Magnetic properties and sensitized visible and NIR luminescence of Dy<sup>III</sup> and Eu<sup>III</sup> coordination polymers by energy transfer antenna ligands
<p>Two coordination polymers, {[Ln(2-stp)(4,4′-bipy)(H<sub>2</sub>O)].(H<sub>2</sub>O)}, [Ln = Dy (<b>1</b>) and Eu (<b>2</b>), 2-stp = 2-sulfoterephthalate and 4,4′-bipy = 4,4′-bipyridine] have been characterized by solid state UV-vis, FTIR spectra, X-ray single crystal diffraction and solid state photoluminescence. Variable-temperature magnetic susceptibility and isothermal magnetization as function of external magnetic field is also studied for both complexes. After ligand-mediated excitation, both complexes show the characteristic visible and NIR luminescence of the corresponding Ln<sup>III</sup> ions (Ln = Dy, Eu) which is due to efficient energy transfer from the ligands to the central Ln<sup>III</sup> ions <i>via</i> an antenna effect. The indirect energy transfer in both complexes has been investigated and discussed in detail.</p
