A bis ‐Pyrazolate Pincer on Reduced Cr Deoxygenates CO 2 : Selective Capture of the Derived Oxide by Cr II

Reduction of the bis ‐(pyrazolyl)pyridine complex [LCr] 2 with stoichiometric KC 8 in THF produces a species that is reactive with CO 2 to produce an aggregate composed of paramagnetic K 2 L 2 Cr 2 (CO 3 ) linked by KCl into a product of formula [K 2 L 2 Cr 2 (CO 3 )] 4 ⋅2KCl. X‐ray diffraction reveals a pincer hydrocarbon exterior and an inorganic interior composed of K + , Cl − and carbonate oxygens. Every Cr is five coordinate and square pyramidal, with the axial N donor weakly bonded to Cr due to the Jahn–Teller effect of a high spin d 4 configuration. Reaction with 13 CO 2 confirms that carbonate here is derived from CO 2 , that oxide is derived from CO 2 , and that CO is indeed released, since it is not a competent ligand to Cr II . Guiding principles for selectivity in CO 2 reduction are deduced from the diverse successful molecular constructs to date.