A reaction between (η 5-C 5Me 5)TiCl 3 and C 5H 5Tl in benzene solution has afforded (η 5-C 5Me 5)(η 5-C 5H 5)TiCl 2 (I) in quantitative yield. (η 5-C 5Me 5)(η 5-C 5H 5)HfCl 2 (III) has been prepared in 83% yield from a reaction between (η 5-C 5Me 5)HfCl 3 and C 5H 5Na·DME in refluxing toluene solution. The crystal and molecular structures of (η 5-C 5Me 5)(η 5-C 5H 5TiCl 2 (I), (η 5-C 5Me 5)(η 5-C 5H 5)ZrCl 2 (II) and (η 5-C 5Me 5)(η 5-C 5H 5HfCl 2 (III) have been determined from X-ray data measured by counter methods. The three compounds are isostructural, crystallizing in the orthorhombic space group Pnma. The cell constants are: (I): a 9.873(1), b 12.989(3), c 11.376(4) Å and D calc 1.45 g cm −3 for Z = 4; (II): a 9.930(3), b 13.231(9), c 11.628(3) Å and D calc 1.58 g cm −3 for Z = 4; (III): a 9.938(1), b 13.156(2), c 11.582(2) Å and D calc 1.97 g cm −3 for Z = 4. In each case the metal atom resides on a crystallographic mirror plane which bisects both cyclopentadienyl rings and the ClMCl bond angle. The MCl bond lengths are 2.3518(9) for I, 2.4421(9) for II and 2.415(1) Å for III. The metal—cyclopentadienyl and metal—pentamethylcyclopentadienyl bond distances average 2.38(5) and 2.42(2) Å for I, 2.50(4) and 2.53(2) Å for II, and 2.48(4) and 2.50(1) Å for III respectively.