Diphosphoniodiphosphene Formation by Transition Metal Insertion into a Triphosphenium Zwitterion.

Treatment of two equivalents of the triphosphenium zwitterion L with sources of Ni and Pd form the mononuclear η -diphosphoniodiphosphene complexes 1 and 2. The reaction between L and [FeCp(CO) ] results in the binuclear μ-η :η -diphosphoniodiphosphene iron complex 3, which features an alternative bonding motif of the diphosphoniodiphosphene unit. The formation of these species has been confirmed by spectroscopic methods and single-crystal X-ray diffraction analysis, and their electronic structures have been elucidated using computational methods.