X-ray crystal structures of carbonate and hydroxide bridged MnII/MgII heterobimetallic complexes formed by reduction of CO2 or H2O by a Mn0–MgII bonded compound

Jamie Hicks,Cameron Jones,Martin Juckel

doi:10.1515/mgmc-2021-0027

Abstract

Abstract The previously reported Mn0–MgII bonded heterobimetallic compound [L†Mn–Mg(MesNacnac)] (L† = −N(Ar†)(SiPri 3), Ar† = C6H2{C(H)Ph2}2Pri-2,6,4; MesNacnac = [(MesNCMe)2CH]−; Mes = mesityl) forms an adduct complex, [L†Mn–Mg(THF)(MesNacnac)], when dissolved in THF. Adventitious water is shown to be reduced by [L†Mn–Mg(MesNacnac)] to give the hydroxide bridged heterobimetallic, [L†Mn(μ-OH)2Mg(MesNacnac)]. The Mn0–MgII bonded heterobimtallic reductively disproportionates CO2, affording the carbonate bridged species, [{L†Mn(μ-CO3)Mg(THF) (MesNacnac)}2], in the presence of THF. The three new compounds have been crystallographically characterized.

Highlights

The chemistry of metal-metal bonded complexes has been intensively studied for decades (Liddle, 2015)
With regard to inorganic synthesis, one of the most fascinating applications of magnesium(I) complexes has been their use in the formation of compounds bearing unprecedented examples of unsupported Mg–metal bonds (Dange et al, 2019; Hicks et al, 2015)
We show that CO2 undergoes reductive disproportionation when reacted with 1, yielding a bimetallic carbonate complex, while partial hydrolysis of 1 gives a hydroxide bridged heterobimetallic

Summary

Introduction

The chemistry of metal-metal bonded complexes has been intensively studied for decades (Liddle, 2015). Most relevant to this study is the Mn0–MgII bonded compound 1 (Scheme 1), which was prepared by MgI reduction of a bulky amido manganese(II) bromide precursor (Hicks et al, 2014). Compound 1 contains a twocoordinate, high-spin, formally manganese(0) center, that is covalently bonded to a β-diketiminato magnesium(II) fragment.

Results

Conclusion