NMR and EPR Studies of Low-Spin Fe(III) Complexes of <i>m</i><i>eso</i>-Tetra-(2,6-Disubstituted Phenyl)Porphyrinates Complexed to Imidazoles and Pyridines of Widely Differing Basicities
作者:C. Todd Watson、Sheng Cai、Nikolai V. Shokhirev、F. Ann Walker
DOI:10.1021/ic0507316
日期:2005.10.1
A series of bis-axially ligated complexes of iron(III) tetramesitylporphyrin, TMPFe(III), tetra-(2,6-dibromophenyl)porphyrin, (2,6-Br2)4TPPFe(III), tetra-(2,6-dichlorophenyl)porphyrin, (2,6-Cl2)4TPPFe(III), tetra-(2,6-difluorophenyl)porphyrin, (2,6-F2)4TPPFe(III), and tetra-(2,6-dimethoxyphenyl)porphyrin, (2,6-(OMe)2)4TPPFe(III), where the axial ligands are 1-methylimidazole, 2-methylimidazole, and
铁(III)四茂
铁卟啉,
TMPFe(III),四-(
2,6-二溴苯基)
卟啉,(2,6-Br2)4
TPPFe(III),四-(
2,6-二氯苯基)
卟啉,(2,6-Cl2)4
TPPFe(III),四-(
2,6-二氟苯基)
卟啉,(2,6-F2)4
TPPFe(III)和四-(
2,6-二甲氧基苯基)
卟啉(2,6-(OMe)2)4
TPPFe(III),其中轴向
配体是
1-甲基咪唑,
2-甲基咪唑和一系列九个取代的
吡啶,碱度范围从4-(二
甲基氨基)
吡啶(pK(a )(PyH(+))= 9.70)制备3-和4-
氰基吡啶(pKa(PyH +)= 1.45和1.1),并通过EPR和1H NMR光谱进行了表征。在4.2 K处记录的EPR光谱显示“大g(max)”,菱形或轴向信号,具体取决于
卟啉铁和轴向
配体,00)显示了与简单居里行为的显着偏差,可以使用在此实验室中开发的温度相关拟合程序来拟合居里定律的扩展版本,该程序