Synthesis and characterization of a tert-butyl estersubstituted titanocene dichloride: t-BuOOCCp2TiCl2.

Bis[µ⁵-(tert-butoxycarbonyl)cyclopentadienyl]dichloridotitanium(IV), [Ti(C₁₀- H₁₃O₂)₂Cl₂], was synthesized from LiCp^COOt-Bu using TiCl₄, and was characterized by single-crystal X-ray diffraction and 1H NMR spectroscopy. The distorted tetrahedral geometry about the central titanium atom is relatively unchanged compared to Cp₂TiCl₂. The complex exhibits elongation of the titanium-- cyclopentadienyl 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 carboxylate anchoring groups for binding to metal oxide substrates. [ABSTRACT FROM AUTHOR]