Diverse outcomes of CO fixation using alkali metal amides including formation of a heterobimetallic lithium-sodium carbamato-anhydride lithium-sodium bis-hexamethyldisilazide

Fixation of CO 2 by lithium amides derived from pyrrole and diisopropylamine generates a lithium carbamate polymer and dodecamer respectively. Moving to lithium-sodium hexamethyldisilazide produces a more complicated, intriguing reaction, where unusually the bimetallic composition is maintained in the product but its composition contains both carbamato and anhydride functionalities. Mixed-metal synergistic activation of CO 2 leads to a crystalline mixed-metal carbamato-anhydride polymer.