Convenient synthesis of the ruthenium complexes CpRu(diene)X (X=Cl, Br, I) by naphthalene substitution in [CpRu(C10H8)]+

The replacement of naphthalene ligand in the ruthenium complex [CpRu(C₁₀H₈)]⁺ by halide anions in the presence of 1,5-cyclooctadiene (cod) or norbornadiene (nbd) gives important synthetic precursors CpRu(cod)X and CpRu(nbd)X (X=Cl, Br, I) in 60–90% yield; the structure of CpRu(nbd)Br was determined by X-ray diffraction.