Mimicking the oxygen evolution center: Making a synthetic analog of plant photosynthesis is a key goal for exploiting solar energy and replacing fossil fuels. Zhang et al. synthesized a manganese-calcium cluster that looks and acts like the oxygen evolution center in photosystem II (see the Perspective by Sun). The mimic structurally resembles the biological complex, with the notable exception of bridging protein ligands and water-binding sites on a dangling Mn atom. Functionally, however, the cluster's metal center readily undergoes four redox transitions, which contribute to splitting water into oxygen. This and other synthetic mimics will pave the way for developing more efficient catalysts for artificial photosynthesis. Science , this issue p. 690 ; see also p. 635

A novel family of heteronuclear Mn^IVCa–oxido complexes containing Mn^IVCa–oxido cuboidal moieties and reactive water molecules on Ca²⁺ have been synthesized and characterized to mimic the oxygen-evolving complex (OEC) of photosystem II (PSII) in nature.

A novel heterometallic MnSr complex containing the Mn₃SrO₄ cuboidal moiety and all types of μ-O²⁻ moieties observed in the oxygen-evolving complex (OEC) in Sr²⁺-containing photosystem II (PSII) has been synthesized and characterized, which provides a new synthetic model of the OEC.