In this issue, J. Yuan et al. review porous polyelectrolytes. How does the interplay of charge and pores lead to new functionalities? In a Minireview, P. J. Rayner and S. B. Duckett summarize magnetic resonance signal amplification by reversible exchange. The Highlight deals with metal-free nitrogen fixation at boron (C. Hering-Junghans). In his Editorial, P. Adelhelm shows why simple math matters in the context of the energy challenge and batteries. U. Lüning and M. Schmittel look back on the life and scientific achievements of Christoph Rüchardt in an Obituary.

In the Communications section, N. Martín et al. present the synthesis of a helical bilayer nanographene (see picture). A. I. Krylov et al. calculated distinct electron conductance regimes in bacterial decaheme cytochromes. K. T. Park et al. reduced CO₂ to formate in a catholyte-free electrocatalytic reaction. B. Morandi et al. succeeded in the iron-catalyzed ring-closing C–O/C–O metathesis of aliphatic esters.

• Angewandte Chemie 23/2018: Interplay,
  Angew. Chem. Int. Ed. 2018, 57 (23).