Electron Spin Distributions and g-Value Shifts in the Novel Electron Donors with 1,3-Dithiole Rings

Abstract
The ESR spectra of the cation radicals of TTF and its related compounds in which two 1,3-dithiole rings are connected by conjugated carbon and cumulene chains are measured. The spin distributions obtained from the hfcc due to the protons and sulfur atoms agree well with the results of the MINDO/3 calculations. The spin densities on the sulfur and central carbon atoms decreases as the central chain length increases. A linear relationship, g=2.00379+0.00108 a(S), between the g-values and the sulfur hfcc is noted and explained in terms of the Stone’s theory. The g-values of the cation radicals with cumulene chains deviate from this relation and a possible cause is suggested.