In this issue, H. Braunschweig et al. review the role of boron in energy-related processes and applications. What makes this element unique if not critical in this field? The Minireviews deal with catalytically active peptide–gold nanoparticle conjugates (B. Koksch et al.) and armoring enzymes with metal–organic frameworks (G. Ouyang et al.). In an Essay, H.-W. Schmidt and F. Würthner introduce the idea of a periodic table of supramolecular elements. In Correspondences, S. Pan and G. Frenking challenge the interpretation of the chemical bond in NaBH₃⁻ proposed earlier by G. Liu et al.; the latter reply.

In the original research section, V. Schünemann et al. explore vibrations in spin–phonon coupling in single-molecule magnets by means of ¹⁶¹Dy nuclear resonance vibrational spectroscopy. H. Ito et al. present photoluminescent ferroelastic molecular crystals. A. K. Cheetham et al. describe the structural diversity and magnetic properties of hybrid ruthenium halide perovskites and related compounds (see picture). A. Deiters et al. controlled the CRISPR/Cas9 function in space and time in cells and zebrafish using light-activated guide RNA.

• Angewandte Chemie 23/2020: Unique and Critical,
  Angew. Chem. Int. Ed. 2020, 59 (23).