In this issue, H.-J. Himmel reviews electron-deficient triborane and tetraborane ring compounds. How are they synthesized, what structures and bonds are formed? The Minireviews deal with in situ amplification-based imaging of RNA in living cells (R. Yang et al.) and catalysis with palladium complexes photoexcited by visible light (V. Gevorgyan et al.). J. C. Chaput and P. Herdewijn share a Viewpoint on XNA. S. Mecking et al. look back on the life and works of Hans Herbert Brintzinger in an Obituary.

In the Original Research section, M. T. Mock et al. describe a catalytic ammonia oxidation to dinitrogen by hydrogen atom abstraction (see picture). B. H. Berrie et al. reveal the distribution of metal carboxylates in oil paint from the micro- to the nanoscale. P. Yang et al. present an organometallic americium complex. T. B. Poulsen et al. found a cyclopropene electrophile that targets glutathione S-transferase in omega-1 cells.

• Angewandte Chemie 34/2019: Forming Bonds,
  Angew. Chem. Int. Ed. 2019, 58 (34).