Three generations of cobalt porphyrins were synthesized, physicochemically characterized by FTIR and UV/Vis spectroscopy as well as cyclic voltammetry and applied as catalysts in the oxidation of cycloalkanes with atmospheric molecular oxygen under mild conditions. All examined catalysts were active in the tested reaction, and their catalytic activity varied with the nature and number of substituents on the porphyrin ring. Introduction of electron‐withdrawing or electron‐donating substituents at the porphyrin rings increases the activity of metalloporphyrin complexes. It was found, for the first time, that generation II cobalt porphyrins show higher activity in cycloalkane oxidation than cobalt porphyrins of generation III. The lower catalytic activity of generation III cobalt porphyrins can be attributed to the saddle‐shaped deformation of the porphyrin macrocycle. DFT modeling of Co porphyrins and their interactions with molecular oxygen provided explanations for the observed effects. On the basis of prior reports and the obtained results, a reaction mechanism is proposed and discussed.

中文翻译：

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三代钴卟啉在环烷烃氧化中的催化作用

合成了三代钴卟啉，通过FTIR和UV / Vis光谱以及循环伏安法对其物理化学进行了表征，并在温和条件下用作催化剂与大气分子氧氧化环烷烃。所有检查的催化剂在测试的反应中均具有活性，其催化活性随卟啉环上取代基的性质和数量而变化。在卟啉环上引入吸电子或供电子取代基会增加金属卟啉配合物的活性。首次发现，第二代钴卟啉在环烷烃氧化中的活性高于第三代钴卟啉。第三代钴卟啉的催化活性较低可归因于卟啉大环的鞍形变形。卟啉的DFT建模及其与分子氧的相互作用为观察到的效应提供了解释。在前人报道和所得结果的基础上，提出并讨论了反应机理。