TY - JOUR
T1 - Achieving Thermally Activated Delayed Fluorescence from Benzophenone by Host-Guest Complexation
AU - Koninti, Raj Kumar
AU - Miyata, Kiyoshi
AU - Saigo, Masaki
AU - Onda, Ken
N1 - Funding Information:
This work was supported by the JSPS KAKENHI (Grant Numbers JP17H06375, 0JP19F19034, JP19K15508, JP20H05106, and JP20H05676), and the Iketani Science and Technology Foundation (ISTF). R.K.K. is thankful to JSPS postdoctoral fellowship for foreign researchers.
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/8/12
Y1 - 2021/8/12
N2 - Controlling luminescence behaviors of organic chromophores is essential for their applications. As emissions from chromophores are strongly modulated by structural fluctuations and external environments, their comprehensive understandings remain elusive. Here, we demonstrate the modulation of the photophysics of benzophenone (Bzp), a prototypical triplet sensor molecule, by encapsulating it into mesoporous silica nanomaterials (MSNs). We systematically probed photoluminescence property modulation using time-resolved photoluminescence (TR-PL) measurements. The strong confinement effect on Bzp in MSN heavily modifies the excited-state properties. A long-lived emission (40 μs) from the simplest organic chromophore was observed after host-guest complexation, and photoluminescence of Bzp is controlled with the host's framework structures. We analyzed temperature-dependent TR-PL behaviors and revealed that a host matrix induced thermally activated delayed fluorescence (TADF) from Bzp in the host-guest (Bzp:MSN) complex. The host-guest complexation efficiently suppresses intramolecular motions and significantly alters the singlet-triplet energy gap (ΔEST) to a sufficiently small value (<60 meV) and leads to efficient reverse intersystem crossing.
AB - Controlling luminescence behaviors of organic chromophores is essential for their applications. As emissions from chromophores are strongly modulated by structural fluctuations and external environments, their comprehensive understandings remain elusive. Here, we demonstrate the modulation of the photophysics of benzophenone (Bzp), a prototypical triplet sensor molecule, by encapsulating it into mesoporous silica nanomaterials (MSNs). We systematically probed photoluminescence property modulation using time-resolved photoluminescence (TR-PL) measurements. The strong confinement effect on Bzp in MSN heavily modifies the excited-state properties. A long-lived emission (40 μs) from the simplest organic chromophore was observed after host-guest complexation, and photoluminescence of Bzp is controlled with the host's framework structures. We analyzed temperature-dependent TR-PL behaviors and revealed that a host matrix induced thermally activated delayed fluorescence (TADF) from Bzp in the host-guest (Bzp:MSN) complex. The host-guest complexation efficiently suppresses intramolecular motions and significantly alters the singlet-triplet energy gap (ΔEST) to a sufficiently small value (<60 meV) and leads to efficient reverse intersystem crossing.
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U2 - 10.1021/acs.jpcc.1c04283
DO - 10.1021/acs.jpcc.1c04283
M3 - Article
AN - SCOPUS:85113348299
VL - 125
SP - 17392
EP - 17399
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 31
ER -