Reactions of the Dirhenium(II) Complexes Re2X4(μ-dppm)2 (X=Cl, Br; dppm=Ph2PCH2PPh2) with Isocyanides. XXII. A Comparison of Mixed Carbonyl–Isocyanide Complexes with Those Formed by Re2Cl4(μ-dcpm)2 (dcpm=Cy2PCH2PCy2)

Abstract

The reactions of the electron-rich triply bonded dirhenium(II) complex Re2Cl4(μ-dcpm)2 (dcpm=Cy2PCH2PCy2) with the isocyanide ligands XylNC (Xyl=2,6-dimethylphenyl) and t-BuNC afford the complexes Re2Cl4(μ-dcpm)2(CNXyl) and Re2Cl4(μ-dcpm)2(CN-t-Bu)2 which in turn react with CO to give salts of the [Re2Cl3(μ-dcpm)2(CO)2(CNXyl)]+ and [Re2Cl3(μ-dcpm)2(CN-t-Bu)2(CO)]+ cations which exist in different isomeric forms. This chemistry is compared with that developed previously for the analogous complexes derived from Re2Cl4(μ-dppm)2.