Synthesis and characterization of a tert-butyl ester-substituted titanocene dichloride: Cp₂TiCl₂

Bis[η⁵-(tert-butoxyca-rbonyl)-cyclo-penta-dien-yl]di-chlorido-titanium(IV), [Ti(C₁₀H₁₃O₂)₂Cl₂], was synthesized from LiCp^COO using TiCl₄, and was characterized by single-crystal X-ray diffraction and ¹H NMR spectroscopy. The distorted tetra-hedral geometry about the central titanium atom is relatively unchanged compared to Cp₂TiCl₂. The complex exhibits elongation of the titanium-cyclo-penta-dienyl centroid distances [2.074 (3) and 2.070 (3) Å] and a contraction of the titanium-chlorine bond lengths [2.3222 (10) Å and 2.3423 (10) Å] relative to Cp₂TiCl₂. The dihedral angle formed by the planes of the Cp rings [52.56 (13)°] is smaller than seen in Cp₂TiCl₂. Both ester groups extend from the same side of the Cp rings, and occur on the same side of the complex as the chlorido ligands. The complex may serve as a convenient synthon for titanocene complexes with carboxyl-ate anchoring groups for binding to metal oxide substrates.