Crystal structures of anti and syn isomers of trans-bis(dimethylphenylphosphine)bis(2-tolyl)nickel(II)

Abstract

The molecular structures of both anti and syn isomers of trans-bis(dimethylphenlylphosphine)bis(2-tolyl)nickel(II), trans-[Ni(C 6H 4Me-2) 2(PMe 2Ph) 2] have been determined by single-crystal X-ray diffraction studies. Crystals of the anti isomer are monoclinic, space group P2 1/ n with Z = 2 in a unit cell of dimensions, a 12.288(3), b 7.345(2), c 15.930(3) Å, β 103.49(2)°, where the molecule has a centrosymmetric structure. Crystals of the syn isomer are monoclinic, space group P2 1 with Z = 4 in a unit cell of dimensions, a 9.492(2), b 17.540(4), c 16.825(3) Å, β 94.77(2)°, where two crystallographically independent molecules exist. Structures were refined to R = 0.036 (2581 reflections) and R = 0.079 (4056 reflections) for the anti and syn isomers, respectively. The coordination geometry around the Ni atom is typically square-planar in each complex. All the structural parameters, including the NiC(2-tolyl) bond lengths, are normal when compared with those hitherto reported. The non-bonded distances between two adjacent methyl carbon atoms of 2-tolyl groups are not less than 3.9 Å in the syn isomer.