Synthesis and crystal structure of an indenylnickel(II) NHC complex (Ind)NiBr(1,3-bisbenzylimidazol-2-ylidene)

Abstract

The complex (Ind)NiBr(1,3-bisbenzylimidazol-2-ylidene) (Ind = indenyl) 1 has been prepared in ca. 65% yield via the reaction of (Ind)2Ni with an equivalent of 1,3-bis-benzylimidazolium bromide in THF/CH2Cl 2 at 45°C, supported by elemental analysis, NMR spectroscopy and X-ray crystal determination. The crystal belongs to the triclinic system, space group P1 with a = 7.072(1), b = 11.264(2), c = 14.541(3) Å, α = 102.21(3), β = 93.44(3), γ = 90.81(3)°, V = 1129.7(4) Å3, Z = 2, Mr = 502.08, Dc = 1.476 g/cm3, F(000) = 512, μ = 2.642 mm-1, R = 0.0490 and wR = 0.1137 for 3913 observed reflections (I > 2σ(I)). The center nickel atom is coordinated by a bromide ligand, a carbene carbon and three carbon atoms of the five-membered indenyl group to form either a highly distorted square pyramid or a highly distorted square plane.