Fig. 1: Synthesis of Btt-based COFs with the directionality and energy difference of the charge transition.
From: Dual donor-acceptor covalent organic frameworks for hydrogen peroxide photosynthesis

a Synthesis of TpaBtt, TapbBtt and TaptBtt. b Directionality of electron transfer between functional motifs and imine linkage in TpaBtt, TapbBtt, and TaptBtt. The yellow dashed lines represent motifs and red dashed lines represent imine bonds. The shade of the color represents the difference in energy.