METAL-COMPLEXES OF 1-OXA-4,7-DITHIACYCLONONANE

The ligand 1-oxa-4,7-dithiacyclononane (L) and its complexes [Pd(L)Cl- 2], [Cu(L)(2)][ClO4]. CH3CN, [Cu(L)Br](2), and [Co(L)(2)][ClO4](2) . 2 CH(3)NO(2) have been prepared, Crystal data are as follows. For monocl inic [Pd(L)Cl-2], C6H12Cl2OPdS2: space group P2(1)/n; a = 8.464(2), b = 12.199(2), c = 10.384(2) Angstrom; beta = 105.09(1)degrees; Z = 4; R = 0.024, R-w = 0.033 for 1721 reflections. For monoclinic [Cu(L)(2)][ ClO4]. CH3CN, C14H27ClCuNO6S4: space group P2(1)/n; a = 7.743(2), b = 19.515(5), c = 15.017(2) Angstrom; beta = 102.85(2)degrees; Z = 4; R = 0.036, R-w = 0.038 for 3124 reflections. For triclinic [Cu(L)Br](2), (C6H12BrCuOS2)(2): space group <P(1)over bar>; a = 7.809(5), b = 8.880 (3), c = 7.567(2) Angstrom; alpha = 92.44(3), beta = 102.85(2), gamma = 99.30(4)degrees; Z = 2; R = 0.027, R-w = 0.027 for 1494 reflections. For monoclinic [Co(L)(2)][ClO4](2) . 2CH(3)NO(2), C14H30Cl2CoN2O14S4: space group P2(1)/c; a = 10.333(3),b = 14.293(6), c = 9.365(4) Angstr om; beta = 100.84(3)degrees, Z = 2; R = 0.067, R-w = 0.058 for 1517 re flections. The ligand displays a variety of conformations in these str uctures. The palladium complex does not undergo 1,4-heteroatom binding site fluxional processes but does dissociate in dimethyl sulfoxide. A n apical Pd ... O (2.968(3) Angstrom) interaction has been detected by both NMR and X-ray studies. The Cu(I) cation is tetrahedral with a [2 +2] mode of ligand coordination. [Cu(L)Br](2) involves two Br bridges between coppers and two thioether sulfurs from a ligand to complete ea ch copper's tetrahedral coordination sphere. Surprisingly, the cyclic voltammetric behavior of the copper complexes is similar to that of 1, 4,7-trithiacyclononane complexes. The cation [Co(L)(2)](2+) is pseudoo ctahedral with nearly regular angles at cobalt but a long (2.235(6) An gstrom) Co-O bond due to Jahn-Teller distortion. The complex [Co(L)(2) ][ClO4](2) is magnetically dilute and low-spin over the temperature ra nge 5-292 K.