title: Cyanide-bridged [Co(II)2M(II)] and [Co(II)2M(II)2] complexes based on the [Co(II)(triphos)(CN)2] building block: syntheses, structures, magnetic properties, and density functional theoretical studies.
abstract: Two families of cationic cyanide-bridged complexes, namely, {[Co(triphos)(CN)(2)](2)[M(MeOH)(4)]}(ClO(4))(2) ([Co(2)M] M=Mn, Fe, Co, and Ni; triphos=1,1,1-tris((diphenylphosphino)methyl)ethane) and {[Co(triphos)(CN)(2)](2)[M(MeOH)(4)](2)}(ClO(4))(4) ([Co(2)M(2)] M=Mn and Ni) have been prepared from reactions of [Co(II)(triphos)(CN)(2)] and M(ClO(4))(2).6H(2)O (M=Mn, Fe, Co, Ni) in methanol. The trinuclear complexes [Co(2)Mn], [Co(2)Fe], and [Co(2)Co], as well as both new tetranuclear complexes [Co(2)Mn(2)] and [Co(2)Ni(2)], exhibit antiferromagnetic coupling between metal centers. In contrast, the [Co(2)Ni] is characterized by ferromagnetic interactions between the Co(II) and Ni(II) centers. The magnetic behavior for these complexes was investigated by DFT calculations and was found to derive from overlap patterns of the different magnetic orbitals as influenced by the angles of the cyanide bridges.
authors.affiliation: Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, TX 77842-3012, USA.
authors.forename: Ferdi
authors.initials: F
authors.lastname: Karadas
authors.forename: Michael
authors.initials: M
authors.lastname: Shatruk
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Perez
authors.forename: Kim R
authors.initials: KR
authors.lastname: Dunbar