On the efficacy of anthracene isomers for triplet transmission from CdSe nanocrystalsElectronic supplementary information (ESI) available. See DOI: 10.1039/c6cc08229g
The effect of isomeric substitutions on the transmitter for triplet energy transfer (TET) between nanocrystal (NC) donor and molecular acceptor is investigated. Each isomeric acceptor is expected to bind in a unique orientation with respect to the NC donor. We see that this orbital overlap drastical...
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Main Authors | , , , , , , |
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Format | Journal Article |
Language | English |
Published |
19.01.2017
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Online Access | Get full text |
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Summary: | The effect of isomeric substitutions on the transmitter for triplet energy transfer (TET) between nanocrystal (NC) donor and molecular acceptor is investigated. Each isomeric acceptor is expected to bind in a unique orientation with respect to the NC donor. We see that this orbital overlap drastically affects the transmission of triplets. Here, two functional groups, the carboxylic acid and dithiocarbamate, were varied between the 1-, 2- and 9-positions of the anthracene ring to give three
ACA
and three
ADTC
isomers. These six anthracene isomers served as transmitters for triplets between CdSe NC sensitizers and 9,10-diphenylanthracene annihilators for photon upconversion. The photon upconversion quantum yield (QY) is the highest for
9-ACA
(12%), lowest for
9-ADTC
(0.1%), around 3% for both
1-ACA
and
1-ADTC
, and about 1% for the 2-isomers. These trends in QYs are reflected in the rates of TET given by ultrafast transient absorption spectroscopy where a maximum of 3.8 × 10
7
s
−1
for
9-ACA
was measured. Molecular excited state energy levels were measured both in solution and polymer hosts to correlate structure to TET. This work confirms that anthracene excited states levels are very sensitive to molecular substitution, which in combination with orbital overlap, critically affect Dexter-based TET.
Isomeric substitutions on anthracene greatly effects triplet transmission from CdSe nanocrystals. |
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Bibliography: | 10.1039/c6cc08229g Electronic supplementary information (ESI) available. See DOI |
ISSN: | 1359-7345 1364-548X |
DOI: | 10.1039/c6cc08229g |