Insertion reactions of 1,4-diisocyanobenzene in binuclear Pd(I) complexes

Reactions between XPd(μ-dmp)₂PdX′ (X = X′ = Cl, Br, I, NCO, SCN, N₃ or C₆F₅; X = C₆F₅, X′ = Cl, Br, I, NCO) with 1,4-diisocyanobenzene lead to the tetranuclear complexes (μ,μ′-CNC₆H₄NC){XPd(μ-dpm)₂PdX′}₂], where both ends of the diisocyanide are inserted in a metalmetal bond. The cationic derivatives (μ,μ′-CNC₆H₄NC){(RNC)Pd(μ-dpm)₂(CNR)}₂](BPh₄)₄ and (μ,μ′-CNC₆H₄NC){(RNC)Pd(μ-dpm)₂Pd(C₆F₅)}₂] (BPh₄)₂ (R = p-Tol, Cy, or ^tBu) are obtained by reacting (μ,μ′-CNC₆H₄NC){ClPd(μ-dpm)₂PdX}₂] (X= Cl or C₆F₅) with RNC in the presence of NaBPh₄. Treatment of (μ,μ′-CNC₆H₄NC){ClPd(μ-dpm)₂Pd(C₆F₅)}]₂ with NaBPh₄ causes the di-insertion and subsequent coordination of the isocyanide, yielding (C₆F₅)Pd(CN-C₆H₄NC) Pd(μ-dpm)₂Pd(C₆F₅)](BPh₄)₂.