Stable Luminescent [Cu(NN)(PP)]<sup>+</sup> Complexes Incorporating a β‐Cyclodextrin‐Based Diphosphane Ligand with Metal‐Confining Properties
Tuan‐Anh Phan, Nicola Armaroli, Alejandra Saavedra Moncada, Elisa Bandini, Béatrice Delavaux‐Nicot, Jean‐François Nierengarten, Dominique Armspach
Abstract
Abstract A β‐cyclodextrin‐based diphosphane with metal‐confining properties was efficiently synthesized thanks to an unprecedented Smiles‐like rearrangement of diphenyl‐(2‐phosphanylphenyl)phosphane in the presence of excess n ‐BuLi. The cis ‐chelating bidentate ligand is capable of forming very stable heteroleptic [Cu(NN)(PP)] + complexes in which a metal‐bound diimine ligand (bpy, phen, or mmp) is located within the cyclodextrin cavity. As a result of ligand encapsulation, flattening of the metal tetrahedral geometry in the excited state is disfavored, thereby resulting in enhanced luminescent properties.