• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3233-3238
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• 2013

Two new Cu(II) complexes, $[Cu_2(acpy-mdtc)_2(HBA)(ClO_4)]{\cdot}H_2O$ (1) (acpy-mdtc- = 2-acetylpyridine S-methyldithiocarbamate and $HBA^-$ = benzilic acid anion) and $[Cu_2(acpy-phtsc)_2(HBA)]{\cdot}ClO_4$ (2) (acpy-$phtsc^-$ = 2-acetylpyridine 4-phenyl-3-thiosemicarbazate) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single crystal X-ray diffraction. The X-ray analysis reveals that the structures of 1 and 2 are dinuclear copper(II) complexes bridged by two thiolate sulfur atoms of Schiff base ligand and bidentate bridging $HBA^-$ anion. For 1, each of the two copper atoms has different coordination environments. Cu1 adopts a five-coordinate square-pyramidal with a $N_2OS_2$ donor, while Cu2 exhibits a distorted octahedral geometry in a $N_2O_2S_2$ manner. For 2, two Cu(II) ions all have a five-coordinate square-pyramidal with a $N_2OS_2$ donor. In each complex, the Schiff base ligand is coordinated to copper ions as a tridentate thiol mode.

• 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.

• 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

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3617-3622
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• 2010

The reaction of stoichiometric amount of $FeCl_2{\cdot}4H_2O$, (2-pyridylmethyl, 3-pyridylmethyl)amine (2,3-pyma) and sodium azide/sodium thiocyanate in methanol under aerobic conditions affords the dinuclear Fe(III) complexes, [(2,3-pyma) $(N_3)_2Fe({\mu}-OCH_3)_2Fe(N_3)_2$(2,3-pyma)]${\cdot}CH_3OH$ (1) and [(2,3-pyma)$(NCS)_2Fe({\mu}-OCH_3)_2Fe(NCS)_2$(2,3-pyma)] (2) in good yield. Two bis-methoxy-bridged diiron(III) complexes are isolated and characterized. The coordination geometries around iron(III) ions in 1 and 2 are the same tetragonally distorted octahedron. The iron(III) ions are coordinated by two nitrogens of a 2,3-pyma, two nitrogens of two azide/thiocyanate ions, and two oxygens of two methoxy groups. Both compounds are isomorphous. The structures of 1 and 2 display the C-$H{\cdots}\pi$ and/or $\pi-\pi$ stacking interactions as well as hydrogen bonding interactions, respectively. Compounds 1 and 2 show significant antiferromagnetic couplings through the bridged methoxy groups between the iron(III) ions in the temperature range from 5 to 300 K ($H=-2JS_1{\cdot}S_2$, J=-19.1 and $-13.9\;cm^{-1}$ for 1 and 2).

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.634-640
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• 2005

The reaction of cis-[Cr([14]-decane)(OH$_2)_2]^+$ ([14]-decane = rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-teraazacyclotetradecane) with auxiliary ligands {$L_a$ = citrate(cit)} leads to a new dimeric complex cis-[{Cr([14]-decane)($\mu$-cit)}$_2](ClO_4)_2$. This binuclear complex has been structurally characterized by a combination of elemental analysis, conductivity, IR and Vis spectroscopy, mass spectrometry, and X-ray crystallography. Analysis of the crystal structure of cis-[{Cr([14]-decane)($\mu$-cit)})($_2]^+$ reveals that each chromium has a distorted octahedral coordination environment and citrato ligands are monodentate to the two chromium atoms via the carboxyl groups. For dimeric complex the bridging geometry is as follows: Cr$\ldots$Cr = 7.361 $\AA$; Cr-O(average) = 1.958 (8) $\AA$; Cr-N range = 2.108 (9)-2.147(9) $\AA$; N(1)-Cr-N(3) (equatorial position) = 98.0(4)$^{\circ}$; N(2)-Cr-N(4) (axial position) = 166.4(4)$^{\circ}$; O(1)-Cr-N(2) = 98.1(4)$^{\circ}$; O(3)-Cr-N(4) = 96.6(3)$^{\circ}$; O(1)-Cr-O(3) = 90.4$^{\circ}$. The FAB mass spectrum of the dimeric complex displays peak due to the molecular ions cis-[{Cr([14]-decane)($\mu$-cit)})($_2]^+$ at m/z 1053.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2043-2048
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• 2014

