Fig. 4: Transient absorption spectroscopy and charge transfer kinetics of BTBpy and TpBpy COFs.

TA spectra of a BTBpy and d TpBpy excited at 400 nm. Time slices of the TA spectra of b BTBpy and e TpBpy in water. TA kinetics of c BTBpy probed at 475 nm, 570 nm, and 720 nm, and f TpBpy probed at 510 nm and 650 nm. Schematic of electron transitions for g BTBpy and h TpBpy. i Charge transfer kinetic constants derived from TA kinetics.