Complexation associated rearrangement of iminobiphosphines to diphosphinoamines

The reaction of the iminobiphosphines RN=PPh2-PPh2, where R = C6H4(P-CN), C6H4(m-CN), C6H4(o-C6H5), C6F5 or C6H4(o-CF3) with one molecular equivalent of M(cod)Cl-2 (M = Pd or Pt) results in a rearrangement of the N=P-P unit to the more commonly encountered P-N-P unit, forming mono-chelating complexes of general formula M{RN(PPh2)(2)}Cl-2. The related reaction of the same range of iminobiphosphines with Pt(cod)Cl-2 (but not Pd(cod)Cl-2) in 2:1 ratio affords complexes of general formula [Pt{RN(PPh2)(2)}(2)]2Cl. All 15 complexes are isolated in moderate to high yield and they have been fully characterised by spectroscopic methods. Six complexes, viz. [M{C6H4(p-CN)N(PPh2)(2)}Cl-2], [M{C6H4(m-CN)N(PPh2)(2)}Cl-2] and [M{C6H4(o-C6H5)N(PPh2}(2)) Cl-2] (M = Pd and Pt), have been characterised in the solid state by single crystal X-ray diffraction analysis. (c) 2005 Elsevier B.V. All rights reserved.