37017-94-0

Upstream product

• 220282-70-2 dichlorobis(diphenylphosphine)palladium(II) 
• 829-85-6 diphenylphosphane 
• 149184-57-6 tris-di-tert-butylphosphine palladium⁽⁰⁾ 

Relevant academic research and scientific papers

Synthesis of diphenylphosphine palladium complexes

The synthesis of Pd(PPh2H)2Cl2 is achieved by reaction of Pd(PhCN)2Cl2 with PPh2H in toluene at room temperature. Pd(PPh2H)2Cl2 spontaneously transforms int

New dinuclear diphenylphosphido-bridged palladium(I) derivatives and the X-ray crystal and molecular structures of the mononuclear homoleptic diphenylphosphine complexes Pd(PPh2H)4 and [Pd(PPh2H)4](BF4)2

By reacting CpPd(η3-C3H5) with PPh2H we isolated the doubly bridged dinuclear complex [Pd2(μ-PPh2)2(PPh2H)3] (1). This reacts with HBF4 yielding the mono-phosphido-bridged cationic derivative [Pd2(μ-PPh2)(PPh2H)4]BF4 (2)BF4, arising from the protonation of one of the bridging phosphides. Contrary to our previous data on the parent t-butyl systems, a mononuclear homoleptic phosphine complex is not an intermediate in the formation of 1. Pd(PPh2H)4 (3), was in fact prepared by an independent route and was shown to decompose thermally to another (uncharacterized) polynuclear derivative; fluoboric acid reacts with 3 yielding its palladium(II) analogue [Pd(PPh2H)4](BF4)2 (3)(BF4)2, with dihydrogen evolution. We also report the crystal and molecular structures of 3 and (3)(BF4)2, the first homoleptic transition metal complexes of diphenylphosphine to be structurally characterized.

Donor-free phosphenium-metal(0)-halides with unsymmetrically bridging phosphenium ligands

Reactions of (cod)MCl2 (cod = 1,5 cyclooctadiene, M = Pd, Pt) with N-heterocyclic secondary phosphines or diphosphines produced complexes [(NHP)MCl]2 (NHP = N-heterocyclic phosphenium). The Pd complex was also accessible from a chlorophosphine precursor and Pd2(dba) 3. Single-crystal X-ray diffraction studies established the presence of dinuclear complexes that contain μ-bridging NHP ligands in an unsymmetrical binding mode and display a surprising change in metal coordination geometry from distorted trigonal (M = Pd) to T-shaped (M = Pt). DFT calculations on model compounds reproduced these structural features for the Pt complex but predicted an unusual C2v-symmetric molecular structure with two different metal coordination environments for the Pd species. The deviation between this structure and the actual centrosymmetric geometry is accounted for by the prediction of a flat energy hypersurface, which permits large distortions in the orientation of the NHP ligands at very low energetic cost. The DFT results and spectroscopic studies suggest that the title compounds should be described as phosphenium-metal(0)-halides rather than conventional phosphido complexes of divalent metal cations and indicate that the NHP ligands receive net charge donation from the metals but retain a distinct cationic character. The unsymmetric NHP binding mode is associated with an unequal distribution of σ-donor/π-acceptor contributions in the two M-P bonds. Preliminary studies indicate that reactions of the Pd complex with phosphine donors provide a viable source of ligand-stabilized, zerovalent metal atoms and metal(0)-halide fragments.