Sulfadiazine/dimethylsulfadiazine transition metal complexes: Synthesis, crystal structures and magnetic properties

Sulfadiazine (Hsulf) and dimethylsulfadiazine (Hdmsulf) were used to assemble divalent transition metal complexes (Cu, Ni or Co). Solvated complexes 1–4, dinuclear 1 (Cu2), tetranuclear 2 (Ni4) and 3 (Co4), and two-dimensional polymeric 4, were synthesized by controlling the metal ions, ligands and solvents. For complex 1, two Cu(II) ions are bridged by four NCN groups of four sulf− ligands, while for complex 2, four Ni(II) ions are alternatively bridged by the pyrimidine rings of four sulfadiazine ligands, forming a neutral square Ni4 molecule. In complex 3, four Co(II) ions are bridged by four μ3-OMe− groups, yielding a Co4O4 cubane. Complex 4 possesses a 2D grid structure with the Co(II) ions bridged by the remote amino groups of the ligand dmsulf−. Magnetic susceptibility measurements show that the desolvated complex (1d) exhibits antiferromagnetic coupling between adjacent Cu(II) ions with the 2J value of −90.0 cm−1, and the pyrimidine rings transmit weak antiferromagnetic coupling in complex 2. Complex 3·8H2O shows ferromagnetic coupling via the methoxido bridges with the bridging CoOCo bond angles of 96–99°. Complex 4 displays a magnetic property for mononuclear cobalt(II) complexes due to the remote separation of Co(II) ions.

Four divalent transition metal complexes (Cu, Ni or Co) of sulfadiazine (Hsulf) or dimethylsulfadiazine (Hdmsulf) with polynuclear Cu2, Ni4, Co4 and two-dimensional structures were synthesized by controlling the different metal ions, ligands and solvents. Ferromagnetic interaction between the MeO−-bridged CoII ions was observed, while the pyrimidine bridges transmit antiferromagnetic coupling between CuII or NiII ions.Figure optionsDownload as PowerPoint slide