Redox active aluminium(iii) complexes convert CO2 into MgCO3 or CaCO3 in a synthetic cycle using Mg or Ca metal

Abstract

Redox-active Group 13 molecules possess the unusual combination of concomitant redox and acid–base reactivity. These combined properties enable regeneration of a metal hydroxide complex in a cycle for conversion of CO₂ into carbonate salts. Reaction of (IP⁻)₂Al(OH) (M = Al, Ga) with 1 atm of CO₂ affords [(IP⁻)₂Al]₂(μ²κ¹:κ²-OCO₂). Subsequent reduction affords MgCO₃ or CaCO₃ and two equivalents of [(IP²⁻)₂Al]⁻, which can be reoxidized to (IP⁻)₂Al(OH) to close a cycle.