General syntheses of unsymmetrical ansa-fluorenyl (flu)-containing ligands of the type flu-bridge-flu' (bridge: C2H4, CH2-SiMe2, SiMe2, SiPh2) and of the corresponding [flu-bridge-flu'] ZrCl2 metallocenes are described. Substituent effects in [2,7-R-2-flu-CH4-flu]ZrCl, (R: H, t-Bu. F, Cl) on rates of 1-octene polymerization are described. (C) 2004 Elsevier B.V. All rights reserved.