Acta Chimica Sinica ›› 1995, Vol. 53 ›› Issue (9): 861-866. Previous Articles     Next Articles

Original Articles

尾式金属卟啉配合物的研究IV: 含氮配体与尾式铁(III)卟啉轴向配位反应热力学及其配位模式

焦向东;黄锦汪;计亮年   

  1. 中山大学化学系
  • 出版日期:1995-09-15 发布日期:1995-09-15

Studies on tailed metalloporphyrin coordination compounds IV: Thermodynamics for the axial addition of nitrogenous ligands to tailed porphyrin iron(III) complexes and the novel coordination mode

JIAO XIANGDONG;HUANG JINWANG;JI LIANGNIAN   

  • Online:1995-09-15 Published:1995-09-15

Coordination properties between two new tailed porphyrin iron (III) complexes, 5[o-(4-(1-imidazolyl)butoxy)phenyl]-10,15,20-triphenylporphyrinatoiron (III) chloride {[Fe^I^I^I(ImTPP)]Cl} and 5-[p-(4-(3-pyridyloxyl)butoxyl]phenyl-10,15,20-triphenylporphyrinatoiron (III) chloride {[Fe^I^I^I(PyTPP)]Cl}, with nitrogenous ligands and the equilibrium constants for the addition of these ligands to [Fe^I^I^IP]Cl in chloroform were studied by spectral technique. Experimental results demonstrated that [Fe^I^I^I(PyTPP)]Cl, just similar to [Fe^I^I^I(TPP)]Cl, form 1:2 adducts with imidazole or pyridines, respectively, but (Fe^I^I^I(ImTPP)]Cl forms only 1:1 adducts with pyridines and form 1:2 adduct with imidazole. The equilibrium constants for the addition of nitrogenous ligands to [Fe^I^I^I(ImTPP)]Cl are 10-10^3 times as big as those for [Fe^I^I^I(TPP)]Cl system. We believe that this result is from the fact that the axial coordination of these ligands to [Fe^I^I^I(ImTpp)]Cl induces the coordination of terminal imidazole group with ferric iron in [Fe^I^I^I(ImTpp)]Cl and this kind of coordination mode strengthens the bonding between ferric ion in [Fe^I^I^I(ImTpp)]Cl and nitrogen atom in ligand. The novel coordination mode and its structure were identified by the experimental data from UV-vis, ^1H NMR and low-temperature EPR.

Key words: ULTRAVIOLET SPECTROPHOTOMETRY, SPECTROPHOTOMETRY, IRON COMPLEX, PYRIDINE, IMIDAZOLE, PROTON MAGNETIC RESONANCE SPECTROMETRY, PORPHYRIN

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