Photoexcitation of electron donor-acceptor molecules frequently produces radical ion pairs with well-defined initial spin-polarized states that have attracted significant interest for spintronics. Transfer of this initial spin polarization to a stable radical is predicted to depend on the rates of the radical ion pair recombination reactions, but this prediction has not been tested experimentally. In this study, a stable radical/electron donor/chromophore/electron acceptor molecule, BDPA(center dot)-mPD-ANl-NDI, where BDPA(center dot) is alpha,gamma-bisdiphenylene-beta-phenylallyl, mPD is m-phenylenediamine, ANI is 4-aminonaphthalene-l,8-dicarboximide, and NDI is naphthalene-1,4:5,8-bis(dicarboximide), was synthesized. Photoexcitation of ANI produces the triradical BDPA(center dot)-mPD(+center dot)-ANI-NDI-center dot in which the mPD(+center dot)-ANI-NDI-center dot radical ion pair is spin coupled to the BDPA(center dot) stable radical. BDPA(center dot)-mPD(+center dot)- ANI-NDI-center dot and its counterpart lacking the stable radical are found to exhibit spin-selettive charge recombination,in which the triplet radical ion pair(3)(mPD(+center dot)-ANI-NDI-center dot) is in equilibrium with the (3)*NDI charge recombination product. Time-resolved EPR measurements show that this process is associated with an inversion of the sign of the Polarization transferred BDPA(center dot) over time. The polarization transfer rates are found to be Strongly solvent dependent, as shifts. in this equilibrium affect the spin dynamics. These results demonstrate that even small Changes in electron transfer dynamics can have a large effect on the spin dynamics Of photogenerated multispin systems.