An unprecedented decanuclear Gd(III) cluster composed of the [Gd10(μ3-OH)8](22+) core has been hydrothermally synthesized. Magnetic analyses indicate that this complex shows weak antiferromagnetic behavior with a relatively large magnetocaloric effect (-ΔS(m)(max) = 31.22 J kg(-1) K(-1)).

Two series of lanthanide metal–organic frameworks, [Ln(FDA)(OX)0.5(H2O)2]·(H2O) (1Ln) (Ln = Pr 1, Nd 2, Eu 3, Gd 4, Tb 5), [Ln(FDA)(OX)0.5(H2O)2]·(H2O) (2Ln) (Ln = Sm 6, Tb 7, Dy 8, Ho 9, Yb 10) (OX = oxalate), have been prepared by reacting Ln(NO3)3·6H2O with furan-2,5-dicarboxylic acid (H2FDA) at different temperatures under hydrothermal conditions. All the complexes are characterized by elemental analysis, IR, X-ray powder diffraction, and single-crystal X-ray diffraction. Structure analyses show that 1Ln and 2Ln are supramolecular isomerisms. 1Ln possesses a three-dimensional network with monoclinic space group P21/c, whereas 2Ln exhibits a three-dimensional framework with monoclinic space group C2/c. The distinct architectures of these two series of ten complexes indicated that the reaction temperature plays an important role in the formation of such coordination structures. Meanwhile, the photoluminescent properties of 4, 5, 7, and 8 are also investigated in the solid state at room temperature.

Hydrothermal synthesis of Gd 2 O 3 and iminodiacetic acid (H 2 IDA) yields a three-dimensional (3D) complex {[Gd 2 (IDA) 3 ]• 2H 2 O} n (1) including Gd 16 macrocycles. Magnetic investigation indicates the presence of weak antiferromagnetic interaction between Gd III ions and a large magnetocaloric effect with −ΔS m max = 40.6 J kg −1 K −1 .

Four carboxylate-bridged Gd(III) complexes (1-4) with 1D/2D structures have been synthesized by using the hydrothermal reaction of Gd2O3 with various carboxylate ligands. Compounds 1 and 2 contained the same [2n] Gd(III)-OH ladders, but with different crystallographically independent Gd(III) ions, whilst the structures of compounds 3 and 4 were composed of [Gd4(μ3-OH)2(piv)8(H2O)2](2+) units and 1D ladder Gd(III) chains, respectively. Antiferromagnetic interactions occurred in compounds 1-3, owing to their small Gd-O-Gd angles, whereas ferromagnetic coupling occurred in compound 4, in which the Gd-O-Gd angles were larger. These complexes exhibited a distinct magnetocaloric effect (MCE), which was affected by their different magnetic densities and exchange interactions. Among these compounds, complex 4 presented the largest MCE (-ΔS(m)(max)=43.6 J kg(-1) K(-1)), the lowest M(w)/N(Gd) ratio (the highest magnetic density), and weak ferromagnetic coupling. Therefore, a lower M(w)/N(Gd) ratio and weaker exchange interactions (a smaller absolute value of θ) between Gd(III) ions resulted in a larger MCE for the Gd(III) complexes.