title: Reexamination of the magnetic properties of Cu(2)(dca)(4)(2,5-me(2)pyz) [dca = dicyanamide; me(2)pyz = dimethylpyrazine]: isolated spin-1/2 dimers versus long-range magnetic ordering.
abstract: The magnetic properties of Cu(2)(dca)(4)(2,5-me(2)pyz) have been reexamined. The extended structure of Cu(2)(dca)(4)(2,5-me(2)pyz) can be viewed in terms of Cu(2)(2,5-me(2)pyz)(4+) dimer units interconnected via mu(1,5)-dca ligands. The bulk magnetic susceptibility chi(T) and the isothermal M(H) of Cu(2)(dca)(4)(2,5-me(2)pyz) are shown to be well described by an isolated dimer model. This finding was confirmed by carrying out a spin dimer analysis based on tight-binding calculations, which shows that the 2,5-me(2)pyz ligand provides a substantial spin exchange interaction between the Cu(2+) ions while the dca ligands do not.
authors.affiliation: Condensed Matter Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. jmanson@ewu.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Manson
authors.forename: J A
authors.initials: JA
authors.lastname: Schlueter
authors.forename: H-J
authors.initials: HJ
authors.lastname: Koo
authors.forename: M-H
authors.initials: MH
authors.lastname: Whangbo