Europium (III) complexes derived from carboxylic-substituted polychlorotriphenylmethyl radicals

Two europium (III) complexes (3 and 4) have been obtained reacting europium (III) nitrate and two polychlorotriphenylmethyl radicals properly functionalized with one (PTMMC−, 1) and six (PTMHC6−, 2) carboxylate groups, respectively. While complex 3 reveals a lamellar polar–apolar separated ion pair structure alternating PTM-based bilayers with nonaaquaeuropium cations ([Eu(H2O)9](PTMMC)3(PTMMCH)3 · 7H2O · 6EtOH), complex 4 shows a one-dimensional chain-like structure with formula [Eu2(PTMHC)(H2O)13] · 16H2O · EtOH. Magnetic properties of both complexes were studied in the 2–300 K range, and show the presence of weak inter-radical antiferromagnetic interactions below 5 K.

Graphical abstractTwo europium (III) complexes were obtained by reacting polychlorotriphenylmethyl (PTM) radicals functionalized with one and six carboxylate groups with europium (III) nitrate. The compound obtained with the mono-carboxylate ligand shows a polar–apolar lamellar crystal structure, whereas the complex with the hexa-carboxylate radical has a one-dimensional polymeric structure. The magnetic properties of both complexes were studied, and reveal the presence of weak inter-radical antiferromagnetic interactions at low temperatures.Figure optionsDownload full-size imageDownload as PowerPoint slide