金属离子在液相氧化中的催化作用 XI.金属酞菁(MPc,M=Co、Fe)在异丙苯液相氧化中的催化作用

Catalytic Action of Metal Ions in the Liquid Phase Oxidation Ⅺ. The Catalytic Action of Metal-Phthalocyanine (MPc, M=Co, Fe) in the Liquid Phase Oxidation of Cumene

研究了MPc(M=CO、Fe)在异丙苯液相氧化中的催化作用,并考察了Py、bPy和菲绕啉等含N配体对MPc催化性能的影响.发现反应遵循配位-链锁反应机理.反应速度对异丙苯为1.5级,对催化剂为0.5级.反应活化能分别为53.1kJ/mol.(CoPe)和43.9 kJ/mol.(FePc).在所选择的反应条件下,异丙苯转化率较低(小于35%),生成过氧化氢异丙苯选择性约为100%.加入第五配体可使诱导期消失.电子光谱和反应动力学结果同时表明,反应是由O_2的配位活化引发的,ESR结果证明酞菁环的电子可和金属离子进行交换.

The catalytic action of MPc (M=Co, Fe) in the liquid phase oxidation of cumene was investigated. The effect of the addition of Py, bPy and phenathroline to the catalytic action of MPc was also studied. It was found that the reaction proceeded in accordance with the coordination-chain reaction mechanism. The reaction order with respect to cumene and MPc was about 1. 5 and 0. 5 respectively, in agreement with the theoretical value. The activation energy of the catalytic reaction was'53. 1 kJ/mol(CoPc) and 43. 9 kJ/mol (FePc) respectively. The selectivity for the formation of cumene hydroperoxide was approximately 100%. Addition of the fifth ligand eliminated the initiation period. The result of electronic spectroscopy and reaction kinetics indicated that the reaction was induced by the O2 coordinated with MPc. ESR result exhibited that the electron in the PC cycle could exchange with that in the metal ion.