THE JAHN-TELLER EFFECT IN A TRIGONAL BIPYRAMIDAL Ni(III) COMPLEX; SYNTHESIS AND X-RAY CRYSTAL STRUCTURE OF<i>trans</i>-NiI₃(PMe₃)₂

Abstract

Abstract Reaction of [Ni(μ-t-Bu2As)(PMe3)2]2, with I2(Ni:I = 1:2) in toluene yields the black, crystalline Ni(III) complex trans-Nil3(PMe3)2, (1), (38%). The coordination geometry about Ni is a distorted trigonal bipyramid with a distortion which can be attributed to a Jahn-Teller effect. One Ni-I bond (2.530(1)Å) is shorter than the other two (both 2.551(1)Å). Crystal data.(1). C6H18I3NiP2, M = 591.6, orthorhombic, space group Pnma. a = 10.197(3), b = 11.155(8) c = 14.213(3)Å, U = 1616.7(5)Å3, Dc = 2.43 g cm−3, Z = 4. λ(MoK α) = 0.71073 Å (graphite monochromator). μ(MoK α) = 70.4 cm−1. Refinement of 1168 reflection I > 3 ·(I)σ out of 1667 unique observed reflections (2.0° < 2° < 50.0°) gave R and Rw values of 0.046 and 0.066, respectively. The Ni-P distances are 2.246(2) Å and 2.253(2) Å.