Synthesis, crystal structure and magnetic behaviour of dimeric and polymeric gadolinium carboxylates with pentafluoropropionic acid

The three novel gadolinium(III) containing compounds (NH3CH3)[Gd(CF3CF2COO)4(H2O)] (1), (NH3C2H5)[Gd(CF3CF2COO)4(H2O)] (2) and ((CH3)4N)[Gd(CF3CF2COO)3(H2O)2]CF3CF2COO (3) were synthesized and structurally characterized by X-ray crystallography. In the crystal structures of 1 and 2, the gadolinium ions are bridged by carboxylate groups to dimers with a Gd3+–Gd3+ distance of 451.6(2) (1) and 451.8(3) pm (2), respectively. In the crystal structure of 3 the Gd3+ ions are bridged by carboxylate groups to chains with almost the same Gd3+–Gd3+ distances (494.0(8) and 503.4(7) pm). The magnetic behaviour of 1 and 2 was investigated in the temperature range of 1.76–300 K. The magnetic data indicate weak antiferromagnetic interactions within the dimeric unit.