Methods of depositing a metal film with high purity are discussed. A catalyst enhanced CVD process is utilized comprising an alkyl halide catalyst soak and a precursor exposure. The precursor comprises a metal precursor having the general formula (I): M-L1(L2)y, wherein M is a metal, L1 is an aromatic ligand, L2 is an aliphatic ligand, and y is a number in the range of from 2 to 8 to form a metal film on the substrate surface, wherein the L2 comprises 1,5-hexdiene, 1,4-hexadiene, and less than 5% of 1,3-hexadiene. Selective deposition of a metal film with high purity on a metal surface over a dielectric surface is described.