The chain-shaped coordination polymers based on the bowl-like Ln18Ni24(23.5) clusters exhibiting favorable low-field magnetocaloric effect

• DOI: 10.1016/j.cclet.2021.04.042
• Publication Date: 2021-05-02T00:22:28Z
• Authors: Ningfang Li; Qingfang Lin; Yemin Han; Zeyu Du; Yan Xu
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract The design of assembling high-nuclearity transition-lanthanide (3d-4f) clusters along with excellent magnetocaloric effect (MCE) is one of the most prominent fields but is extremely challenging. Herein, two heterometallic metal coordination polymers are constructed via the “carbonate-template” method, formulated as {[Gd18Ni24(IDA)22(CO3)7(μ3-OH)32(μ2-OH)3(H2O)5Cl]·Cl8·(H2O)14}n and {[Eu18Ni23.5(IDA)22(CO3)7(μ3-OH)32(H2O)5(IN)(CH3COO)2 (NH2CH2COO)Cl]·Cl6·(H2O)17}n [abbreviated as 1-(Gd18Ni24)n and 2-(Eu18Ni23.5)n respectively; H2IDA = iminodiacetic acid; HIN = isonicotinic acid]. Concerning the structures, compounds 1-(Gd18Ni24)n and 2-(Eu18Ni23.5)n both feature the one-dimensional (1D) chain-like structure which is rarely reported in high-nuclearity metal complexes. Meanwhile, the large presences of Gd3+ ions in compound 1-(Gd18Ni24)n are conducive to the fantastic MCE, and the value of −∆Sm is 35.30 J kg−1 K−1 at 3.0 K and ∆H = 7.0 T. And more significantly, compound 1-(Gd18Ni24)n shows the large low-field magnetic entropy change (−∆Sm = 20.95 J kg−1 K−1 at 2.0 K and ∆H = 2.0 T) among the published 3d-4f mixed metal clusters.