The electronic structures of complexes of iron containing two S,S'-coordinated benzene-1,2-dithiolate, (L)(2-), or 3,5-di-tert-butyl-1,2-benzenedithiolate, (L-Bu)(2-), ligands have been elucidated in depth by electronic absorption, infrared, X-band EPR, and Mossbauer spectroscopies. It is conclusively shown that, in contrast to earlier reports, high-valent iron(IV) (d(4), S = 1) is not accessible in this chemistry. Instead, the S,S'-coordinated radical monoanions (L-center dot)(1-) and/or (L-Bu center dot)(1-) prevail. Thus, five-coordinate [Fe(L)(2)(PMe3)] has an electronic structure which is best described as [Fe-III] (L)(L-center dot)(PMe3)] where the observed triplet ground state of the molecule is attained via intramolecular, strong antiferromagnetic spin coupling between an intermediate spin ferric ion (S-Fe = 3/2) and a ligand radical (L-center dot)(1-) (S-rad = 1/2). The following complexes containing only benzene-1 2-dithiolate(2-) ligands have been synthesized, and their electronic structures have been studied in detail: [NH(C2H5)(3)](2)[Fe-II](L)(2)] (1), [N(n-Bu)(4)](2)[Fe-2(III)(L)(4)] (2), [N(n-Bu)(4)](2)[Fe-2(III)(L-Bu)(4)] (3); [P(CH3)Ph-3][Fe-III(L)(2)(t-Bu-py)] (4) where t-Bu-py is 4-tert-butylpyridine. Complexes containing an Fe-2(III))(L-center dot)-or Fe-III(L-Bu)(L-Bu center dot)-moiety are [N(n-Bu)(4)][FeIII2(L-Bu center dot)(3)](3(ox)), [Fe-III(L)(L-center dot)(t-Bu-py)] (4(ox)), [Fe-III(L-Bu)(L-Bu center dot)-(PMe3)] (7), [Fe-III(L-Bu) (L-Bu center dot)(PMe3)(2)] (8), and [Fe-III(L-Bu)(L-Bu center dot)(PPr3)] (9), where Pr represents the n-propyl substituent. Complexes 2, 3(ox), 4, [Fe-III(L)(L-center dot)PMe3)(2)] (6), and 9 have been structurally characterized by X-ray crystallography.