THE RELATIONSHIP BETWEEN THE ELECTRON-AFFINITIES AND HALF-WAVE REDUCTION POTENTIALS OF FULLERENES, AROMATIC-HYDROCARBONS, AND METAL-COMPLEXES

Differences in energy for neutral molecule and negative ions upon goin g from the gas phase to solution, -Delta Delta G(sol), have been calcu lated from gas phase electron affinities and half-wave reduction poten tials for a series of fullerenes, aromatic hydrocarbons, metalloporphy rins, and metal complexes in dimethylformamide (DMF). For those compou nds with similar charge delocalization, the value of -Delta Delta G(so l) is constant and equal to 1.76 +/- 0.06 eV for the fullerenes, 1.99 +/- 0.05 eV for the aromatic hydrocarbons and the metalloporphyrins, a nd 2.19 +/- 0.14 eV for the metal acetylacetonates. The fullerenes for m a new class of molecules in which the charge is highly delocalized, and this is demonstrated by the relatively low value of -Delta Delta G (sol). A procedure for determining adiabatic electron affinities from reduction potentials, and vice versa, is established. This procedure i s applied to benzene to give an electron affinity of -0.7 +/- 0.14 eV, to La@C-82 to give an electron affinity of 3.21 +/- 0.06 eV, and to Y @C-82 to give an electron affinity of 3.32 +/- 0.06 eV. On the other h and, a value of E(1/2) = 0.09 +/- 0.14 V vs SCE is predicted for the r eduction of Ca@C-60 in DMF based upon a reported electron affinity of 3.0 +/- 0.1 eV.