TY - JOUR
T1 - Supramolecular-surface photochemistry
T2 - Supramolecular assembly organized on a clay surface facilitates energy transfer between an encapsulated donor and a free acceptor
AU - Ishida, Yohei
AU - Kulasekharan, Revathy
AU - Shimada, Tetsuya
AU - Ramamurthy, V.
AU - Takagi, Shinsuke
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/5/15
Y1 - 2014/5/15
N2 - We report the occurrence of efficient energy transfer reaction in a novel host-guest assembly composed of an anionic clay nanosheet, cationic porphyrin, and neutral aromatic molecule encapsulated within a cationic organic cavitand. The supramolecular assembly was prepared by the coadsorption of tetracationic Zn-porphyrin (acceptor) and 2-acetylanthracene (donor) enclosed within cationic organic cavitand (octaamine in its protonated form) on anionic clay nanosheets. In this arrangement under the interguest distance of 2.4 nm, almost 100% efficiency of singlet-singlet energy transfer was achieved. Detailed time-resolved fluorescence measurements revealed that the energy transfer rate constant could be attributed to a single component (1.9 × 109 s-1). This strongly suggests that the adsorption distribution of porphyrin and cavitand is rather uniform, not segregated. This is a progress from our previous study that involves energy transfer between two encapsulated neutral molecules. The use of Zn-porphyrin as an energy acceptor in this study enables to connect this energy transfer system to charge separation processes in the same manner as natural photosynthetic systems do; moreover, the efficiency of energy transfer reaction improved to almost 100% from 85% in the previous system between two cavitands.
AB - We report the occurrence of efficient energy transfer reaction in a novel host-guest assembly composed of an anionic clay nanosheet, cationic porphyrin, and neutral aromatic molecule encapsulated within a cationic organic cavitand. The supramolecular assembly was prepared by the coadsorption of tetracationic Zn-porphyrin (acceptor) and 2-acetylanthracene (donor) enclosed within cationic organic cavitand (octaamine in its protonated form) on anionic clay nanosheets. In this arrangement under the interguest distance of 2.4 nm, almost 100% efficiency of singlet-singlet energy transfer was achieved. Detailed time-resolved fluorescence measurements revealed that the energy transfer rate constant could be attributed to a single component (1.9 × 109 s-1). This strongly suggests that the adsorption distribution of porphyrin and cavitand is rather uniform, not segregated. This is a progress from our previous study that involves energy transfer between two encapsulated neutral molecules. The use of Zn-porphyrin as an energy acceptor in this study enables to connect this energy transfer system to charge separation processes in the same manner as natural photosynthetic systems do; moreover, the efficiency of energy transfer reaction improved to almost 100% from 85% in the previous system between two cavitands.
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U2 - 10.1021/jp502816j
DO - 10.1021/jp502816j
M3 - Article
AN - SCOPUS:84900818837
VL - 118
SP - 10198
EP - 10203
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 19
ER -