title: Strong Direct Magnetic Coupling in a Dinuclear Co(II) Tetrazine Radical Single-Molecule Magnet.
abstract: The ligand-centered radical complex [(CoTPMA)2 -μ-bmtz(.-) ](O3 SCF3 )3 ⋅CH3 CN (bmtz=3,6-bis(2'-pyrimidyl)-1,2,4,5-tetrazine, TPMA=tris-(2-pyridylmethyl)amine) has been synthesized from the neutral bmtz precursor. Single-crystal X-ray diffraction studies have confirmed the presence of the ligand-centered radical. The Co(II) complex exhibits slow paramagnetic relaxation in an applied DC field with a barrier to spin reversal of 39 K. This behavior is a result of strong antiferromagnetic metal-radical coupling combined with positive axial and strong rhombic anisotropic contributions from the Co(II) ions.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, TX 77842 (USA) http://www.chem.tamu.edu/rgroup/dunbar/
authors.forename: Toby J
authors.initials: TJ
authors.lastname: Woods
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, TX 77842 (USA) http://www.chem.tamu.edu/rgroup/dunbar/
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Ballesteros-Rivas
authors.affiliation: Institute of Applied Physics, Academy of Sciences of Moldova, Academy str. 5, Kishinev, MD 2028 (Moldova).
authors.forename: Sergei M
authors.initials: SM
authors.lastname: Ostrovsky
authors.affiliation: Institute of Applied Physics, Academy of Sciences of Moldova, Academy str. 5, Kishinev, MD 2028 (Moldova).
authors.forename: Andrew V
authors.initials: AV
authors.lastname: Palii
authors.affiliation: Institute of Applied Physics, Academy of Sciences of Moldova, Academy str. 5, Kishinev, MD 2028 (Moldova).
authors.forename: Oleg S
authors.initials: OS
authors.lastname: Reu
authors.affiliation: Institute of Applied Physics, Academy of Sciences of Moldova, Academy str. 5, Kishinev, MD 2028 (Moldova).
authors.forename: Sophia I
authors.initials: SI
authors.lastname: Klokishner
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, TX 77842 (USA) http://www.chem.tamu.edu/rgroup/dunbar/. dunbar@chem.tamu.edu.
authors.forename: Kim R
authors.initials: KR
authors.lastname: Dunbar
keywords: cobalt; dinuclear single molecule magnet; magnetic exchange coupling; radicals; tetrazine