Tetranuclear lanthanide complexes display significant slow magnetic relaxation with an open hysteresis loop and the magnetocaloric effect

Abstract

Two tetranuclear lanthanide complexes with the formula [Dy4(HL)4(OAc)2(H2O)2]•(Et3NH)2 (1) and [Gd4(HL)4(OAc)2(H2O)2]•(Et3NH)2•(CH3OH)2 (2) (H4L = N, N'-bis(3-hydroxylsalicylidene)benzene-1,2-diamine) were structurally and magnetically characterized. Dynamic magnetic studies shown that complex 1 exhibits two...

Anion-dependent dysprosium(iii) cluster single-molecule magnets

“…The U eff / k value of 116.5 K for 1 is a relatively large value for the Dy 4 cluster SMMs. 14–32 The Cole–Cole diagram also has some characteristics of dual magnetic relaxation (Fig. 4(d)), and the χ′′ versus χ ′ curves could be fitted using a dual-magnetic relaxation formula consisting of the sum of two modified Debye functions, 61,62 yielding α 1 values of 0.189–0.538 and α 2 values of 0.053–0.257 (Table S4, ESI†).…”

“…Dy 4 SMMs have been developed in a series of types such as square, line, cube, butterfly, and diamond, which not only may have high energy barrier values, but also may exhibit multiple magnetic relaxations. 14–32 Among the Dy 6 SMMs, the carbonate-bridged Dy 6 SMMs are particularly important, 33–39 because not only do they exhibit magnetic relaxation behaviour at zero dc field, but also, more importantly, their carbonate ligands can be converted by capturing carbon dioxide from the air during the synthesis reaction directly, which is of great significance in green and low-carbon chemistry. 40,41…”

Dysprosium Clusters from 3-Ethoxysalicylidene Terminal-Decorated Acylhydrazone Ligands: In Situ Ligand Transformation-Assisted Assembly and Zero-Field Single-Molecule Magnet Behaviors

“…From a literature survey, it could be learned that the reported polynuclear Ln-SMMs whose zero field U eff values are over 200 K and/or show magnetic hysteresis behavior are still limited (Table S1), − while in the {Ln 5 }-SMM family, the cases with high SMM performance are even more scarce (Table S11), , among which the highest U eff value is 528 K . Thus, cluster 3 represents not only a new member with high performance in whole polynuclear Ln-SMM species but also the system with the second largest U eff value in the {Ln 5 }-SMM family so far.…”

“…As a kind of novel molecule-based magnetic material that exhibits magnetic remanence under zero applied field, single-molecule magnets (SMMs) have acquired enormous attention owing to their potential applications in various fields including spintronics, quantum information processing, and high density information storage, etc. − With the development of research, the Dy III ion has been increasingly considered as the ideal spin carrier for SMMs because of its large unquenched orbital angular momentum and strong magnetic anisotropy. − By utilizing a symmetry strategy that maximizes the single-ion anisotropy or the synergism between single-ion anisotropy and magnetic interaction, significant performance breakthrough has been achieved in mononuclear and binuclear Dy III -SMMs. − In striking contrast, however, the development of polynuclear Dy-SMMs is still backward. At present, not only their members with high performance are still limited (Table S1), − but also their highest performance parameters are far behind those of mononuclear and binuclear Dy III -SMMs.…”

“…More recently, a {Dy 6 } featuring a circular helicate topology and a quasi-linear {Dy 4 } have been developed. Their highest U eff values reach up to 435 and 353 K, respectively. , Obviously, the special topologies of these Dy III clusters are crucial for the achievement of desirable SMM properties, which suggests that the exploration of Dy III clusters with novel topologies should be a promising avenue toward high SMM performance.…”