In this issue, Y. Luo et al. review functional nucleic acid nanomaterials. How did synthetic methods, properties, and applications evolve? The Minireviews deal with transition-metal-catalyzed insertion reactions with donor/donor carbenes (L. W. Souza et al.) as well as syntheses, reactions, and applications of vinyl and alkynyl triazenes (A. A. Suleymanov, K. Severin). C. A. Mirkin et al. share a Viewpoint on the origins of multiply twinned colloidal nanoparticles.

In the original research section, Z.-Y. Gu et al. show how to control the stacking modes of metal–organic framework nanosheets through host–guest noncovalent interactions. M. Kalesse et al. report the total synthesis of chondrochloren A. S.-L. You et al. succeeded in the visible-light-induced intramolecular double dearomative cycloaddition of arenes. Molecular simulations by A. J. Mulholland et al. suggest vitamins, retinoids, and steroids as ligands of the free fatty acid pocket of the SARS-CoV-2 spike protein (see picture). A. Walther et al. found a chemically fueled volume phase transition of polyacid microgels.

• Angewandte Chemie 13/2021: Phase Transitions,
  Angew. Chem. Int. Ed. 2020, 60 (13).