Transient electron paramagnetic resonance (TREPR) spectroscopy has been used to study the spin-spin interactions in a novel U-shaped electron donor-chromophore-acceptor-radical (D-C-A-R-center dot) system in which a xanthene bridge holds a tert-butylphenyl nitroxide (BPNO center dot) radical in close proximity to a naphthalene-1,8:4,5-bis(dicarboximide) (NDI) acceptor. Photoexcitation of the 4-aminonaphthalene-1,8-dicarboximide (ANI) chromophore results in rapid, two-step electron transfer to generate the triradical (D+center dot-C-A(-center dot)-R-center dot). The large through-bond distance between A(-center dot) and R-center dot makes their spin-spin exchange interaction (2J(AR)) negligibly small, whereas their short through-space distance results in a strong dipolar interaction (D-AR), which is observed as a set of broad lines in the TREPR spectra of D+center dot-C-A(-center dot)-R-center dot in solid toluene solution at 85 K. Transient nutation experiments show that these transitions belong to a species with spin S = 1, whereas experiments on D+center dot-C-A(-center dot)-R-center dot in the oriented nematic liquid crystal 4-cyano-4?-n-pentylbiphenyl at 85 K demonstrate the anisotropy of D-AR.