Donor-dimensionality-modulated excited state in conjugated microporous polymers for enhanced photocatalysis

Precise excited-state control in donor-acceptor conjugated microporous polymers (CMPs) is essential for photocatalysis but challenging due to energy losses from locally excited (LE) states. We report a dimensionality modulation strategy for donor units to suppress LE-mediated intersystem crossing (ISC) and enhance charge-transfer (CT) states. Three different CMPs coupling a thiophene- S , S -dioxide (SO) acceptor with one-dimensional (1D) phenylene, two-dimensional (2D) pyrene, and three-dimensional (3D) tetraphenylethene donors were synthesized. The 2D pyrene-based Py-SO-CMP exhibits superior photocatalytic tetracycline degradation, with a rate constant 45 times that of its 1D analog. It maintains >90% removal for 50 h in flow systems with complete detoxification confirmed. Transient spectroscopy and modeling attribute this to delocalized CT states, ultralow exciton binding energy (54.92 meV), and minimized triplet losses. This work establishes donor-dimensionality control to mitigate ISC losses and enhance excited-state utilization.