Frontispiece: Renaissance of Topotactic Ion‐Exchange for Functional Solids with Close Packed Structures

Synthetic transformations of close-packed structures have witnessed a budding renaissance with the use of topotactic ion-exchange reactions. Surprising pathways to many new multifunctional and metastable solids have been discovered by leveraging the ion mobilities within their underlying sublattices. Recent research has begun elucidating many of the key synthetic variables, such as highlighted in the article frontispiece. For more information, please see the Concept article by Maggard et al. on page 19–24 https://doi.org/10.1002/chem.202200479.