Synthesis, X-Ray Crystal Structure and Reactivity of [(tmeda)(p-tolyl)Pd(μ2-I)AgL], an Unusual Silver Iodide Complex; Reversible CO Insertion into the Pd-C Bond of [Pd(PPh3)(p-tolyl)L] (L– = [(C5H5)Co{P(OR)2O}3]–, R = Me, Pri)

Abstract

The palladium complexes [Pd(PPh₃)(aryl)L_OR] (aryl = Ph, p-tolyl; L_OR¯ = [(C₅H₅)Co{P(OR)₂O}₃]¯, R = Me, Prⁱ) have been prepared by reaction of [PdI(aryl)(tmeda)] (tmeda = N,N,N′,N′-tetramethyl-ethylenediamine) with the silver salts AgL_OR in the presence of PPh₃. The complexes [Pd(PPh₃)(aryl)L_OR] rapidly and reversibly insert carbon monoxide to yield the aroyl palladium complexes [Pd(PPh₃)(C(O)- p-tolyl)L_OR] (R = Me, Prⁱ ). The palladium iodide complex [PdI(p-tolyl)(tmeda)] and the silver salt AgL_OR in the absence of PPh₃ form an unusual adduct [(p-tolyl)(tmeda)Pd(µ₂-I)AgL_OMe] that contains a short silver-iodide bond (Ag-I 2 · 703(1) Å). The silver-palladium bond is bridged by iodine (Pd-Ag 3 · 011(1), Pd{I 2 · 5934(9) Å) and the silver atom is coordinated by the tris-chelating oxygen ligand L_OMe.