Tris(triphenylphosphine)rhodium cyano and triphenylcyanoborate complexes: Structures and a DFT study

Abstract

The structures of [Rh(CN)(PPh3)3]⋅(EtOH) (1), [Rh(NCBPh3)(PPh3)3] (2), and [Rh(CNBPh3)(PPh3)3] (3) are reported together with a density functional theory (DFT) study of the model compounds [Rh(NCBH3)(PH3)3] and [Rh(CNBH3)(PH3)3]. Compound 1 crystallizes in space group Pc with a = 10.4798(15) A, b = 12.5410(18) A, c = 19.974(3) A and β = 112.215(6)°; compound 2 crystallizes in space group $$P\bar 1$$ with a = 12.929(2) A, b = 14.362(2) A, c = 17.575(3) A and α = 92.544(3)°, β = 90.214(3)°, γ = 113.831(3)°; compound 3 crystallizes in space group $$P\bar 1$$ with a = 12.915(2), b = 14.296(2), c = 17.664(3) A and α = 92.469(3)°, β = 90.088(3)°, γ = 113.768(3)°. All three complexes show slight tetrahedral distortion from ideal square planar geometry (largest for 1). Differences in the reactivity and stability of 2 and 3 are interpreted according to the results of a density functional theory study.