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) center dot 7H(2)O center dot 6EtOH), complex 4 shows a one-dimensional chain-like structure with formula [EU2(PTMHC)(H2O)(13)] center dot 16H(2)O center dot 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. (c) 2007 Elsevier B.V. All rights reserved.