Identifying Sources of Entanglement Loss in Photodriven Molecular Electron Spin Teleportation

We report on an electron donor-electron acceptor-stable radical (D-A-R^•) molecule in which an electron spin state first prepared on R^• is followed by photogeneration of an entangled singlet ¹[D^•+-A^•-] spin pair to produce D^•+-A^•--R^•. Since the A^•- and R^• spins within D^•+-A^•--R^• are uncorrelated, spin teleportation from R^• to D^•+ occurs with a maximal 25% efficiency only for the singlet pair ¹(A^•--R^•) by spin-allowed electron transfer from A^•- to R^•. However, since ¹[D^•+-A^•-] is sufficiently long-lived, coherent spin mixing involving the unreactive ³(A^•--R^•) population affects entanglement and teleportation within D^•+-A^•--R^•. Pulse electron paramagnetic resonance experiments show a direct correlation between electron spin flip-flops and entanglement loss, providing information for designing molecular materials to serve as nanoscale quantum device interconnects.