Revisiting Bond Breaking and Making in EuCo ₂ P ₂ : Where are the Electrons?

“The concept of formal oxidation states is frequently used by chemists to achieve an adequate understanding of correlations between the composition, structure, and properties of molecules and materials. In this work, we demonstrate that such formal charges become inadequate when one deals with metallic systems with delocalized bonding, where electronic states of different elements are strongly mixed.” Read more about the story behind the cover in the Cover Profile and about the research itself on page 5865 ff. (DOI: 10.1002/chem.201900244).