title: 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.
abstract: 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.
authors: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, India. vc@iitk.ac.in
authors: Vadapalli
authors: V
authors: Chandrasekhar
authors: Atanu
authors: A
authors: Dey
authors: Sourav
authors: S
authors: Das
authors: Mathieu
authors: M
authors: Rouzières
authors: Rodolphe
authors: R
authors: Clérac
mesh_terms: D003300:Copper / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D060526:Magnetic Fields; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; D003300:Copper