We use a variety of computational methods to characterize and compare the hydrogen atom transfer (HAT) and epoxidation reaction pathways for oxidation of cyclohexene by an iron(IV)-oxo complex. Previous B3LYP calculations have led to predictions that both alcohol (from the HAT route) and epoxide should be formed in similar amounts, which was not in agreement with experiment where only the HAT product was observed. We show here that ab initio calculations which can take both static and dynamic correlation into account are needed to explain the experimentally observed dominance of the HAT process. Since these systems do not have very strong multireference character we have also tested different flavours of local coupled cluster methods. We suggest that further improvements are necessary before they can provide highly accurate results for these systems.

中文翻译：

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非血红素铁反应性的能量学：从头算可以提供正确的答案吗？

我们使用多种计算方法来表征和比较氢原子转移（HAT）和环氧化反应途径，以通过铁（IV）-氧代络合物氧化环己烯。以前的B3LYP计算得出的预测是，醇（来自HAT途径）和环氧化物应以相似的量形成，这与仅观察到HAT产物的实验不一致。我们在这里显示从头开始需要进行考虑静态和动态相关性的计算以解释实验观察到的HAT过程的优势。由于这些系统不具有很强的多参考特性，因此我们还测试了不同口味的局部耦合聚类方法。我们建议需要进一步的改进，才能为这些系统提供高度准确的结果。