Greta G. Zámbó, Carla A. Esslinger, Michael J. Sauer, Isabelle Rüter, Robert M. Reich, Serhiy Demeshko, Franc Meyer, Fritz E. Kühn
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引用次数: 0
Abstract
The first macrocyclic abnormal N-heterocyclic carbene (aNHC) FeIII complex, featuring a calix[4]3-methyl-1,2,3-triazole-5-ylidene ligand system is synthesised and characterised inter alia via EA, SC-XRD, NMR and UV/vis spectroscopy. Including Mössbauer spectroscopy, SQUID and DFT calculations, the impact of the aNHC on the FeIII complex and its corresponding FeII derivative is investigated. A comprehensive study of the aNHC Fe complexes in their performance in homogenous epoxidation reactions is reported and compared to the established benchmark catalysts. The complexes demonstrate efficient and selective catalytic activity in the epoxidation of cis-cyclooctene with H2O2, with TOFs up to almost 60 000 h−1. Additionally, the epoxidation of more challenging olefinic substrates is possible. The reactivity under oxidative conditions of both complexes is investigated. NMR measurements reveal the formation of a mono-oxidised triazole ligand as degradation product. HR-ESI-MS measurements, supported by DFT calculations indicate the formation of an oxoiron species.
期刊介绍:
A multidisciplinary journal focusing on cutting edge research across all fundamental science and technological aspects of catalysis.
Editor-in-chief: Bert Weckhuysen
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