Synthesis and reactivity of palladium(II) complexes with the [C(PPh2)3]– ligand. Crystal structures of [Pd(C6F5){(PPh2)2CPPh2}(PPh3)] and [Pd{(PPh2)2CP(O)Ph2}2]·4.74CHCl3

Abstract

Neutral mononuclear complexes of the type [Pd(C₆F₅){(PPh₂)₂CPPh₂}(PR₃)](PR₃= PPh₃1 or PPh₂Et 2) and [Pd{(PPh₂)₂CPPh₂}₂]3 have been obtained by reaction of [Pd(C₆F₅)(acac-O,O′)(PR₃)] or [Pd(acac-O,O′)₂] with HC(PPh₂)₃(Hacac = acetylacetone). The reactions between [Pd(C₆F₅)(acac-O,O′)(tht)](tht = tetrahydrothiophene) or trans-[Pd(C₆F₅)₂(tht)₂] and HC(PPh₂)₃ also renders 3. The complex [Pd{(PPh₂)₂CP(O)Ph₂}₂]4 has been obtained by oxidation of 3 with O₂. Complexes 1–3 which contain the anion [C(PPh₂)₃]^– acting as a P,P′-chelate ligand with one unco-ordinated P atom can be used for the synthesis of neutral or cationic polynuclear derivatives. The structure of these complexes have been established on the bases of IR, ¹⁹F and ³¹P-{¹H} NMR studies. The molecular structures of 1 and 4 have been established by X-ray diffraction methods.