A simple route to dinuclear complexes containing unusual μ-Nsulfonamido bridges

We report here the straightforward synthesis of some dimeric transition metal complexes of three Schiff base ligands, which were obtained by condensation of 2-tosylaminomethylaniline with 2,3-dihydroxybenzaldehyde (H2L1), 2,4-dihydroxybenzaldehyde (H2L2), and 4-formyl-3-hydroxybenzoic acid (H2L3), respectively. Both ligands and complexes were characterized by a combination of 1H NMR, infrared and mass spectrometries, and elemental analyses. Furthermore, the crystal structures of H2L2 and Pd2L22·2MeOH were elucidated by X-ray diffraction. The crystal structure of Pd2L22·2MeOH has instead of typical μ-Ophenoxo bridges, repeating units held together by unusual μ-Nsulfonamido bridges. This complex is chiral, although it crystallizes as a racemate, with C2v symmetry, where the two bridging nitrogens are asymmetric centers with identical handedness.