[Co(tn)2ox]Br.H2O, (I), BrCoO5N4C8H22, crystallizes as a race-ate, space group P2(1)/c, with lattice constants a = 12.218(7), b = 7.675(4), c = 15.959(6) angstrom and beta = 95.51(4)-degrees; V = 1489.58 angstrom3 and d(calc; M = 393.13, Z = 4) = 1.753 g CM-3 . A total of 2990 data were collected over the range of 4-degrees less-than-or-equal-to 2theta less-than-or-equal-to 50-degrees; of these, 1576 (independent and with I greater-than-or-equal-to 3sigma(I)) were used in the structural analysis. Data were corrected for absorption (mu = 38.3 cm-1) and the relative transmission coefficients ranged from 0.414 to 0.995. The final R(F) and R(w)F) residuals were, respectively, 0.037 and 0.044. [Co(tn)2oX]I.H2O, (II), ICoO5N4C8H22, crystallizes as a racemate, space group P2(1)/c, with lattice constants a = 10.973I1), b = 7.939(1), c = 17.593(3) angstrom and beta = 97.77(1)-degrees, V = 1518.39 angstrom3 and d(calc; M = 440.13, Z = 4) = 1.925 g cm-3. A total of 2957 data were collected over the range of 4-degrees less-than-or-equal-to 20 less-than-or-equal-to 50-degrees; of these, 2036 (independent and with I greater-than-or-equal-to 3sigma(I)) were used in the structural analysis. Data were corrected for absorption (mu = 31.6 cm-1) and the relative transmission coefficients ranged from 0.555 to 0.999. The final R(F) and R(w)(F) residulas were, respectively, 0.0360 and 0.0528. [Co(tn)2oX]ClO4, (III), CoCl08N4C8H20, crystallizes as a racemate, space group P1BAR with lattice constants a = 7.845(l), b = 9.412(1), c = 10.393(1) angstrom, alpha = 73.06(l), beta = 88.53(1) and gamma = 86.8 5(l)-degrees; V = 732.89 angstrom3 and d(calc; M = 394.66, Z = 2) = 1.788 gCM-3. A total of 3 543 data were collected over the range of 4-degrees less-than-or-equal-to 2theta less-than-or-equal-to 50-degrees; of these, 2859 (independent and with I greater-than-or-equal-to 3sigma(I)) were used in the structural analysis. Data were corrected for absorption (mu = 13.9 cm-1) and the relative transmission coefficients ranged from 0.839 to 0.999. The final R(F) and R(w)(F) residulas were, respectively, 0.0444 and 0.0541. [Co(tn)2ox]Cl.H2O, (IV), CoCl05NC8H22, crystallizes as a racemate, space group P2(1)/n, with lattice constants a = 8.812(3), b = 11.966(4), c = 13.430(3) angstrom and beta = 99.92(2)-degrees; V = 1394.97 angstrom3 and d(calc; M = 348.67, Z = 4) = 1.660g cm-3. Data were collected on two crystals with no success in solving a complete structure (see details in Solution and Refinement of the structures). In structures (I) and (II), both six-membered rings of the cation have the chair conformation, the oxalato ligands are planar; however, the values of the a and c axes have been altered in going from (I) and (II) as a result of the change in halide radius and of a packing difference. In (I), the bromide is hydrogen bonded to -NH2 hydrogens and an oxalato oxygen is bonded to the hydrogens of the water, whereas in (II), the water is bonded to an -NH2 hydrogen of the cation and the iodide is bonded to the water hydrogens. Thus, the scheme of contacts is markedly different in these two species. In (III), one of the rings has the classical chair conformation, the other is a twist-boat. Interestingly, in this cation, the oxalato ligand is not planar, the O-C-C-0 torsion angle being ca 12-degrees.
