Synthesis of hydroxo-bridged Dy(iii) dimers supported by crown ethers through C–H activation and oxygen-atom transfer of Me3NO

Abstract

Me₃NO is well known for undergoing an oxygen-atom transfer reaction, while the C–H activation of Me₃NO with organometallic complexes is far less explored. Herein, we report the synthesis and characterization of two hydroxo-bridged dinuclear complexes [Dy(12-crown-4)(µ-OH)(CH₃CN)I]₂I₂(CH₃CN)₂ (3) and [Dy(15-crown-5)(µ-OH)(CH₃CN)]₂I₄ (4), which were formed by the reactions of different crown ether supported complexes [Dy(12-crown-4)₂(CH₃CN)]I₃ (1) and [Dy(15-crown-5)(CH₃CN)₂I]I₂ (2) with Me₃NO, respectively. The observation of bridging hydroxo groups in complexes 3 and 4 indicates that Me₃NO underwent C–H activation along with OAT during the reactions. In contrast, the reactions of 1 and 2 with H₂O led to two hydrated adducts [Dy(12-crown-4)₂(H₂O)](CH₃CN)₃I₃ (5) and [Dy(15-crown-5)(CH₃CN)₂(H₂O)]I₃ (6), respectively.