Cp2TiCl

Cp2TiCl is an organotitanium complex in which two cyclopentadienyl ligands (Cp) coordinate to titanium along with a terminal chloride. The complex represents a low-valent titanocene fragment, with titanium in the +3 oxidation state. Its structure is best viewed as a sandwich of two η5-Cp rings with a single chloride ligand, giving a reactive, electron-rich metal center.

Preparation and handling of Cp2TiCl typically involve the partial reduction of titanocene dichloride (Cp2TiCl2) or the in situ generation of the Ti(III) species under inert conditions. Common reducing agents include zinc, manganese, samarium diiodide, or electrochemical methods. Because of its low oxidation state and reactive nature, Cp2TiCl is usually highly air- and moisture-sensitive and is employed under strictly anhydrous, inert conditions.

Properties and reactivity of Cp2TiCl reflect its status as a single-electron transfer reagent. It is paramagnetic and can participate in radical-type transformations, transferring an electron to substrates such as organic halides or olefins and generating radical intermediates that can propagate a range of reactions. In practice, Cp2TiCl is most often generated and consumed in situ within a sequence that exploits its SET chemistry to initiate or mediate transformations in organic synthesis.

Applications of Cp2TiCl lie primarily in radical chemistry and organometallic studies as a versatile titanium(III) fragment. Related titanocene reagents, notably titanocene dichloride (Cp2TiCl2), are also central to this area and serve as benchmarks for understanding low-valent titanium chemistry and its applications.