Reaction of a palladium(II) complex chelated by a tridentate PNC ligand with water to produce a [(PN)Pd(mu-OH)](2)(2+) dimer: A rare observation of awell-defined hydrolysis of a Pd(II)-aryl compound

The potentially tridenate ligand o,o'-Ph2PC6H4C=NCH2C6H4Br (PNC-Br, 1), pre pared by a Schiff base condensation of 2-(diphenylphosphino)benzaldehyde an d 2-bromobenzylamine, reacts with Pd-2(dba)(3) (dba = dibenzylideneacetone) to form the (PNC)PdBr complex (2). Abstraction of the bromide ligand from 2 with AgBF4 in acetone-d(6) results in formation of the acetone adduct [(P NC)Pd(OC(CD3)(2))] [BF4] (3). Reaction of 3 with water lead to formation of the Pd(II) dimer [(PN)Pd(mu -OH)](2)[BF4](2) (4). That formation of dimer 4 occurs by protonation of the metal-bound aryl group of the PNC ligand by water was verified by a deuterium-labeling experiment. This is a rare examp le of protonation of a hydrocarbyl group from a d(8) square planar metal by water. 4 has been characterized by NMR, elemental analysis, and X-ray crys tallography, Reaction of 4 with 2-10 equiv of aniline or p-toluidine result s in the formation of the mixed dimer syn- [((PN)Pd)(2)(mu -NHAr)(mu -OH)][ BF4](2) (5).