Two series of novel Ln2Mn and Ln6Mn2 (Ln = Gd/Tb) clusters: Synthesis, structures and magnetic properties. (1st November 2020)

• Record Type: Journal Article
• Authors: Chen, Cheng; Yin, Jia-Jia; Zheng, Jun; Zheng, Xiu-Ying
• Is Part Of: Polyhedron. Volume 190(2020)
• Publication Date: 2020-11-01
• Subjects: Ln-Mn -- Clusters -- Mixed ligands -- Magnetic coupling interaction; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2020.114757
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Two series of heterometallic Ln-Mn clusters Ln2 Mn and Ln6 Mn2 were successfully synthesized through mixing ligands, and the magnetic coupling interaction between metals for Gd6 Mn2 were characterized by theoretical calculations. Highlights: High-nuclearity Ln-Mn cluster is one kind of good molecular-based magnetic materials. Magnetic interactions play key role for understanding magneto-structure relationship. Multidentate ligand is beneficial to stabilize Ln-Mn cluster. QMC calculation showed that the mixed magnetic interactions were dominant in Gd6 Mn2 . Abstract: Two linear Ln-Mn(III) clusters were obtained with the formulae of [Gd2 Mn(H2 TEOA)4 (C7 H5 O2 )2 ](NO3 )3 ·4(H2 O) (1 ) and [Tb2 Mn(H2 TEOA)4 (C7 H5 O2 )2 ](C7 H5 O2 )2 (NO3 )·(H3 TEOA)·5(H2 O) (2 ) in the presence of the mixed ligands of triethanolamine (H3 TEOA) and benzoic acid. The multidentate ligand 2, 2-bis(hydroxymethyl)butyric acid (H3 L) and benzoic acid as mixed ligands, two neutral Ln-Mn(III) clusters were prepared with the formulae of [Ln6 Mn2 (L)4 (H2 L)4 (C7 H5 O2 )4 (C2 H5 OH)2 (NO3 )4 (H2 O)4 ]·(CH3 CN)·24(H2 O) (Ln = Gd for 3, Ln = Tb for 4, H3 L = 2, 2-bis(hydroxymethyl)butyric acid). Single X-ray analysis showed that three metal ions of compounds 1 –2 were located on a straight line and eight metal ions of compounds 3 –4 were on a coplanar plane, forming a quadrilateral arrangement. Magnetic data indicated that compounds 1 –4 all exhibited obvious antiferromagnetic properties. The results of Quantum Monte Carlo (QMC) calculation of compound 3 showed that four magnetic coupling interactions of J 1 = –0.401(5) cm −1, J 2 = 0.370(7) cm −1 for Gd⋯Mn and J 3 = −0.498(7) cm −1, J 4 = 0.711(7) cm −1 for Gd⋯Gd were present. The values of −0.401(5) cm −1 for J 1 and −0.498(7) cm −1 for J 3 suggested that the antiferromagnetic coupling interactions of Gd⋯Mn and Gd⋯Gd in the low temperature region were dominant in 3 .