Figure 2.
Red: Elements for which luminescent complexes have long been known but important conceptual progress has been made recently. Yellow: A few selected luminescent complexes were known for these elements, and a few more examples have been added recently. Green: New elements on the landscape of emissive molecular complexes in solution at room temperature. Gray: Many luminescent ZnII complexes are known, but they typically feature ligand-centered emission. White: Elements for which room temperature emission in solution still remains a challenge and no recent reports have appeared. Spin states and appertaining oxidation states of so far known examples of luminescent molecular complexes in solution at room temperature are listed below the individual elements.