Pyridine Sulfonic Acid Metal Complexes Synthesis And Structural Chemistry

In this thesis, four kinds of substituted pyridine sulfonic acids, 2-hydroxypyridine sulfonic acid, 4-hydroxypyridine sulfonic acid, 2-amidopyridine sulfonic acid and 4-amidopyridine sulfonic acid, have been designed and prepared. Eleven novel complexes with mononuclear, dinuclear, tetranuclear, one-dimensional, two-dimensional as well as supramolecular structures were also synthesized by the self-assemble reactions of 2(4)-hydroxypyridine sulfonic acid with alkali (alkaline earth) ions and 2(4)-amidopyridine sulfonic acid with silver ions. The coordination behaviors and coordination modes of sulfonic groups and metal centers were also studied. The complexes were structurally characterized by elemental analysis, IR, PL and single crystal X-ray diffraction. The four kinds of ligands existed as betaine, and extended to supramolecular networks through H-bonding interactions. The coordination fashions of sulfonic groups can be affected by cooperation of other functional groups. In the former hydroxypyridine sulfonate complexes, sulfonic groups were all engaged in the coordination spheres of metal ions except for Mg(II) ion. Furthermore, high-dimensional complexes can be easily obtained by rational choice of metal centers with large radii. Silver ions in the amidopyridine sulfonate complexes were found to adopt a wide variety of coordination numbers from 2 to 5 and coordination geometries from linear, T-shape, tetrahedron to quadrangular pyramid. Simultaneously, 2-amidopyridine sulfonic acid has potential ability to form layer structures while 4-amidopyridine sulfonic acid was easy to construct chain structures. Luminescent behaviors of metal complexes at room temperature showed that alkali (alkaline earth) metal complexes presented well luminescent emission. However, no clear luminescence was detected for silver complexes, which can be attributed to the heavy atom effect due to the coordination of the ligand to a heavy Ag(I) center.