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Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer

Thermometers whose emission color gradually changes with temperature are called chameleon emitters. In this study, we discuss the mechanism of the thermosensitivity of the emission color of polymers that contain two lanthanides (Ln(3+)), e.g., [Tb(0.99)Eu(0.01)(hfa)(3)(linker)]( n ), where the Ln(3+...

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Autores principales: Hatanaka, Miho, Hirai, Yuichi, Kitagawa, Yuichi, Nakanishi, Takayuki, Hasegawa, Yasuchika, Morokuma, Keiji
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Royal Society of Chemistry 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5365065/
https://www.ncbi.nlm.nih.gov/pubmed/28451188
http://dx.doi.org/10.1039/c6sc03006h
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author Hatanaka, Miho
Hirai, Yuichi
Kitagawa, Yuichi
Nakanishi, Takayuki
Hasegawa, Yasuchika
Morokuma, Keiji
author_facet Hatanaka, Miho
Hirai, Yuichi
Kitagawa, Yuichi
Nakanishi, Takayuki
Hasegawa, Yasuchika
Morokuma, Keiji
author_sort Hatanaka, Miho
collection PubMed
description Thermometers whose emission color gradually changes with temperature are called chameleon emitters. In this study, we discuss the mechanism of the thermosensitivity of the emission color of polymers that contain two lanthanides (Ln(3+)), e.g., [Tb(0.99)Eu(0.01)(hfa)(3)(linker)]( n ), where the Ln(3+)(hfa)(3) complexes (hfa: hexafluoro acetylacetonato) are connected by a phosphine oxide “linker” molecule. First, the difference in the thermosensitivities of the emissions from Tb(3+) and Eu(3+) are discussed. With increasing temperature, the green-emission intensity from Tb(3+) decreases whereas the red-emission intensity from Eu(3+) does not change. This was found to originate from the different reaction barriers for the quenching of the Ln(3+) excited state via the intersystem crossing (ISC) between the hfa-centered triplet state and the ground state. Next, the excitation energy transfer (EET) from Tb(3+) to Eu(3+) is discussed. Although the direct EET between Ln(3+) atoms is negligible because of the long distance between them, stepwise EET is found to occur via the linker-centered triplet state with a reasonable barrier. Thus, we propose a new idea—thermosensitivity can be controlled by the linker as well as by the ligand (hfa). To confirm the role of the linker, four phosphine oxides were examined. The thermosensitivity dependence on the linker is validated via experimental measurements.
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spelling pubmed-53650652017-04-27 Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer Hatanaka, Miho Hirai, Yuichi Kitagawa, Yuichi Nakanishi, Takayuki Hasegawa, Yasuchika Morokuma, Keiji Chem Sci Chemistry Thermometers whose emission color gradually changes with temperature are called chameleon emitters. In this study, we discuss the mechanism of the thermosensitivity of the emission color of polymers that contain two lanthanides (Ln(3+)), e.g., [Tb(0.99)Eu(0.01)(hfa)(3)(linker)]( n ), where the Ln(3+)(hfa)(3) complexes (hfa: hexafluoro acetylacetonato) are connected by a phosphine oxide “linker” molecule. First, the difference in the thermosensitivities of the emissions from Tb(3+) and Eu(3+) are discussed. With increasing temperature, the green-emission intensity from Tb(3+) decreases whereas the red-emission intensity from Eu(3+) does not change. This was found to originate from the different reaction barriers for the quenching of the Ln(3+) excited state via the intersystem crossing (ISC) between the hfa-centered triplet state and the ground state. Next, the excitation energy transfer (EET) from Tb(3+) to Eu(3+) is discussed. Although the direct EET between Ln(3+) atoms is negligible because of the long distance between them, stepwise EET is found to occur via the linker-centered triplet state with a reasonable barrier. Thus, we propose a new idea—thermosensitivity can be controlled by the linker as well as by the ligand (hfa). To confirm the role of the linker, four phosphine oxides were examined. The thermosensitivity dependence on the linker is validated via experimental measurements. Royal Society of Chemistry 2017-01-01 2016-08-25 /pmc/articles/PMC5365065/ /pubmed/28451188 http://dx.doi.org/10.1039/c6sc03006h Text en This journal is © The Royal Society of Chemistry 2016 https://creativecommons.org/licenses/by/3.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution 3.0 Unported License (http://creativecommons.org/licenses/by/3.0/ (https://creativecommons.org/licenses/by/3.0/) ) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Chemistry
Hatanaka, Miho
Hirai, Yuichi
Kitagawa, Yuichi
Nakanishi, Takayuki
Hasegawa, Yasuchika
Morokuma, Keiji
Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer
title Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer
title_full Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer
title_fullStr Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer
title_full_unstemmed Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer
title_short Organic linkers control the thermosensitivity of the emission intensities from Tb(iii) and Eu(iii) in a chameleon polymer
title_sort organic linkers control the thermosensitivity of the emission intensities from tb(iii) and eu(iii) in a chameleon polymer
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5365065/
https://www.ncbi.nlm.nih.gov/pubmed/28451188
http://dx.doi.org/10.1039/c6sc03006h
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