Syntheses, Structures, and Magnetic Properties of a Family of Heterometallic Heptanuclear [Cu5Ln2] (Ln = Y(III), Lu(III), Dy(III), Ho(III), Er(III), and Yb(III)) Complexes: Observation of SMM behavior for the Dy(III) and Ho(III) Analogues

• Published in: Inorganic chemistry 2013-03, Vol.52 (5), p.2588-2598
• Main Authors: Chandrasekhar, Vadapalli, Dey, Atanu, Das, Sourav, Rouzières, Mathieu, Clérac, Rodolphe
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Copper - chemistry; Lanthanoid Series Elements - chemistry; Magnetic Fields; Material chemistry; Models, Molecular; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic302614k

Sequential reaction of the multisite coordination ligand (LH3) with Cu­(OAc)2·H2O, followed by the addition of a rare-earth(III) nitrate salt in the presence of triethylamine, afforded a series of heterometallic heptanuclear complexes containing a [Cu5Ln2] core {Ln = Y(1), Lu(2), Dy(3), Ho(4), Er(5), and Yb(6)}. Single-crystal X-ray crystallography reveals that all the complexes are dicationic species that crystallize with two nitrate anions to compensate the charge. The heptanuclear aggregates in 1–6 are centrosymmetrical complexes, with a hexagonal-like arrangement of six peripheral metal ions (two rare-earth and four copper) around a central Cu(II) situated on a crystallographic inversion center. An all-oxygen environment is found to be present around the rare-earth metal ions, which adopt a distorted square-antiprismatic geometry. Three different Cu(II) sites are present in the heptanuclear complexes: two possess a distorted octahedral coordination sphere while the remaining one displays a distorted square-pyramidal geometry. Detailed static and dynamic magnetic properties of all the complexes have been studied and revealed the single-molecule magnet behavior of the Dy(III) and Ho(III) derivatives.