Programmable energy transfer in multivariate porphyrin-based 3D covalent organic frameworks

Abstract

Efficient excited-state energy transfer (ET) is fundamental to artificial photosynthesis and solar energy conversion, yet conventional heterogeneous composites commonly suffer from nonradiative interfacial losses and limited structural precision. Herein, we report a family of multivariate porphyrin-based three-dimensional covalent organic frameworks (3D COFs) with bcu topology, in which electronically complementary benzimidazole donor and benzoselenadiazole acceptor chromophores are periodically integrated within a single crystalline lattice. The resultant TS-PCOF displays broadened visible-light absorption and pronounced donor–acceptor spectral overlap. Combined steady-state and time-resolved spectroscopic analyses reveal efficient intraframework ET on a sub-nanosecond timescale, delivering an ET efficiency of up to 23.8%. This work highlights multivariate 3D COFs as structurally precise platforms for programmable light harvesting and directional energy migration, providing a promising strategy for advanced photonic and solar-energy-conversion systems.