Reaction of Ketenylidenetriphenylphosphorane (Ph₃PCCO) with Platinum(II) and Palladium(II) Complexes. Synthesis, Characterization, and Molecular Structure of [Pt(η³-C₃H₅){η¹-C(PPh₃)(CO)}(PPh₃)]BF₄

Abstract

Ketenylidenetriphenylphosphorane, Ph3P CCO, reacts with Pt(II) and Pd(II) η3-allyl complexes (allyl = C3H5, 2-MeC3H4) to give neutral or cationic mononuclear η1-ketenyl derivatives [M(η3-allyl){(η1-C(PPh3)(CO)}L] m + (L = Cl, m = 0; L = PPh3, m = 1) that have been characterized by elemental analysis, IR, and multinuclear NMR. The X-ray molecular structure determination performed on a single crystal of the air-stable derivative [Pt(η3-C3H5){η1-C(PPh3)(CO)}(PPh3)]BF4 furnishes the first crystallographic evidence of an η1-ketenyl derivative in which the ketene moiety is also involved in an ylide grouping.

Stoichiometric and Catalytic Arene Activations by Platinum Complexes Containing Bidentate Monoanionic Nitrogen-Based Ligands

“…This difference suggests that the indolyl fragment has a greater trans influence than the pyridinyl, a result consistent with the fact that it is the stronger σ-donor . Similar variations in Pt−C bond distances have been observed in other Pt-allyl complexes where distinct trans ligands are present 2 ORTEP diagram of the X-ray crystal structure of (PyInd-F)Pt(η 3 -CH 2 CMeCH 2 ) ( 1b ).…”

One-Pot and Step-by-Step N-Assisted CPh−H Activation in 2-(4-Bromophenyl)imidazol[1,2-a]pyridine: Synthesis of a New C,N-Cyclometalated Compound [{Pt(C∧N)(μ-Cl)}2] as Precursor of Luminescent Platinum(II) Compounds

“…As can be seen, 1 is a mononuclear complex in which the platinum(II) center exhibits a highly distorted square-planar environment mainly due to the geometry and bonding mode of the η 3 -allyl group. The three Pt−C allyl distances are roughly equal and shorter than those found in other η 3 -allyl platinum(II) and palladium(II) complexes containing ligands with a greater trans influence than Cl and N. − The dihedral angle between the best plane defined for the 2-methylallyl moiety and the platinum coordination plane (Pt, Cl, N1, C14, C16) is 73.6(1)°. The Pt−Cl distance [2.368(7) Å] fits the Pt−Cl bond length [2.367(7) Å] found in the relevant complex [(η 3 -C 3 H 5 )Pt(P( t Bu) 3 )Cl]. , The Pt−N bond length [2.092(25) Å] is in the upper range of those observed in Pt(II) complexes with the same kind of ligands, , in agreement with the high trans influence of the η 3 -2-methylallyl group.…”

Ylide Ligands

“…, which only bind to the metal through the heteroatoms, not only in Pd or Pt centers [56,57], but also in other metals [58]. However, highly conjugated ketene ylide [Ph 3 P=C=C=O] coordinates to Pd and Pt metallic centers through the C atom giving derivatives (13) [23,[59][60][61][62][63], which keep the ketene character and react with nucleophiles to give simple ylides (14) (Scheme 6). Another highly conjugated species, the Fehlhammer's ylide, bonds to Pt, Cr or W using the isocyanide functional group, but can also acts as a C,Cbridging ligand, for instance in (15) [64].…”

“…Cl], and finally the methylidyne complex(56).Phosphines, as nucleophiles, add to many unsaturated substrates giving metallated ylides. Scheme 17 collects some representative examples of the addition of phosphines to carbyne complexes, giving(57) [132], to allenylidenes (58)[133], -alkenyls(59)…”