In this work we discuss the possibility of CO 2 activation by novel magnesium and zinc cryptate complexes. The choice of the complexes is partially based on the results of studies on CO 2 fixation by amidometal complexes and partially inspired by the mode of action of the RuBisCO enzyme. Quantum chemical calculations underline the potential of this new approach, and argue for reversible CO 2 activation and bonding to the cryptand complexes. We then report on the first steps towards an experimental realization and its limitations.