In this issue, Q. Zhang et al. review intrinsic electrocatalytic activity regulation of M-N-C single-atom catalysts for the oxygen reduction reaction. The Minireviews deal with polymerized small-molecule acceptors for high-performance all-polymer solar cells (Z.-G. Zhang, Y. Li) and enzymatic kinetic resolution by addition of oxygen (J. Robertson et al.). A. Roy and M. Oestreich highlight the use of Me₃Si as a masked alcohol, and D. E. Lewis discusses the logic behind Markovnikov’s rule in an Essay.

In the original research section, C. Chi et al. present a stable [4,3]peri-acene diradicaloid (see picture). P. Schwille et al. show how to fine-tune protein self-organization by orthogonal chemo-optogenetic tools. E. Yashima et al. found that a racemic monomer-based one-handed helical polymer recognizes enantiomers through auto-evolution of its helical handedness excess. K. T. Nam et al. captured manganese oxide intermediates in electrochemical water oxidation at neutral pH by in situ Raman spectroscopy.

• Angewandte Chemie 9/2021: The Logic Behind,
  Angew. Chem. Int. Ed. 2020, 60 (9).