Crystal Structure of [Co2(μ-dmg)2(μ-dmg H)(dmg H)(Pø3)] 1/2 dmg H2 · 1/2 CH3OH: A Crystal Containing Various Forms of dmg Ligand

The crystal structure of Co₂(μ-dmg)₂(μ-dmg H)(dmg H)(Pø₃)] · 1/2 dmg H₂ · 1/2 CH₃OH has been determined by single crystal X-ray diffraction. The title complex crystallizes in triclinic space group P&1bar; with a=10.859(3), b=13.299(3), c=15.247(3)Å, α=98.52(2), β=99.26(2), γ=97.80(2)° and Z=2. The agreement indices are R(F)=0.062 and R_w(F)=0.085 for 5231 observations and 515 variables. Both cobalt atoms have an oxidation state of 3+ and are both six-coordinated; one Co(III) atom is bonded to a phosphorous atom of triphenylphosphine, four nitrogen atoms of two planar ligands, dmg^2? and dmgH^?, and one oxygen atom of another dmg^2? ligand. The other Co(III) atom is coordinated by four nitrogen atoms of two cis nonplanar ligands, dmg^2?, dmgH^?, and two oxygen atoms of the other dmg^2? and dmgH^? ligands. There are three N-O bridged ligands namely two dmg^2? and one dmgH^? between two Co(III) atoms. A free molecule of dmgH₂ and a molecule of CH₃OH are also found in the crystal lattice. The structure interestingly demonstrates the possible various forms of dmg, not only on their charge but also in different conformations upon coordination.