title: Vibrational coherence transfer in an electronically decoupled molecular dyad.
abstract: The ring opening of a dithienylethene photoswitch incorporated in a bridged boron-dipyrromethene - dithienylethene molecular dyad was investigated with ultrafast spectroscopy. Coherent vibrations in the electronic ground state of the boron-dipyrromethene are triggered after selective photoexcitation of the closed dithienylethene indicating vibrational coupling although the two moieties are electronically isolated. A distribution of short-lived modes and a long-lived mode at 143 cm(-1) are observed. Analysis of the theoretical frequency spectrum indicates two modes at 97 cm(-1) and 147 cm(-1) which strongly modulate the electronic transition energy. Both modes exhibit a characteristic displacement of the bridge suggesting that the mechanical momentum of the initial geometry change after photoexcitation of the dithienylethene is transduced to the boron-dipyrromethene. The relaxation to the dithienylethene electronic ground state is accompanied by significant heat dissipation into the surrounding medium. In the investigated dyad, the boron-dipyrromethene acts as probe for the ultrafast photophysical processes in the dithienylethene.
authors: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue Str. 7, D 60438 Frankfurt/M., Germany.
authors: Felix
authors: F
authors: Schweighöfer
authors: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue Str. 7, D 60438 Frankfurt/M., Germany.
authors: Lars
authors: L
authors: Dworak
authors: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue Str. 7, D 60438 Frankfurt/M., Germany.
authors: Markus
authors: M
authors: Braun
authors: TU-Berlin, Strasse des 17. Juni 135, D 10623 Berlin, Germany.
authors: Marc
authors: M
authors: Zastrow
authors: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue Str. 7, D 60438 Frankfurt/M., Germany.
authors: Jan
authors: J
authors: Wahl
authors: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue Str. 7, D 60438 Frankfurt/M., Germany.
authors: Irene
authors: I
authors: Burghardt
authors: TU-Berlin, Strasse des 17. Juni 135, D 10623 Berlin, Germany.
authors: Karola
authors: K
authors: Rück-Braun
authors: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue Str. 7, D 60438 Frankfurt/M., Germany.
authors: Josef
authors: J
authors: Wachtveitl