Cryogenic magneto-caloric effect and magneto-structural correlations in carboxylate-bridged Gd(III) compounds.

Two new infinite coordination chain compounds [Gd(CH3CO2)(3)(dmf)](infinity) (1) and {[Gd(HO(CH2)(3)CO2)(3)-(H2O)]center dot H2O}(infinity) (2) have been obtained attempting to modify a prototype molecular cooler. The structures of both compounds as determined by single-crystal X-ray diffraction are reported, together with a detailed study of their magnetic and thermal properties, describing for both compounds a large magneto-caloric effect. The dominant ferromagnetic interaction present in 2 clearly favours this material at low applied magnetic fields, with respect to 1 that exhibits antiferromagnetic interactions. Magneto-structural correlations of the sign and strength of the magnetic interactions are derived for carboxylato-bridged Gd(III) systems.