Porphyrin Antennas on Carbon Nanodots: Excited State Energy and Electron Transduction.

We report the synthesis and electron donor-acceptor features of a novel nanohybrid, in which the light-harvesting and electron-donating properties of a meso-tetraarylporphyrin (TArP) are combined with the electron-accepting features of nitrogen-doped carbon nanodots (NCNDs). In particular, in an ultrafast process (>10(12)  s(-1) ), visible-light excitation transforms the strongly quenched porphyrin singlet excited states into short-lived (225 ps) charge-separated states. On the other hand, ultraviolet light excitation triggers a non-resolvable transduction of singlet excited state energy from the NCNDs to the porphyrins, followed by the same charge separation observed upon visible light excitation.