Ultrafast Dynamical Study of Pyrene-N,N-dimethylaniline (PyDMA) as an Organic Molecular Diode in Solid State.

The journal of physical chemistry. B

PubMedID: 24601820

Thekku Veedu S, Raiser D, Kia R, Scholz M, Techert S. Ultrafast Dynamical Study of Pyrene-N,N-dimethylaniline (PyDMA) as an Organic Molecular Diode in Solid State. J Phys Chem B. 2014;.
Femtosecond optical pump-probe spectroscopy has been employed for studying the directly linked electron donor-acceptor system pyrene-N,N-dimethylaniline (PyDMA) in solid state. This DMA-pyrene derivative discussed is being applied as a molecular diode system switching on a ultrafast time scale. Our ultrafast solid state studies reveal a complex photochemistry of this molecular crystal system. Strong couplings of the optically induced charge transfer state with the radical ion pair state allow a femtosecond transition of the latter. One could see on the HOMO-LUMO description that a pure optical transition switches the system from a conducting to a blocked system since the molecular orbitals (MOs) of DMA moiety lies in a node plane of LUMO. Within 800 fs the system relaxes back to the ground state and/or forms radical ion pair, which is the surprising results of our study and on further probing the system, underwent vibrational cooling and enhanced population inversion of the radical ion pair.