• Title/Summary/Keyword: Pyridylmethyl groups

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Synthesis and Properties of Tetraaza Macrocycles Containing Two 3-Pyridylmethyl, 4-Pyridylmethyl, or Phenylmethyl Pendant Arms and Their Nickel(Ⅱ) and Copper(Ⅱ) Complexes: Effects of the Pendant Arms on the Complex Formation Reaction

  • Kang, Shin-Geol;Kim, Seong-Jin
    • Bulletin of the Korean Chemical Society
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    • v.24 no.3
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    • pp.269-273
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    • 2003
  • The synthesis and properties of 2,13-bis(3'-pyridylmethyl) $(L^3)$, 2,13-bis(4'-pyridylmethyl) $(L^4)$, and 2,13-bis(phenylmethyl) $(L^5)$ derivatives of 5,16-dimethyl-2,6,13,17-tetraazatrcyclo$[16.4.0.^{1.18}0^{7.12}]$docosane are reported. The 3- or 4-pyridylmethyl groups of $[ML^3](ClO_4)_2\;or\;[ML^4](ClO_4)_2$ (M = Ni(Ⅱ) or Cu(Ⅱ)) are not involved in coordination, and the coordination geometry (square-planar) and ligand field strength of the complexes are quite similar to those of $[ML^5](ClO_4)_2$, bearing two phenylmethyl pendant arms. However, the complex formation reactions of $L^3\;and\;L^4$ are strongly influenced by the pyridyl groups, which can interact with a proton or metal ion outside the macrocyclic ring. The macrocycle $L^5$ exhibits a high copper(Ⅱ) ion selectivity against nickel(Ⅱ) ion; the ligand readily reacts with copper(Ⅱ) ion to form $[CuL^5]^{2+}$ but does not react with hydrated nickel(Ⅱ) ion in methanol solutions. On the other hand, $L^3\;and\;L^4$ form their copper(Ⅱ) and nickel(Ⅱ) complexes under a similar condition, without showing any considerable metal ion selectivity. The ligands $L^3\;and\;L^4$ react with copper(Ⅱ) ion more rapidly than does $L^5$ at pH 6.4. At pH 5.0, however, the reaction rate of the former macrocycles is slower than that of the latter. The effects of the 3- or 4-pyridylmethyl pendant arms on the complex formation reaction of $L^3\;and\;L^4$ are discussed.

Crystal Structure of $[Ni(L)](ClO_4)_2$ (L: 2,13-bis(2-pyridylmethyl)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,$0^{1.18},0^{7.12}$]docosane) ($[Ni(L)](ClO_4)_2$(L: 2,13-bis(2-pyridylmethyl)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,$0^{1.18},0^{7.12}$docosane) 착물의 결정구조)

  • Park, Ki-Young;Suh, Il-Hwan;Kim, Jing-Gyu;Park, Young-Soo
    • Korean Journal of Crystallography
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    • v.10 no.1
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    • pp.88-93
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    • 1999
  • The complex [Ni(L)](ClO4)2 (1) (L=2,13-bis(2-pyridylmethyl)-3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.1807.12]docosane) has been synthesized and characterized by X-ray crystallography. (1) crystallizes in the triclinic, space group P, with a=10.948(2), b=10.948(2), c=14.911(4) , α=93.73(2), β=93.77(2), γ=99.29(2)o, V=1754.8(7) 3, Z=2, R1(wR2) for 5217 observed reflections of [I>2σ(I)] was 0.048(0.099). The coordination environment around nickel(II) ion shows a distorted octahedron with four secondary and tertially amines of the macrocycle and two nitrogen atoms of pyridylmethyl groups.

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Synthesis, Crystal structure, and Magnetic Properties of Dinuclear Iron(III) Complexes with Methoxo Bridges

  • Shin, Jong-Won;Han, Jeong-Hyeong;Rowthu, Sankara Rao;Kim, Bong-Gon;Min, Kil-Sik
    • 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).