Laser flash photolysis with magnetic field (MF similar to 0.08 T) has been used to study interaction between Acridine (Acr) and Triethylamine (TEA) in reverse micelles with w(o) = 2.5-40. Dynamic protonation equilibrium exists between (3)Acr and (3)AcrH(+). The intermediates indicate excited-state proton transfer (PT) between (3)AcrH(+) and TEA. However, application of MF highlights the formation of geminate radical ion pairs (RIPs) with triplet spin-correlation, a signature of latent photoinduced electron transfer between (3)AcrH(+) and TEA co-exists with PT. Magnetic field effect (MFE) is prominent for smaller w(o) showing importance of optimum separation between RIP to maximize MFE, whereas PT remains unaltered. (c) 2011 Elsevier B.V. All rights reserved.