새로운 N,N,O계 세 자리 리간드의 합성과 전위차적정법에 의한 전이금속 착물의 안정도상수의 결정

Abstract

Hydrobromic acid salts of new N, N, O tridentate ligands containing phenol, 2-[(2-Methylamino- ethyl- amino)-methyl]-phenol(H-MMP. 2HBr), 5-Bromo-2-[(2-Methylamino-ethylamino)-methyl]-phenol (Br- MMP. 2HBr), 5-Chloro-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Cl-MMP. 2HBr), 5-Methyl-2-[(2-Methylamino-ethylamino)-methyl]-phenol(Me-MMP. 2HBr), 5-Methoxy-2-I(2-Methylamino-ethylamino)- methyl]-phenol(MeO- MMP. 2HBr) and. 1-[(2-Methylamino-ethylamino)- methyl]-naphthalen-2-ol(Nap- MMP. 2HBr) were synthesized. The synthesized ligands were confirmed by C. H. N. atomic analysis, UV-visible and IR spectroscopies, <TEX>$^1$</TEX>H NMR, <TEX>$^{13}$</TEX>C NMR and mass analysis. The potentiometry study revealed that the proton dissociation constants(logK<TEX>$_n^H$</TEX>) of the synthesized ligands and stability constants (logK<TEX>$_{ML}$</TEX>, logK<TEX>$_{LM2}$</TEX>) of transition metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions occurred in three steps and the order of the calculated overall proton dissociation constants(log<TEX>$\beta_p$</TEX>) and stability constants (logK<TEX>$_{ML}$</TEX>) of ligands was Br-MMP. 2HBr < Cl-MMP 2HBr < H-MMP. 2HBr < Nap-MMP. 2HBr < Me-MMP. 2HBr < MeO-MMP. 2HBr. The order showed a similar trend to that of Hammett substituent constants(<TEX>$\delta_p$</TEX>). The synthesized ligands usually form 2:1(ML<TEX>$_2$</TEX>) complexes with transition metal ions. The order of the stability constants of each transition metal ions was Co(II) < Ni(II) < Cu(II) ;> Zn(II) ;> Cd(II) ;> Pb(II).