Synthesis, Structures, and Magnetic Properties of Binuclear [CrLn] (Ln = Gd or Dy) and Trinuclear [Cr2Ln] (Ln = Gd, Dy, or Tb) Heterometallic Clusters with 2,2′-Bipyridine as Ligand

• Published in: European journal of inorganic chemistry Vol. 2015; no. 34; pp. 5702 - 5707
• Main Authors: Li, Zhong-Yi, Wang, Xiao-Qun, Zhang, Jian-Jun, Liu, Shu-Qin, Ni, Jun, Sun, Ying-Ji
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2015; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Antiferromagnetism; Chromium; Cluster compounds; Clusters; Dysprosium; Equivalence; Heterometallic complexes; Lanthanides; Ligands; Magnetic properties; Magnetism; Perchlorates
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.201500786

The syntheses, structures, and magnetic properties of two series of Cr–Ln heterometallic clusters based on the 2,2′‐bipyridine (bipy) ligand are reported; binuclear [LnCr(bipy)2(μ2‐OH)2(H2O)6](ClO4)4·2H2O {Ln = Gd (1Gd) or Dy (1Dy)} and trinuclear [LnCr2(bipy)4(μ2‐OH)4(H2O)4](ClO4)5·H2O {Ln = Gd (2Gd), Dy (2Dy), or Tb (2Tb)}. Their syntheses could be controlled by the amount of lanthanide perchlorate used. The binuclear [CrLn] clusters could be formed with 24 equivalents of Ln(ClO4)3, whereas 12 equivalents of Ln(ClO4)3 gave the trinuclear [Cr2Ln] species with a CrLnCr core. The Cr3+ and Ln3+ ions are bridged by μ2‐OH groups in the two systems, and the [Cr2Ln] cluster is further assembled into a 1D supramolecular architecture by weak intermolecular π–π interactions. Magnetic analyses reveal that the Cr···Gd interactions in 1Gd and 2Gd are both antiferromagnetic. Oxygen‐bridged binuclear [LnCr] and trinuclear [LnCr2] heterometallic clusters with 2,2′‐bipyridine (bipy) ligands were prepared by a stepwise synthetic procedure, which could be controlled by the amount of lanthanide perchlorate used. The Cr···Gd interactions in [GdCr(bipy)2(μ2‐OH)2(H2O)6](ClO4)4·2H2O and [GdCr2(bipy)4(μ2‐OH)4(H2O)4](ClO4)5·H2O are both antiferromagnetic.