Molecular assemblies of trichloride neodymium and europium complexes chelated by 1,10-phenanthroline

Four trichloride lanthanide (neodymium or europium) complexes (1–4) have been solvothermally synthesized with the 1,10-phenanthroline (phen) chelate in ethanol solvent and their structures have been characterized by single-crystal X-ray diffraction analysis. Depending on the Ln/phen ratio, different motif nuclearities have been observed. With Ln/phen = 1/2, a dinuclear species with μ2-Cl2 edge-sharing bridge is formed with neodymium, NdCl3(phen)2 (1), whereas a mononuclear complex appears with europium, EuCl3(phen)2 (4) with an unusual pentagonal bipyramid for the lanthanide center (coordination 7). When Ln/phen ratio increases (1/1), an identical complex is obtained with Nd (2) or Eu (3). It is a monohydrated complex LnCl3(H2O)(phen)2 with one water molecule completing the coordination sphere of the lanthanide. For all compounds, each rare-earth cation is chelated by two distinct phen ligands. Thermal behavior of complexes 1 and 2 are discussed (by means of thermogravimetric analysis and X-ray thermodiffraction) as well as the luminescence spectra of europium-based complexes 3 and 4 (Supplementary Material).

A series of trichloride neodymium or europium complexes has been solvothermally synthesized in ethanol and structurally characterized. Anhydrous dinuclear NdCl3(phen)2 or mononuclear EuCl3(phen)2 species have been isolated with a Ln/phen ratio of 1/2, whereas monohydrated mononuclear LnCl3(H2O)(phen)2 forms crystallized from Ln/phen ratio of 1/1.Figure optionsDownload as PowerPoint slideHighlights
► Solvothermal syntheses of dinuclear and mononuclear Nd- or Eu-trichloro complexes.
► Single-crystal X-ray diffraction structural determination.
► Thermogravimetric and X-ray thermodiffraction analyses.
► Luminescence spectra of the Eu(III) complex.