Two different groups of hemicyanine n-butyltriphenylborate salts (HCBo) were synthesized and examined to verify the possibility of the Marcus equation application for the description of the kinetics of free-radical polymerization photoinitiated via the photoinduced electron-transfer process. The free-energy change (DeltaG(el)) of the electron-transfer process between an excited acceptor and a donor were experimentally determined for 14 new organic photoredox pairs. The relationship between the rate of polymerization and the free-energy change for the electron-transfer process displayed typical Marcus kinetic behavior. The photoreduction of the HCBo produced colorless products. The experimental results indicated that the rate of the light-absorber bleaching process does not compete with the photoinitiation of polymerization. (C) 2003 Wiley Periodicals, Inc.