Synthesis, Structure, and Physical Properties of Calcium and Strontium Complexes with the Ligand Sulfosalicylic Acid

Two isostructural complexes [Ca(hssal)(H2O)2]n (1) and [Sr(hssal)(H2O)2]n (2) (hssal2– = 5-sulfosalicylate anion) are obtained byusing the ligand 5-sulfosalicylic acid and alkaline earth metal salts under hydrothermal conditions. Their structures were determined by single-crystal X-ray diffraction analysis and further characterized by elemental analyses and IR spectroscopy. Complexes 1 and 2 have a two-dimensional network structure, in which the CaII and SrII ions have an octacoordinate distorted square antiprismatic arrangement. Each sulfosalicylate anion acts as a μ4-bridging ligand, whereas the carboxylate group adopts a chelating coordination. Luminescence properties and thermal stabilities of complexes 1 and 2 were investigated.