Hydrothermal synthesis, crystal structures and properties of Tiron-bridged di- and trinuclear strontium complexes containing nitrogen-donor ligands

The hydrothermal reactions of SrCl2 with 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium (Na2H2Tiron) and 1,10-phenanthroline ligands yielded two strontium complexes of general formula [Sr2(Tiron)2(phen)2(H2O)3]·2H2phen·2H2O (1) and [Sr3(Tiron)2(phen)3(H2O)5]·Hphen·0.5H2phen·8H2O (2) (phen = 1,10-phenanthroline). Complexes 1–2 were characterized by X-ray single crystal diffraction, elemental analyses, FT-IR, and thermogravimetric analyses. Complex 1 feathers a pentdentate Tiron-bridged dinuclear structure, where Sr1 and Sr2 ions exhibit bicapped trigonal prism and monocapped square antiprism geometries, respectively, interconnected through edge-sharing. Complex 2 is a pentdentate and hexadentate Tiron-bridged trinuclear one, where Sr1 and Sr2 ions all exhibit bicapped trigonal prism geometries, interlinked via edge-sharing, and Sr3 ion exhibits a rare triangular prism geometry. The luminescent properties were also studied, and the results exhibit that the luminescence emissions of complexes 1–2 happen the bathochromic shifts, compared with the ligands.

Graphical abstractFor complexes 1–2, the coordination spheres of the strontium ions are O, N-donor atom ones, created by three different types of ligands, exhibiting diversity geometries.Figure optionsDownload full-size imageDownload as PowerPoint slide