The IAP was founded on June 2nd, 1961 as part of the faculty of natural sciences. Today about 56 employees research and teach in four divisions focusing on Biomedical Photonics, Laser Physics, Nonlinear Optics and Microwave Physics.
Optically Controlled Electron Transfer in a Re(I) Complex
We demonstrate ultrafast optical control of intramolecular charge flow which paves the way for photocurrent modulation and switching with a highly wavelength-selective ON/OFF ratio. The system we explore is a fac-[Re(CO)3(TTF-DPPZ)Cl] complex, where TTF-DPPZ = 4’,5’-bis(propylthio)tetrathiafulvenyl [i]dipyrido [3,2-a:2’,3’-c]phenazine. DFT calculations and AC-Stark spectroscopy confirm the presence of two distinct optically active charge-transfer processes, namely a metal-to-ligand charge transfer (MLCT) and an intra-ligand charge transfer (ILCT). Ultrafast transient absorption measurements show that the ILCT state decays in the ps regime. Upon excitation to the MLCT state, only a long-lived 3MLCT state is observed after 80 ps. Remarkably, however, the bleaching of the ILCT absorption band remains as a result of the effective inhibition of the HOMO-LUMO transition.