Preparation and characterization of dinuclear palladium tetraamin–thiophenolate complexes coligated by bridging acetate and acetamidate units

The aromatic thioether (2,6-bis((2-(dimethylamino)ethylamino)methyl)phenyl)(tert-butyl)sulfane (6) reacts with [Pd(NCCH3)2Cl2] under S–C bond cleavage to give the dinuclear palladium(II) complex [L3Pd2(μ-Cl)]2+ (7), where (L3)− = 2,6-bis((2-(dimethylamino)ethylamino)methyl)-thiophenolate. Complex 7 reacts readily with sodium acetate and sodium acetamide by the displacement of the bridging chloride group forming [L3Pd2(μ-OAc)]2+ (8) and [L3Pd2(μ-ONHCCH3)]2+ (9), respectively. Complex 8 can also be prepared by the reaction of 6 with [Pd(OAc)2]. All complexes were isolated as perchlorate salts and fully characterized by ESI-MS, IR, 1H, and 13C NMR spectroscopy. The structures of 7[ClO4] and 9[ClO4]2 have been determined by X-ray crystallography. The latter structure reveals a μ1,3-bridging acetamidate unit showing that (L3)− can alter its conformation sufficiently to accommodate a multi-atom bridging species between the two Pd atoms.

The synthesis and characterization of a new tetraamine-thiophenolate ligand (HL3) and three of its binuclear palladium complexes, namely [L3Pd2(Cl)]+, [L3Pd2(O2CCH3)]+, and [L3Pd2(ONHCMe)]+ are described. Their crystal structures clearly demonstrate the ability of the [L3Pd2]2+ fragment to accommodate single- and multiple atom bridging ligands.Figure optionsDownload as PowerPoint slide