Abstract: | A new concept of the formation of charge transfer (CT) complexes between an intrinsically electron‐donating conjugated microporous polymer and a small molecule acceptor is reported. Spirobifluorene‐based mesoporous organic polymers with high porosity and Brunauer–Emmett–Teller surface area are synthesized by the Suzuki‐coupling reaction of spirobifluorene and pyrene monomers. The simple doping of the synthesized mesoporous, electron‐rich, conjugated polymer with 7,7,8,8‐tetracyanoquinodimethane as an acceptor leads to efficient CT complexation in the electron‐donating mesoporous spaces. This results in a high‐speed synthesis (within 5 s), thermally stable compound (up to about 200 °C), and good control of the concentration of donor–acceptor pairs in the CT complex. |