Dimeric complexes of a tridentate Schiff base ligand - Crystal structure of a Cu-II complex with uncommon mu(2)-N-sulfonamido bridges and ferromagnetic behaviour

摘要

N-[2-(Tosylamino)benzylidene]-2-[(tosylamino)methyl]aniline (H2L) has afforded M-2(II)(L)(2)center dot xMeCN center dot yH(2)O complexes (M = Ni, Pd, Cu, Zn and Cd; x = 0 or 2; y = 0, 4, 6 or 8). Physicochemical characterisation data are indicative of the dinuclear nature of the complexes obtained, where the potential N,N,N-donor L behaves as a dianionic and tridentate ligand. The crystal structure of Cu-2(L)(2)center dot 2MeCN was solved, and it demonstrates that a double mu(2)-N-sulfonamido bridge assembles the neutral Cu-2(L)(2) dimers. This uncommon connection gives rise to a totally planar and nearly square-shaped Cu2N2 metallacycle. The planar geometries around the copper ions undergo a seesaw-shaped distortion, which is probably related to secondary Cu center dot center dot center dot O interactions with neighbouring tosyl groups. This spatial arrangement seems related to the ferromagnetic behaviour shown by the complex.