Design Strategies for Luminescent Titanocenes: Improving the Photoluminescence and Photostability of Arylethynyltitanocenes.

Complexes that undergo ligand-to-metal charge transfer (LMCT) to d metals are of interest as possible photocatalysts. CpTi(CPh) (where CPh = phenylethynyl) was reported to be weakly emissive in room-temperature (RT) fluid solution from its phenylethynyl-to-Ti LMCT state but readily photodecomposes. Coordination of CuX between the alkyne ligands to give CpTi(CPh)CuX (X = Cl, Br) has been shown to significantly increase the photostability, but such complexes are not emissive in RT solution.