Controlling the energetics and lifetimes of excited states in unconventional chromophores: ligand-to-metal (LMCT) and metal-to-metal (MMCT) charge transfer
Seminar | February 17 | 4-5 p.m. | Pitzer Auditorium, 120 Latimer Hall
The discovery of new chromophores, particularly those synthesized from earth abundant elements, is critical for artificial photosynthesis to become a reality. The talk will address our work on unconventional chromophores based on LMCT and MMCT. We have identified an extremely long-lived LMCT excited state (1.6 ms at room temperature in methanol) and believe that this is a "symmetry trapped" excited state. The synthesis and photochemistry of new unsupported mu-oxido bridged heterobimetallic systems (Ti-O-M) composed entirely of earth-abundant elements will also be discussed. These molecules are being used to probe aspects of metal-to-metal charge transfer (MMCT) photochemistry. By varying the donor identity (M=Cr, Mn, Fe), magnetic coupling and spin state is controlled in both the ground and excited states. We have demonstrated that that intersystem crossing or spin-crossover (high spin -> low spin) can be tools for lengthening the lifetimes of such MMCT excited states.
Light refreshments will be served at 3:50pm in The Coffee Lab