'Windmill'-shaped LnIII4 (LnIII = Gd and Dy) clusters: magnetocaloric effect and single-molecule-magnet behavior. (4th March 2020)

• Record Type: Journal Article
• Authors: Wang, Wen-Min; Wang, Mei-Jiao; Hao, Sha-Sha; Shen, Qin-Yu; Wang, Mei-Ling; Liu, Qiao-Ling; Guan, Xiao-Fen; Zhang, Xiu-Tang; Wu, Zhi-Lei
• Is Part Of: New journal of chemistry. Volume 44:Number 11(2020)
• Page Start: 4631
• Page End: 4638
• Publication Date: 2020-03-04
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c9nj05317d
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Two 'windmill'-shaped Ln4 clusters (1 and 2 ) have been synthesized. The magnetic study reveals that 1 displays a larger cryogenic magnetocaloric effect, while 2 exhibits SMM behavior. Abstract : Two new tetranuclear lanthanide clusters with the formula [Ln4 (L)4 (μ2 -CH3 O)4 ]·4CH3 OH· x C2 H5 OH (Ln III = Gd (1 ) and Dy (2 ), H2 L = N ′-(4-diethylamino-2-hydroxybenzylidene)-6-(hydroxymethyl)picolinohydrazide, x = 0 for 1 and x = 4 for 2) were assembled by using a polydentate ligand (H2 L) reacting with β-diketonate salts (Ln(acac)3 ·2H2 O, Ln III = Gd (1 ) and Dy (2 )). Single-crystal X-ray structures reveal that clusters 1 and 2 are mainly composed of four Ln III ions that are interconnected through eight μ2 -O bridging oxygen atoms, and the Ln4 clusters show a 'windmill'-shaped arrangement. The magnetic investigations reveal that cluster 1 displays a cryogenic magnetic refrigeration property with a large magnetic entropy (−Δ S m = 29.0 J kg −1 K −1, Δ H = 7.0 T and T = 2.0 K); meanwhile, alternating current (ac) magnetic susceptibility measurement reveals that 2 exhibits typical SMM behavior with a U eff / k B of 42.4 K and pre-exponential factor τ 0 = 1.2 × 10 −6 s.