ISOLATION OF INTERMEDIATES IN HYDROGEN HALIDE ADDITIONS TO SOME IRIDIUM COMPLEXES

The complexes [Ir(cod)Ln]PF6(I, L = PPh3, PMePh2; n = 2. L = PMe2Ph; n = 3) react with HX to give [IrHX(cod)L2]PF6 (II, L = PMePh2 or PMe2Ph) or [IrHX2(cod)(PPh3)] (III). The intermediates [IrX(cod)L2] have, in two cases (L = PMePh2, X = I, Br), been directly isolated from the reaction mixtures at 0°C, and are also formed from I with KX (L = PPh3, X = Cl; L = PMePh2, X = Cl, Br, I); these intermediates protonate to give II (L = PMePh2), or an equimolar mixture of III and I (L = PPh3, X = Cl). Surprisingly, I2 reacts with I in MeOH to give III (L = PPh3). The stereochemistries of II and III were determined by < 1H NMR and especially by new methods using 13C NMR spectroscopy. The complexes I exhibit a Lewis acid reactivity pattern. © 1979.