March 23, 2023
Tokyo Institute of Technology
Keio University
[Key Points]
Demonstrated that the intramolecular singlet fission of a pentacene dimer is affected by the solvent type and pressure.
Achieved the world's first transient absorption measurements under high pressure, elucidating the excited-state process.
A first step toward developing applications, such as in the medical field, for intramolecular singlet fission that responds to external stimuli.
A research team including Tomokazu Kinoshita, a first-year doctoral student, and Associate Professor Gaku Fukuhara of the Department of Chemistry, School of Science, Tokyo Institute of Technology, along with Professor Taku Hasobe and Visiting Researcher (at the time of research) Shunta Nakamura of the Department of Chemistry, Faculty of Science and Technology, Keio University, has demonstrated that the speed and efficiency of "singlet fission," a process that generates twice the number of excitons as photons absorbed by a molecule, change depending on the surrounding solvent and pressure. Intramolecular singlet fission in solution systems has attracted particular attention in recent years, with strategies generally focusing on changing the molecule's orientation or structure itself. This study focused on external stimuli, examining the effects of solvent and hydrostatic pressure on the singlet fission of a pentacene dimer in solution. The results revealed that in a pentacene dimer solution using a polar solvent, applying pressure promotes singlet fission. Furthermore, the excited state was examined in detail through transient absorption measurements. Achieving control through the external stimulus of pressure is expected not only to provide a guideline for designing new chromophores and improving efficiency but also to open up new avenues for a wide range of applications, such as the highly efficient generation of singlet oxygen, which is useful in cancer therapy.
This research was published in the February 23, 2023, issue (local time) of Chemical Science , a journal of the UK's Royal Society of Chemistry.
Please see below for the full press release.