Dinuclear Nickel(II) complex with a rare Ni( μ ₂-O) ₃Ni core: Crystal structure and magnetic studies

The first triple μ ₂-O-bridged dinuclear Ni(II) complex, [Ni ₂(Flu) ₃](ClO ₄)·(H ₂O) (1, HFlu = 2-(2,4-difluorophenyl)-1,3-bis(1,2,4-triazol-1-yl)-propan-2-ol), has been synthesized and structurally and magnetically characterized. Complex 1 crystallizes in monoclinic, space group P2 ₁/n with a = 12.7143(3), b = 21.3392(6), c = 17.6497(5) Å, β = 106.142(2)°, V = 4599.8(2) Å ³, Z = 4, μ(MoKα) = 0.975 mm ^-1, D _c = 1.662 g/cm ³, GOF = 0.83, the final R (I > 2σ(I)) = 0.0503 and wR (all data) = 0.1288. In 1, three Flu anions encapsulate two nickel(II) ions bridged by three deprotonated μ ₂-O groups. The central alkoxo and terminal triazolyl group chelate one nickel(II) in a six-membered boat configuration. Variable temperature magnetic susceptibilities show an intramolecular anti-ferromagnetic interaction between the Ni(II) ions with J = -26.7(3) cm ^-1.