title: Syntheses and structures of three complexes of formulas [L3Co(μ2-O2P(Bn)2)3CoL'][L"], featuring octahedral and tetrahedral cobalt(II) geometries; variable-temperature magnetic susceptibility measurement and analysis on [(py)3Co(μ2-O2PBn2)3Co(py)][ClO4].
abstract: The syntheses and structural properties of three dinuclear complexes [L(3)Co(μ(2)-O(2)P(Bn)(2))(3)CoL'][L"] [one ionic L(3) = py(3), L' = py, L" = ClO(4)(-) (1) and two molecular L(3) = py(3), L' = Cl (2) and L(3) = py, μ(2)-NO(3)(-), L' = py (3)] are reported. Complexes feature octahedral Co(II) sites bridged by three dibenzylphosphinate ligands to a tetrahedrally ligated Co(II) site, with the remaining coordination sites occupied by py, nitrato, and Cl ligands. The Co-Co distances are 4.248 Å at 291 K and 4.265 Å at 100 K for 1 and 4.278 and 4.0313(7) Å for 2 and 3, respectively at 100 K. A fit of the low-temperature magnetic susceptibility data was derived for complex 1 with g = 2.25, TIP = 700 × 10(-6) cm(3) mol (-1), λ = -173 cm(-1), κ = 0.93, ν = -3.9, Δ = 630 cm(-1), J = 0.15 cm(-1), and θ = -1.8 resulting in R(χ(M)) = 2.5 × 10(-5) and R(χ(M)T) = 5.8 × 10(-5).
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, USA.
authors.forename: John S
authors.initials: JS
authors.lastname: Maass
authors.forename: Matthias
authors.initials: M
authors.lastname: Zeller
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Breault
authors.forename: Bart M
authors.initials: BM
authors.lastname: Bartlett
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakiyama
authors.forename: Rudy L
authors.initials: RL
authors.lastname: Luck