From the reaction mixture of 3,6-di-tert-butylcatechol, H-2[L-3,6(cat)], [CrCl3(thf)(3)], and NEt3 in CH3CN in the presence of air, the neutral complex [Cr-III(3,6L center dot(sq))3] (S = 0) (1) was isolated. Reduction of 1 with [Co(Cp)(2)] in CH2Cl2 yielded microcrystals of [Co(Cp)(2)][Cr-III(3,6 L center dot(sq))(2)(L-3,6(cat))] (S = 1/2) (2) where (L-3,L-6 center dot(sq))(1-) is the pi-radical monoanionic o-semiquinonate of the catecholate dianion (L-3,6(cat))(2-). Electrochemistry demonstrated that both species are members of the electron-trarisfer series [Cr(L-3,6(O,O))](z) (z = 0, 1-, 2-, 3-). The corresponding tris(benzo-1,2-dithiolato)chromium complex [N(n-Bu)4][Cr-III(3,5L center dot(S,S))(2)(L-3,5(S,S))] (S = 1/2) (3) has also been isolated; (L-3,5(S,S))(2-) represents the closed-shell dianion 3,5-di-tert-butylbenzene-1,2-dithiolate(2-), and (L-3,L-5 center dot(S,S))(1-) is its monoanionic pi radical. Complex 3 is a member of the electron-transfer series [Cr(L-3,5(S,S))(3)](z) (Z = 0, 1-, 2-, 3-). It is shown by Cr K-edge and S K-edge X-ray absorption, UV-vis, and EPR spectroscopies, as well as X-ray crystallography, of 1 and 3 that the oxidation state of the central Cr ion in each member of both electron-transfer series remains the same (+III) and that all redox processes are ligand-based. These experimental results have been corroborated by broken symmetry density functional theoretical calculations by using the B3LYP functional.