Reversible Uptake of CO2by Pincer Ligand Supported Dimetallynes

AbstractWe report on the reversible uptake of carbon dioxide by dimetallynes featuring ancillary hemi‐labile pincer ligands. Insertion into the Ge−Ge/Sn−Sn bonds yields species containing an E(CO2)E unit, with the mode of ligation of the CO2fragment determined crystallographically being found to be dependent on the identity of the Group 14 element. The thermodynamics of CO2uptake/loss can be established through VT NMR (ΔH°=+24.6(2.3) kJ mol−1, ΔS°=+64.9(3.8) J mol−1 K−1, ΔG°298=+5.3(1.9) kJ mol−1for the loss of CO2in the Ge case), and the chemical consequences of reversibility demonstrated by thermodynamically‐controlled exchange reactions.