Effect of Synthesis and Crystallization Conditions on the Composition and Structure of Europium(III) Mixed-Carboxylate Benzoate-Pentafluorobenzoate Complexes

In the present work, the influence of the nature of the solvate molecules and N-donor ligands on the structures of the benzoate-pentafluorobenzoate europium complexes was investigated. It was established that the reaction of europium benzoate (bz) and pentafluorobenzoate (pfb) with 1,10-phenanthroline (phen) in acetonitrile in the presence of toluene, o-xylene, or dichloromethane leads to the formation of compounds [Eu(phen)(pfb)(bz)]·4CHCH (I), [Eu(phen)(pfb)(bz)2]·4CH(CH) (II), and [Eu(phen)(pfb) (bz)]·2.898CHCl (III), respectively, which possess similar structures. Using quinoline (quin) as the N-donor ligand, mixed-carboxylate coordination polymer crystals [Eu(H₂O)(pfb)(bz)]2(quin) (IV) were obtained in good yield. The synthesized compounds were characterized by single-crystal X-ray diffraction, IR spectroscopy, and CHN elemental analysis. Non-covalent interactions were analyzed by Hirshfeld surface analysis.