SYNTHESIS, X-RAY CRYSTAL-STRUCTURE AND REACTIVITY OF [(TMEDA)(P-TOLYL)PD(MU(2)-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)(2)O)(3)](-), R = ME, PR-I)

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'-tetramethylethylene diamine) with the silver salts AgLOR in the presence of PPh3. The comp lexes [Pd(PPh3)(aryl)L-OR] rapidly and reversibly insert carbon monoxi de 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)] an d 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-iodid e 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 ato m is coordinated by the tris-chelating oxygen ligand L-OMe.