Two Ln4 clusters based complexes exhibiting magnetocaloric effect and magnetic dynamics behaviors

Two new tetranuclear Ln-based clusters, namely [Ln(4)(mu(3)-OH)(2)L-6(beaC)(4)] (Ln = Gd (1) and Dy (2)), were successfully assembled by employing 5-(2-thenylidene)-8-hydroxylquinoline (HL) and 1-benzoylacetone (Hbeac). They were structurally characterized by single crystal X-ray diffraction. In 1.Gd and 2.Dy, the structures of them are very similar with planar [Ln(4)O(2)] cluster at the center, four Ln(III) ions in which are further coordinated by six L- and four beac(-) anions in the modes of mu(2)-eta(2)eta(1) for L- and mu(2)-eta(2)eta(1) for beac(-), respectively. Additionally, the magnetic measurement of them reveal that 1.Gd displays magnetic entropy change (-Delta S-m) of 21.55(3) J K-1 kg(-1) at 2 K for Delta H = 7 T. For 2.Dy, it exhibits slow magnetic relaxation behavior with the energy barrier (Delta E/k(B)) of 27.96(7) K. (C) 2018 Elsevier Ltd. All rights reserved.