  Recently there has been much interest in the chirality induced spin
selectivity effect, whereby electron spin polarisation, which is dependent on
the molecular chirality, is produced in electrode-molecule electron transfer
processes. Naturally, one might consider if a similar effect can be observed in
simple molecular charge transfer reactions, for example in light-induced
electron transfer from an electron donor to an electron acceptor. In this work
we explore the effect of electron transfer on spins in chiral single radicals
and chiral radical pairs using Nakajima-Zwanzig theory. In these cases
chirality, in conjuction with spin-orbit coupling, does not lead to spin
polarisation, but instead the electron transfer generates quantum coherence
between spins states. In principle, this chirality induced spin coherence could
manifest in a range of experiments, and in particular we demonstrate that the
OOP-ESEEM pulse EPR experiment would be able to detect this effect in oriented
radical pairs.
