Structural diversity and fluorescent properties of copper(II) complexes constructed by 5-sulfosalicylate and 2,2′-bipyridine

Two structurally diverse complexes, [Cu4(CH3COO)2(ssal)2(2,2′-bipy)4(H2O)2]6H2O (1) and {[Cu(ssal)(2,2′-bipy)][Cu2(ssal)(2,2′-bipy)2(H2O)2](H2O)}n (2) [ssal = 5-sulfosalicylate trianion; 2,2′-bipy = 2,2′-bipyridine], have been strategically synthesized and characterized by elemental analyses, IR, fluorescent spectra, and single crystal X-ray analyses. The structure of complex 1 is a tetranuclear species where both the carboxyl and phenoxo chelate to the copper atom and the carboxyl also bridges two copper atoms, while complex 2 features a charge transfer species with two cationic and anionic chains, in which both the carboxyl and sulfonyl are coordinated to copper atoms. Fluorescent properties of complexes 1 and 2 suggest interesting potential applications in photoactive materials.