NOVEL ORGANIC HIGH-SPIN IONS - THE GENERATION OF THE GROUND-STATE HIGH-SPIN FROM THE FIRST PROTOTYPICAL INTRAMOLECULAR SPIN-FRUSTRATED SYSTEM BY THERMAL ELECTRON-ATTACHMENT

The first prototypical example of intramolecular (through-bond) spin f rustrated systems, 4,4',4 ''-tris (diphenylmethylene)amine, N(p-DPM)(3 ) (S=1) and its mono anion, N(p-DPM)(3), was studied by ESR spectrosco py, emphasizing that the ground-state high-spin (S=3/2) for N(p-DPM)(3 ), was generated in an organic glass, and that quantum nature of elect ron spin alignment in the spin-frustrated systems shows up. The experi mentally determined fine-structure parameters of N(p-DPM)(3) were to b e /D/=0.123cm(-1) and /E/=0.005cm(-1), indicating that an excess elect ron occupies the in-plane nonbonding MO predominantly localized at the divalent carbon site and the molecular structure of N(p-DPM)(3) is no n-C-3 symmetric. The underlying mechanism controlling the spitl alignm ent of the charged high-spin frustrated system is expounded by a VB de scription in terms of an MO calculation.