Synonyms: 1,3-Cyclopentadiene,1,2,3,4-tetramethyl-, zirconium complex; Bis(1,2,3,4-tetramethylcyclopentadienyl)zirconiumdichloride; Bis(tetramethylcyclopentadienyl)zirconium dichloride; Bis(h5-tetramethylcyclopentadienyl)zirconiumdichloride; Dichlorobis(tetramethylcyclopentadienyl)zirconium; Dichlorobis(h5-tetramethylcyclopentadienyl)zirconium