EPR spectral determination of electronic substituent effects on the D values of hydrocarbon polyradicals (quintet and septet spin states) composed of localized 1,3-cyclopentanediyl spin-carrying units linked by 1,3-Di- and 1,3,5-trimethylenebenzene ferromagnetic couplers

It has been demonstrated that the D parameter of the tetraradicals and hexaradicals is mainly determined by the spin density of the localized 1,3-cyclopentanediyl spin carrier. Thus the trimethylenebenzene ferromagnetic coupler is essentially negligible.