Through-Space Ultrafast Photoinduced Electron Transfer Dynamics of a C₇₀-Encapsulated Bisporphyrin Covalent Organic Polyhedron in a Low-Dielectric Medium

High Resolution Image Download MS PowerPoint Slide Ultrafast photoinduced electron transfer (PIET) dynamics of a C 70 -encapsulated bisporphyrin covalent organic polyhedron hybrid (C 70 @COP-5) is studied in a nonpolar toluene medium with fluorescence and transient absorption spectroscopies. This structurally rigid donor (D)–acceptor (A) molecular hybrid offers a new platform featuring conformationally predetermined cofacial D–A orientation with a fixed edge-to-edge separation, R EE (2.8 Å), without the aid of covalent bonds. Sub-picosecond PIET (τ ET ≤ 0.4 ps) and very slow charge recombination (τ CR ≈ 600 ps) dynamics are observed. The origin of these dynamics is discussed in terms of enhanced D–A coupling ( V = 675 cm –1 ) and extremely small reorganization energy (λ ≈ 0.18 eV), induced by the intrinsic structural rigidity of the C 70 @COP-5 complex.