Reactions of the dirhenium(II) complexes Re2X4(mu-dppm)(2) (X = Cl, Br; dppm = Ph2PCH2PPh2) with isocyanides. XXII. A comparison of mixed carbonyl-isocyanide complexes with those formed by Re2Cl4(mu-dcpm)(2) (dcpm = Cy2PCH2PCy2)

The reactions of the electron-rich triply bonded dirhenium(II) complex Re2C l4 (mu -dcpm)(2) (dcpm = Cy2PCH2PCy2) with the isocyanide ligands XylNC (Xy l = 2,6-dimethylphenyl) and t-BuNC afford the complexes Re2Cl4(mu -dcpm)(2) (CNXyl) and Re2Cl4(mu -dcpm)(2)(CN-t-Bu)(2) which in turn react with CO to give salts of the [Re2Cl3(mu -dcpm)(2)(CO)(2)(CNXyl)](+) and [Re2Cl3(mu -d cpm)(2)(CN-t-Bu)(2)(CO)](+) cations which exist in different isomeric forms . This chemistry is compared with that developed previously for the analogo us complexes derived from Re2Cl4(mu -dppm)(2).