Excellent fundamental research forms the basis for tomorrow’s solar energy technologies. Researchers from FAU Solar, led by spokesperson Prof. Dr. Dirk M. Guldi, together with collaborators from the Haley and Lu groups, have now published a new study in the Journal of the American Chemical Society (JACS). The work reveals how molecular vibrations govern light-induced spin conversion in organic open-shell materials, providing important insights for the rational design of next-generation optoelectronic and molecular energy-conversion systems.
Spin-Vibronic Coupling in Indenoindenodibenzothiophene Diradicaloids
The article “Spin-Vibronic Coupling in Indenoindenodibenzothiophene Diradicaloids”, recently published in the Journal of the American Chemical Society, reports how molecular motion can control light-induced spin conversion in organic open-shell systems. The study was carried out through a collaboration between the Guldi, Haley, and Lu groups, focusing on indenoindenodibenzothiophene (IIDBT) diradicaloids, a class of organic molecules with unusual electronic structures.
When these molecules absorb light, their electrons are promoted into excited states. This excitation, however, is not purely electronic: the molecular framework also responds through bond stretching, ring deformation, and collective vibrational motion. The study shows that selected vibrations can help couple electronic and spin degrees of freedom, thereby opening a pathway for the excited molecule to change its spin state. The mechanism is known as spin-vibronic coupling.
By comparing two closely related isomers, syn– and anti-IIDBT, the team demonstrated that small changes in molecular structure can strongly influence how efficiently light-triggered spin conversion occurs. These findings highlight the importance of molecular vibrations in open-shell organic materials and provide design principles for future optoelectronic and spintronic systems
The publication is available in the Journal of the American Chemical Society:
Spin-Vibronic Coupling in Indenoindenodibenzothiophene Diradicaloids
DOI: https://doi.org/10.1021/jacs.6c03953
Prof. Dr. Dirk Michael Guldi
Chair of Physical Chemistry I
Professors