Crystals of compound (I) and (II) are black in reflected light and brown‐ black in transmitted light. The 1H-nmr of the cations of (I), recorded in D6-DMSO, show peaks, relative to the 1H of D6-DMSO, at + 0.46 ppm(rel. int. = 3); + 0.85 ppm(rel. int. = 1.2); + 1.80 ppm (rel. int. = 3); and −4.18 ppm(rel. int. = 1). The magnetic susceptibility of (I) is C′m (293.18 K) = 588.45×10−6 c.g.s. units, which corresponds to a m eff = 0.295 B.M. per Co ion; however, the small shifts and sharp 1H-nmr lines in the DMSO spectrum preclude the presence of paramagnetic clusters. Cyclic voltametry of the cation present in (I) shows highly distorted, irreversible, oxidation and reduction waves which indicate the lack of stability of any oxidized or reduced form ‐ a fact which accords with the sharp lines of the NMR spectra; e.g., no stable paramagnetic species are present in (I). Compound (I), M.W. = 941.24, crystallizes in P21/n (No. 14), with cell constants a = 11.789(2), b = 13.855(2), c = 21.534(3) Å, β = 91.94(1)° V = 3515.44 Å 3, d (meas; z = 4) = 1.778 gm-cm−3. A total of 4705 data were collected in the range 4° ≤ 2θ ≤ 50°. They were corrected for absorption (μ = 19.562 cm−1; rel. trans. coeff. range = 0.8642 to 0.9997); of these, 2623 were unique and had l ≥ 3σ(l). The structure was solved by direct methods, none of the hydrogens of the amine ligands were found experimentally at sensible positions; thus, they were left out. Refinement of the heavy atoms (anisotropic) led to final residuals of R(F) = 0.0637 and 0.0771. Compound (II), M.W. = 950.20, crystallizes in space group P1 (bar; No. 2), with cell constants a = 12.858(3), b = 12.475(2), c = 12.114(2) Å, α = 96.63(1), β = 91.94(1) and γ = 61.71(2)° V = 1615.68 Å 3, d(meas; z = 2) = 1.953 gm-cm−3. A total of 5657 data were collected in the range 4° ≤ 2θ ≤ 50°. They were corrected for absorption (μ = 21.301 cm−1; rel. trans. coeff. range = 0.7372 to 0.9998); of these, 4456 were unique and had l ≥ 3σ (l). The structure was solved by direct methods, the majority of the hydrogens of the amine ligands were found experimentally at sensible positions, the rest were calculated at idealized positions (N═H = 0.95 Å). The hydrogens of the OH ligands were located experimentally in a final difference Fourier map. Refinement of the heavy atoms (anisotropic) with fixed hydrogens (B = 5.00 A˚ 2) led to final residuals of R(F) = 0.0348 and 0.0440. Precisely as visualized by Werner, the hexol cations consist of a central Co(III) cation surrounded by three {Co(NH3)4(OH)2]1+ ligands. IN (I), the O═Col═O angles are acute (av. value = 82.97°), as expected from the electrostatic repulsion of the Co(III) central cation and the monopositive ligands surrounding it. Consequently, the Co… Co distances the long (2.896, 2.888 and 2.889 A˚) and the the av. Co═O═Co angles are 97.43°. The remaining portions of the cation and anions are as expected from standard values; i.e., Co═O═1.90–1.95 and Co═N = 1.95–2.00 A˚. In (II), the Col═O═Co angles are also obtuse (av. value = 97.87°), as expected from the electrostatic repulsion of the Co(III) central cation, and the Co… Co distances are equally long (2.881, 2.876 and 2.874 A˚; on average, 2.877 A˚).