl)₃RhCp*](OTf) (4). Complexes 2-4 have been structurally characterized by X-ray diffraction.

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Hydrolytic Kinetic Resolution of Racemic Alkyl-glycidyl Derivatives by using Dimeric Chiral Salen Catalyst Containing Ga, In and TlCl3 (염화갈륨, 인듐 및 탈륨 함유 이분자형 키랄 살렌 촉매에 의한 라세믹 알킬 글리시딜레이트 유도체의 비대칭 가수분해반응)

  • Shin, Chang-Kyo;Rahul, B. Kawthekar;Kim, Geon-Joong
    • Applied Chemistry for Engineering
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    • v.18 no.3
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    • pp.218-226
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    • 2007
  • The stereoselective synthesis of chiral terminal epoxides is of immense academic and industrial interest due to their utility as versatile starting materials as well as chiral intermediates. In this study, new dinuclear chiral Co (salen) complexes bearing gallium-, indium- and tallium-chloride have been synthesized and characterized. The mass and EXAFS spectra provided the direct evidence of formation of dinuclear complex. Their catalytic activity and selectivity have been demonstrated for the asymmetric ring opening of various terminal epoxides having ether or ester groups by hydrolytic kinetic resolution technology. The easily prepared dimeric complexes exhibited very high enantioselectivity for the asymmetric ring opening of epoxides with $H_2O$ nucleophile, providing enantiomerically enriched terminal epoxides (> 99% ee). The dimeric structured chiral salen showed remarkably enhanced reactivity and may be employed substantially lower loadings than its monomeric analogues. The system described in this work is very efficient for the synthesis of chiral epoxide and 1,2-diol intermediates

Self-assembly Coordination Compounds of Cu(II), Zn(II) and Ag(I) with btp Ligands (btp = 2,6-bis(N'-1,2,4-triazolyl)pyridine):Counteranion Effects

  • Kim, Cheal;Kim, Sung-Jin;Kim, Young-Mee
    • Korean Journal of Crystallography
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    • v.16 no.2
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    • pp.107-127
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    • 2005
  • Five Cu(II) compounds were obtained from different copper salts with btp ligands, and their structures were determined by X-ray crystallography. The structure of coordination polymer 2 contains btp-bridged tetranuclear Cu(II) units weakly connected by nitrate ions, and the structure of a discrete Cu(II) molecule 1 contains acetates and btp ligands. With perchlorate anions, two btp ligands bridge Cu(II) ions to form a double zigzag chain 3, while a single zigzag chain 4 is created with sulfate anions. The reaction of $Cu(NO_{3})_{2}$ containing $NH_{4}PF_{6}$ with btp ligands also produced a polymeric compound 5 containing $Cu(H_{2}O)_{2}^{2+}$ and $Cu(NO_{3})_{2}$ units alternatively bridged by btp ligands with H-bonds between copper bonded water and nitrate oxygen atoms. Five Zn(II) compounds were obtained from different zinc salts with btp ligands, and the structures of polymeric compounds (6, 7 and 8) and monomeric compounds (9 and 10) were determined by X-ray crystallography. With nitrate, chloride and bromide anions, btp ligands bridge Zn(II) ions to form polymeric compounds (6, 7 and 8), but btp ligands coordinate to a Zn(II) ion to form monomeric complexes (9 and 10) with $PF_{6}^{-}$ and perchlorate anions. Four silver salts and btp ligands produced two kinds of structures, dinuclear 20-membered rings and one-dimensional zigzag chain depending on different anions. For $ClO_{4}^{-}$ and OTf anions, weak interactions between Ag(I) and anions make dinuclear 20-membered rings construct polymeric compounds (11 and 13). For $PF_{6}^{-}$ anion, there are also weak interactions between Ag(I) and $F(PF_{6}^{-})(12)$, but they do not construct a polymeric compound. For $O_{2}CCF_{3}^{-}$ anion, btp ligands bridge Ag(I) atoms to make one-dimensional zigzag chain (14), and there are also interactions between Ag(I) and anions.

Synthesis and Characterization of Homo-, Hetero-Dinuclear Mo(Ⅲ) and V(Ⅲ) Complexes (Ⅳ) (몰리브덴(Ⅲ) 과 바나듐(Ⅲ) 호모 및 헤테로 이핵 착물의 합성과 특성 (제 4 보))

  • O, Sang O;Yu, Eun Yeong
    • Journal of the Korean Chemical Society
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    • v.38 no.11
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    • pp.808-818
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    • 1994
  • The neutral compounds [$MCl_3L_2$(MeCN)] (M = Mo, V: L = $PPh_3$, 1/2 phda) have been prepared from the reaction of starting material $MCl_z$ (M = Mo; z = 5, M = V; z = 3) with N,P-donating ligands in acetonitrile solution. Addition of $AgClO_4$ to these neutral monomeric compounds in acetone solution were produced [$MCl_3-_nL_2(MeCN)(S)_n$]$(ClO_4)_n$ (n = 1, 2 : s = solvent). Finally treatment of bivalent cationic compound and neutral compound was formed chloride bridged dinuclear complex $[(MeCN)(L)_2ClM({\mu}-Cl)_2M'Cl(L)_2(MeCN)](ClO_4)_2$ and treatment of univalent cationic compound with half equivalent pyrazine to pyrazine bridged complex $[(MeCN)(L)_2Cl_2M({\mu}-pyz)M'Cl_2(L)_2(MeCN)](ClO_4)_2$. These complexes are characterized by elemental analysis, $^1H$, $^{13}C$ NMR, IR, Far-IR and UV-Vis spectroscopy.

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Synthesis of Highly Enantiomerically Enriched Arenesulfonic Acid 2-Hydroxy Esters via Kinetic Resolution of Terminal Epoxides (속도론적 분할법을 통한 말단 에폭사이드로부터 고광학순도의 아렌술폰산 2-하이드록시 에스터의 합성)

  • Lee, Yae Won;Yang, Hee Chun;Kim, Geon-Joong
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.490-494
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    • 2016
  • This paper describes the very efficient and highly enantioselective ring opening of terminal epoxides with alkyl and arene sulfonic acid. The dinuclear chiral (salen) Co complexes bearing Lewis acids of Al, Ga and In catalyze the reaction enantioselectively in the presence of tetrabutylammonium chloride using tert-butyl methyl ether as a solvent. The variation of the anion of the tetra butyl ammonium salt has significant impact on the reactivity and selectivity of the asymmetric ring opening of phenyl glycidyl ether with p-toluenesulfonic acid. The order of reactivity and selectivity was found to be $Cl^-$ > $l^-$ > $Br^-$ > $OH^-$. Strong synergistic effects of the different Lewis acid centers of Co-Al, Co-Ga and Co-In complexes were observed in the catalytic process. The dinuclear chiral salen catalyst containing $AlCl_3$ was found to be most active and highly enantioselective (91% ee).