PALLADIUM(I) PHOSPHIDO-BRIDGED DINUCLEAR DERIVATIVES WITH PHOSPHITE LIGANDS

New mono-phosphido-bridged cationic derivatives of dipalladium(I) have been prepared by reacting [Pd-2(mu-PBu2t)(PPh3)(3)]BF4 (2)BF4, with P (OR)(3) (R=Me, Et, Ph). Under a large excess of the entering phosphite , all the PPh3 molecules terminally bonded to the central Pd-2(mu-PBu2 t) core can be substituted, yielding [Pd-2(mu-PBu2t) {P(OR)(3)}(4)]BF4 , [(4a)BF4, R = Me, (4b)BF4, R= Et and (4c)BF4, R=Ph]. The intermediat e mixed-ligand complex [Pd-2(mu-PBu2t)(PPh3) {P(OPh)(3)}(2)]BF4, (5)BF 4, was isolated in the reaction with P(OPh)(3). Moreover, the reaction s of the new complexes with CO, isoprene and CS2 were investigated and compared to the corresponding reactions of the phosphine-substituted complexes. (C) 1998 Elsevier Science Ltd. All rights reserved.