10.1021/jacs.5b06454.s001 Olga Trukhina Olga Trukhina Marc Rudolf Marc Rudolf Giovanni Bottari Giovanni Bottari Takeshi Akasaka Takeshi Akasaka Luis Echegoyen Luis Echegoyen Tomas Torres Tomas Torres Dirk M. Guldi Dirk M. Guldi Bidirectional Electron Transfer Capability in Phthalocyanine–Sc<sub>3</sub>N@<i>I</i><sub><i>h</i></sub>–C<sub>80</sub> Complexes American Chemical Society 2015 photophysical assays easy-to-purify endohedral metallofullerenes milestone en-route Zn Sc 3 N latter ensemble electron transfer dichotomy Bidirectional Electron Transfer Capability switchable electron transfer reactivity building block pyridyl-substituted Sc 3 N C 60 2015-10-14 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Bidirectional_Electron_Transfer_Capability_in_Phthalocyanine_Sc_sub_3_sub_N_i_I_i_sub_i_h_i_sub_C_sub_80_sub_Complexes/2121832 To activate oxidative and/or reductive electron transfer reactions, <i>N</i>-pyridyl-substituted Sc<sub>3</sub>N@<i>I</i><sub><i>h</i></sub>–C<sub>80</sub> (<b>4</b>) and C<sub>60</sub> (<b>3</b>) fulleropyrrolidines have been prepared and axially coordinated to electron-rich (<b>1</b>) or electron-deficient (<b>2</b>) Zn­(II)­phthalocyanines (Zn­(II)­Pcs) through zinc-pyridyl, metal–ligand coordination affording a full-fledged family of electron donor–acceptor ensembles. An arsenal of photophysical assays as they were carried out with, for example, <b>1</b>/<b>4</b> and <b>2</b>/<b>4</b> show unambiguously that a Zn­(II)­Pc-to-Sc<sub>3</sub>N@<i>I</i><sub><i>h</i></sub>–C<sub>80</sub> photoinduced electron transfer takes place in the former ensemble, whereas a Sc<sub>3</sub>N@<i>I</i><sub><i>h</i></sub>–C<sub>80</sub>-to-Zn­(II)­Pc electron transfer occurs in the latter ensemble. To the best of our knowledge, this is the first time that a fullerene-based molecular building block shows an electron transfer dichotomy, namely acting both as electron-acceptor or electron-donor, and its outcome is simply governed by the electronic nature of its counterpart. In light of the latter, the present work, which involves the use of Sc<sub>3</sub>N@<i>I</i><sub><i>h</i></sub>–C<sub>80</sub>, one of the most abundant and easy-to-purify endohedral metallofullerenes, is, on one hand, a paradigmatic change and, on the other hand, an important milestone <i>en-route</i> toward the construction of easy-to-prepare molecular materials featuring switchable electron transfer reactivity.