Intrinsic electronic reorganization energy in the electron transfer from substituted N,N-dimethylanilines to phthalimide N-oxyl radical

► The ET reaction from DMA to PINO is studied within a conceptual DFT framework. ► Hardness τAD is related to the DMA/PINO intrinsic electronic reorganization energy, λe.► The vertical electronic energy, ΔEvert, is linearly correlated to τAD namely ΔEvert = 0.872τAD + 4.284; R2 = 0.994, in CH3CN. ► Experimental rate constants are linearly correlated to τAD, i.e., ln kAD = −0.779τAD + 38.364; R2 = 0.980 in CH3CN. ► Substituent effects are rationalized in agreement with experiments.