allyl) have been synthesized by reaction of (Siam)2ZrCl2 and Grignardreagents. The structures of (Siam)2ZrX2 (X = Cl, I, CH3 or CH2C6H5) and (Siam)3ZrCl have been investigated by X-raycrystalstructure analysis. (Siam)3ZrCl shows a capped octahedral structure with the coordination number 7 at the zirconium. (Siam)2ZrX2 compounds have distorted octahedral structures and the ligands occupy cis-positions