Photochemistry and Photophysics of Charge-Transfer Excited States in Emissive / Heterobimetallic Titanocene Tweezer Complexes.

Transition-metal complexes that undergo ligand-to-metal charge transfer (LMCT) to metals are of interest as possible photocatalysts due to the lack of deactivating d-d states. Herein, the synthesis and characterization of nine titanocene complexes of the formula CpTi(CAr)·MX (where Ar = phenyl, dimethylaniline, or triphenylamine; and MX = CuCl, CuBr, or AgCl) are presented. Solid-state structural characterization demonstrates that MX coordinates to the alkyne tweezers and CuX coordination has a greater structural impact than AgCl.

A trans-bidentate bis-pyridinyl ligand with a transition metal hinge.

A titanocene based metalloligand, Cp*Ti(C2-py), was synthesized and coordinated to either Cu(i) or Pd(ii). The metalloligand binds Cu(i) between its alkynes and Pd(ii) between its pyridinyl rings, acting as a trans-bidentate ligand. In order to bind Pd(ii), significant structural rearrangements were necessary, which required the flexibility of the C-Ti-C hinge on the titanocene metalloligand.