Encapsulation makes the difference!. A β‐cyclodextrin‐based diphosphane ligand with metal confining properties is key in the stabilization of heteroleptic Cu(I) complexes. In their Research Article (e202214638), Nicola Armaroli, Béatrice Delavaux‐Nicot, Jean‐François Nierengarten, Dominique Armspach et al. show how encapsulation of the metal‐bound diimine ligand moiety in the cyclodextrin cavity influences their electronic properties. In particular, flattening of the metal tetrahedral geometry in the excited state is largely prevented thus resulting in enhanced luminescent properties.