Four members of the rhenium tris(dithiolene) electron transfer series have been prepared, [Re(S2C2R2)(3)](z) {R = Ph, z = 1+ (1), 0 (2), 1-(3); R = CN, z = 2- (4)}, with the anions in 3 and 4 structurally characterized. The intraligand C-S and C-C bond lengths for 3 vs 2 are indicative of ligand reduction concomitant with an overall distorted trigonal prismatic geometry (Theta = 26.3 degrees cf. 3.8 degrees in 2). The distorted octahedral ReS6 polyhedron in 4 (Theta = 38.3 degrees) indicates reduction of the metal to a Re(IV) d(3) central ion. This series has been probed by sulfur K-edge X-ray absorption spectroscopy (XAS), and the electronic structures are unambiguously defined as follows: [Re-V(L-3(4-))](1+) (S = 0) for the monocation in 1; [Re-V(L-3(5-center dot))](0) (S = 1/2) for neutral 2; [Re-V(L-3(6-))](1-) (S = 0) for the monoanion in 3; and [Re-IV(L-3(6-))](2-) (S = 1/2) for the dianion in 4. The sulfur 3p character in the frontier orbitals-the covalency-is estimated by two different approaches. Method A utilizes the radial dipole integral (I-s) derived from the S 1s -> 4p transition, whereas method B, involves time-dependent density functional theoretical (TD-DFT) calculation of the pre-edge transitions and calibrated to the intensity in [Re(pdt)(3)] (pdt(2-) = 1,2-diphenyl-1,2-dithiolate). The two estimates are contrasted for the rhenium series and extended to the [V(pdt)(3)](0/1-), and [Mo(mdt)(3)](0/1-/2-) (mdt(2-) = 1,2-dimethyl-1,2-dithiolate) series, ultimately providing a refined description of the contested electronic structure of neutral molybdenum (and tungsten) tris(dithiolenes) compounds.