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nfluence of Ligand Architecture on Oxidation Reactions by High-Valent Nonheme Manganese Oxo Complexes Using Water as a Source of Oxygen

投稿者: Yuma Morimoto
  1. 同じ配位子を持つ鉄四価およびマンガン四価オキソ錯体の反応パスの違いについて考察した論文。
  1. 新規に合成したマンガン錯体は、鉄錯体より反応性が低かった。
  1. それは反応に関与する軌道が、鉄の際は酸素と鉄のσ＊で、マンガンはπ＊で、π＊のほうが支持配位子に囲まれていて、空間的に混み合っているせいで、反応しにくいという結論

  1. Prasenjit Barman1, 
  2. Dr. Anil Kumar Vardhaman1, 
  3. Dr. Bodo Martin2, 
  4. Svenja J. Wörner2, 
  5. Dr. Chivukula V. Sastri1,*and
  6. Prof. Dr. Peter Comba2,*
Article first published online: 29 DEC 2014
DOI: 10.1002/anie.201409476

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Keywords:

  • density functional calculations;
  • isomers;
  • manganese;
  • oxidation;
  • structure elucidation

Abstract

Mononuclear nonheme MnIV[DOUBLE BOND]O complexes with two isomers of a bispidine ligand have been synthesized and characterized by various spectroscopies and density functional theory (DFT). The MnIV[DOUBLE BOND]O complexes show reactivity in oxidation reactions (hydrogen-atom abstraction and sulfoxidation). Interestingly, one of the isomers (L1) is significantly more reactive than the other (L2), while in the corresponding FeIV[DOUBLE BOND]O based oxidation reactions the L2-based system was previously found to be more reactive than the L1-based catalyst. This inversion of reactivities is discussed on the basis of DFT and molecular mechanics (MM) model calculations, which indicate that the order of reactivities are primarily due to a switch of reaction channels (σ versus π) and concomitant steric effects.


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