Two isomers of a new tetraaza macrotricycle 2,2,4,9,9,11-hexaazamethyl-1,5,8,12-tetraazatricyclo[$10.2.2^{5.8}$]-octadecane ($L^2$) containing additional N-$CH_2CH_2$-N linkages, C-meso-$L^2$ and C-racemic-$L^2$, have been prepared by the reaction of 1-bromo-2-chloroethane with C-meso-$L^1$ or C-racemic-$L^1$ ($L^1$ = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). Both C-meso-$L^2$ and C-racemic-$L^2$ react with copper(II) ion to form $[Cu(C-meso-L^2)]^{2+}$ or $[Cu(C-racemic-L^2)]^{2+}$ in dehydrated ethanol, but do not with nickel(II) ion under similar conditions. Crystal structure of [Cu(C-racemic-$L^2$)($H_2O$)]$(ClO_4)_2$ shows that the complex has distorted square-pyramidal coordination geometry with an apically coordinated water molecule. Unexpectedly, the Cu-N distances [2.016(3)-2.030(3) ${\AA}$] of [Cu(C-racemic-$L^2$)($H_2O$)]$(ClO_4)_2$ are longer than those [1.992(3)-2.000(3) ${\AA}$] of [Cu(C-racemic-$L^1$)($H_2O$)]$(ClO_4)_2$. As a result, $[Cu(C-racemic-L^2)(H_2O)]^{2+}$ exhibits weaker ligand field strength than $[Cu(C-racemic-L^1)(H_2O)]^{2+}$. The copper(II) complexes readily react with CN- ion to yield the cyano-bridged dinuclear complex $[Cu_2(C-meso-L^2)_2CN]^{3+}$ or $[Cu_2(C-racemic-L^2)_2CN]^{3+}$. Spectra and chemical properties of $[Cu(C-meso-L^2)]^{2+}$ and $[Cu_2(C-meso-L^2)_2CN]^{3+}$ are not quite different from those of $[Cu(C-racemic-L^2)]^{2+}$ and $[Cu_2(C-racemic-L^2)_2CN]^{3+}$, respectively.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.26-30
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• 2003

The dinuclear $Ag_2[Phen]_2[S_2P(OPr)_2]_2$(phen=1,10-phenanthroline; Pr=propyl), was prepared by the reaction of bis(dipropyldithiophosphato) silver(I) complex with 1,10-phenanthroline ligand, and its structure was determined by X-ray crystallography. The two dipropyldithiophosphato ligands each bridge two silver atoms to form an eight-membered $Ag_2S_4P_2$ ring, while the 1,10-phenanthroline molecule coordinates to a silver atom to complete the local tetrahedral geometry for the metal ion. The Ag-S bond distances are 2.559(1) and 2.567(1)${\AA}$, and the Ag-N bond distances are 2.366(3) and 2.471(3)${\AA}$.

• Journal of the Korean Applied Science and Technology
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• v.19 no.2
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• pp.103-107
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• 2002

Diphosphine dinuclear gold(I) complexes were synthesized from the reaction of bridged diphosphines and gold ions. As a bridged diphosphine, 1,2-bis(diphenylphosphino)metbane (dppm) or 1,1'-Bis(diphenylphosphino) ferrocene (dppf) was introduced. As anionic ligands, CI was first coordinated to Au, resulting in (diphosphine)$(AuCl)_{2}$. Then, the ligand, SPh, was substituted for Cl in the chloride complex to give (diphosphine)$(AuSPh)_{2}$. As a result, three digold complexes, (dppm)$(AuCl)_{2}$. (I), (dppf)$(AuCl)_{2}$. (II), and (dppf)$(AuSPh_{2}$. (III) were prepared in this study. The thermal properties were investigated at first hand to confirm that the gold complexes were in fact formed. The digold complexes were decomposed above $200^{\circ}C$ while the ligand, dppm or dppf, melts under $180^{\circ}C$ The photoluminescence (PL) spectra of the spin-coated thin films showed the maximum peak at 590, 595, and 540nm for the complex, I, II, and III, respectively. These complexes were found to give the orange color phosphorescence. Therefore, these digold complexes can be candidates for orange-red phosphorescent materials in organic electroluminescent devices (OELD). Further studies on application of the complexes as a dopant in an emitting layer are in progress in our laboratory.

• Journal of Photoscience
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• v.9 no.2
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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.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2597-2603
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• 2013

The reactions of hydrated $CdCl_2$, $MnCl_2$, and $NiCl_2$ with 2,2'-bipyidine-3,3',6,6'-tetracarboxylic acid ($H_4bptc$) afforded the mononuclear [$Cd^{II}(H_2bptc)(H_2O)_3]{\cdot}H_2O$ (1), linear $\{[Cd(H_2bptc)(H_2O)]{\cdot}3H_2O\}_n$ (2), 3-D heterobimetallic $[NaCd(Hbptc)(H_2O)]$ (3), layer $[Mn(H_2bptc)(H_2O)]_n$ (4) and a dinuclear compound $[Ni_2(H_2bptc)-(H_2O)_2]{\cdot}6H_2O$ (5). These compounds have been characterized by elemental analysis, IR, and their structures have been determined by X-ray crystallography. The thermal stabilities of 1-3 were measured by thermogravimetric analysis (TGA) and their solid state luminescence properties together with the free ligand $H_4bptc$ were investigated at room temperature.