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)

The palladium complexes [Pd(PPh3)(aryl)L-OR] (aryl = Ph, p-tolyl; L-OR(-) = [(C5H5)Co{P(OR)(2)O}(3)](-), R = Me, Pr-i) have been prepared by reaction of [PdI(aryl)(tmeda)] (tmeda = N,N,N',N'-tetramethylethylenediamine) with the silver salts AgLOR 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, Pr-i). The palladium iodide complex [PdI(p-tolyl)(tmeda)] and the silver salt AgLOR in the absence of PPh3 form an unusual adduct [(p-tolyl)(tmeda)Pd(mu(2)-I)AgLOMe] that contains a short silver-iodide band (Ag-I 2.703(1) Angstrom). The silver-palladium bond is bridged by iodine (Pd-Ag 3.011(1), Pd-I 2.5934(9) Angstrom) and the silver atom is coordinated by the tris-chelating oxygen ligand L-OMe.