Conjugated covalent networks: Although graphene and related materials are two-dimensional (2D) fully conjugated networks, similar covalent organic frameworks (COFs) could offer tailored electronic and magnetic properties. Jin et al. synthesized a fully π-conjugated COF through condensation reactions of tetrakis(4-formylphenyl)pyrene and 1,4-phenylenediacetonitrile. The reactions were reversible, which provides the self-healing needed to form a crystalline material of stacked, π-bonded 2D sheets. Chemical oxidation of this semiconductor with iodine greatly enhanced its conductivity, and the radicals formed on the pyrene centers imparted a high spin density and paramagnetism. Science , this issue p. 673

The spatial charge arrangement of a typical quasi-two-dimensional organic conductor α-(BEDT-TTF) 2 I 3 is revealed by single crystal structure analysis using synchrotron radiation. The results show that the horizontal-stripe-type structure, which was suggested by the mean field theory, is established. We also find the charge disproportionation above the metal–insulator transition temperature and a significant change in the transfer integrals caused by the phase transition. Our result elucidates the insulating phase of this material as the 2 k F charge density localization.