In this issue, B. Z. Tang et al. review multicolor fluorescent polymeric hydrogels and Y. K. Loh and S. Aldridge discuss progress on acid–base-free main group carbonyl analogues. In his Nobel lecture, M. Rosbash describes circadian rhythms and the transcriptional feedback loop. The Minireviews deal with the production of carbon quantum dots and their integration with polymers (S. Chen et al.) and spatiotemporal delivery of CRISPR/Cas9 genome editing machinery (M. Wang et al.).

In the original research section, Z. Wu et al. demonstrate the traceless removal of two kernel atoms in a gold nanocluster (see picture). W. Tiznado et al. found planar hexacoordinate carbons to be half covalent, half ionic. C. Boyer et al. succeeded in 3D printing and surface functionalization via type I photoinitiated RAFT polymerization. V. Y. Chen and O. Kwon present a unified approach to furan natural products via phosphine–palladium catalysis.

• Angewandte Chemie 16/2021: Half and Half,
  Angew. Chem. Int. Ed. 2020, 60 (16).