INTRINSIC ENHANCEMENT FACTORS OF THE SPIN-ORBIT-COUPLING MECHANISM POLARIZATION IN THE DUROQUINONE-N,N-DIMETHYLANILINE DERIVATIVE SYSTEMS

Dynamics of the electron spin polarization of the quinone anion radica l generated from the photoinduced electron transfer between duroquinon e (DQ) and N,N-dimethylaniline (DMA) as well as its p-halogen substitu ents (4XDMA) has been investigated by using transient absorption and F TEPR spectroscopies. The radical yield decreased with increasing atomi c number of the halogen in the donor. The intrinsic enhancement factor s of net absorptive polarization due to the spin-orbit coupling mechan ism (SOCM) of V-SOCM = 2, 17, and 25 were determined in the unit of th ermal equilibrium polarization at room temperature for the DQ-4ClDMA, DQ-4BrDMA, and DQ-4IDMA systems, respectively. The net absorptive spin polarization observed has been discussed in terms of SOC interaction of the triplet contact radical ion pair (CRIP) state with the ground s tate, which is coupled with the singlet GRIP states in the solvent coo rdinate.