Syntheses, Structures, and Reactivities of Novel Palladium β-Diiminato-Acetate Complexes

The reaction between (Ar(2)nacnac)H (Ar = C6H5, ligand a; 2,6-(Pr-i)(2)C6H3, ligand b) and [Pd(OAc)(2)] produces red complexes [Pd(Ar(2)nacnac)(OAc)] (1a: Ar = C6H5; 1b: Ar = 2,6-(Pr-i)(2)C6H3). Complex la has a dimeric structure in the solid state with two bridging acetates, while a monomer-dimer equilibrium establishes in solution. Complex I b is monomeric in both the solid state and solution. Both are air- and moisture-stable compounds, unlike [Pd(Ph(2)nacnac)(2)] (2), which easily hydrolyzes in the presence of moisture to give [Pd(Phnacac)(2)] (3) (Phnacac = {CH3C(NPh)CHC(O)CH3}(-)). Compound 1a reacts with metal acetates to produce heterotrimetallic complexes of a general formula [Pd(Ph(2)nacnac)](2)-mu-[M(OAc)(4)] (4, M = Cu; 5, M = Zn). Treating 1a with KOH in THF, or alternatively [Pd(Ph(2)nacnac)Cl](2) with (KOBu)-Bu-i in wet THF, produces [Pd(Ph(2)nacnac)(OH)](2) (6).