A DFT analysis of a covalent organic donor-acceptor-radical molecule used for quantum teleportation

Radical ion pairs (RIPs) have been used to demonstrate quantum teleportation in molecular systems for applications in quantum information science. Covalent organic donor-acceptor (D-A) molecules can produce RIPs through photo-induced charge transfer  and an additional radical (R) molecule makes quantum teleportation possible. We present the electronic structure and analyze charge transfer excited states of a recently studied[1] D-A-R molecular system using density functional theory. The distances between donor-acceptor and donor-radical are about 12.9 Å and 21.9 Å, respectively. The excitation energies are calculated using the perturbative delta-SCF method and agree with other conventional excited-state methods and experimental reference values. Charge transfer energies change with solvent polarity, but we find that due to the ionic nature of triad, even low polarity solvents make a significant change in energies. We discuss the spin ordering energies and the Heisenberg exchange coupling parameters for this D-A-R system.

 

[1] Rugg, B.K. et al. Photodriven quantum teleportation of an electron spin state in a covalent donor–acceptor–radical system. Nat. Chem. 11, 981–986 (2019).