Reactions of [Pd(C6F5)2(CNR)2] with [PdCl2(NCPh)2]. Insertion of p-MeC6H4NC into Pd-C6F5 bonds

Pd(C₆F₅)₂(CNR)₂] (R = Cy, Bu^t, p-MeC₆H₄ (p-Tol)) react with PdCl₂(NCPh)₂] to give Pd₂(μ-Cl)₂(C₆F₅)₂(CNR)₂]. In refluxing benzene insertion of isocyanide into the C₆F₅Pd bonds occurs only for R = p-Tol, to give a imidoyl bridged polynuclear complex cis-Pd₂ (μ-Cl)₂μ-C(C₆F₅) = N(Tol-p)]_2n]. This complex reacts with (a) Tl(acac) to give Pd₂{μ-C(C₆F₅) = N(Tol-p)}₂(acac)₂]; (b) neutral monodentate ligands to afford dimeric complexes Pd₂{μ-C(C₆F₅) = N(Tol-p)}₂Cl₂L₂] (L = NMe₃, py, 4-Me-py, SC₄H₈), and (c) isocyanides to give insoluble complexes of the same composition which are thought to be polymeric, $\text{Pd}$(CNR)Cl{μ-C(C₆F₅) = $\text{N}$(p-Tol)}]_n (R = p-Tol, Me, Bu^t). Thermal decomposition of cis-Pd₂ (μ-Cl)₂ μ-C(C₆F₅) = N( p-Tol)]_2n] gives the diazabutadiene species (p-Tol)NC(C₆F₅)C(C₆F₅)N(p-Tol) in high yield.