TY - JOUR
T1 - Ultrafast trans → cis Photoisomerization Dynamics of Alkyl-Substituted Stilbenes in a Supramolecular Capsule
AU - Otolski, Christopher J.
AU - Mohan Raj, A.
AU - Sharma, Gaurav
AU - Prabhakar, Rajeev
AU - Ramamurthy, Vaidhyanathan
AU - Elles, Christopher G.
N1 - Funding Information:
This material is based upon work supported by the National Science Foundation under grants CHE-1151555 (CGE), CHE-1664926 (RP), and CHE-1807729 (VR).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/6/20
Y1 - 2019/6/20
N2 - Ultrafast spectroscopy reveals the effects of confinement on the excited-state photoisomerization dynamics for a series of alkyl-substituted trans-stilbenes encapsulated in the hydrophobic cavity of an aqueous supramolecular organic host-guest complex. Compared with the solvated compounds, encapsulated trans-stilbenes have broader excited-state absorption spectra, excited-state lifetimes that are 3-4 times longer, and photoisomerization quantum yields that are 1.7-6.5 times lower in the restricted environment. The organic capsule disrupts the equilibrium structure and restricts torsional rotation around the central C=C double bond in the excited state, which is an important motion for the relaxation of trans-stilbene from S1 to S0. The location and identity of alkyl substituents play a significant role in determining the excited-state dynamics and photoisomerization quantum yields by tuning the relative crowding inside the capsule. The results are discussed in terms of distortions of the ground- and excited-state potential energy surfaces, including the topology of the S1-S0 conical intersection.
AB - Ultrafast spectroscopy reveals the effects of confinement on the excited-state photoisomerization dynamics for a series of alkyl-substituted trans-stilbenes encapsulated in the hydrophobic cavity of an aqueous supramolecular organic host-guest complex. Compared with the solvated compounds, encapsulated trans-stilbenes have broader excited-state absorption spectra, excited-state lifetimes that are 3-4 times longer, and photoisomerization quantum yields that are 1.7-6.5 times lower in the restricted environment. The organic capsule disrupts the equilibrium structure and restricts torsional rotation around the central C=C double bond in the excited state, which is an important motion for the relaxation of trans-stilbene from S1 to S0. The location and identity of alkyl substituents play a significant role in determining the excited-state dynamics and photoisomerization quantum yields by tuning the relative crowding inside the capsule. The results are discussed in terms of distortions of the ground- and excited-state potential energy surfaces, including the topology of the S1-S0 conical intersection.
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U2 - 10.1021/acs.jpca.9b03285
DO - 10.1021/acs.jpca.9b03285
M3 - Article
C2 - 31140802
AN - SCOPUS:85067850075
VL - 123
SP - 5061
EP - 5071
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 24
ER -