Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching

The suppression of thermally driven triplet deactivation is crucial for efficient persistent room-temperature phosphorescence (pRTP). However, the mechanism by which triplet deactivation occurs in metal-free molecular solids at room temperature (RT) remains unclear. Herein, we report a large pRTP in...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Tomoya Kusama, Shuzo Hirata
Formato:	article
Lenguaje:	EN
Publicado:	Frontiers Media S.A. 2021
Materias:	persistent room-temperature phosphorescence triplet quenching nonradiative deactivation phase change diffusion constant reorganization energy Chemistry QD1-999
Acceso en línea:	https://doaj.org/article/e05cd57765a64bb4adc73bcf1641cbb7
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:e05cd57765a64bb4adc73bcf1641cbb7
record_format	dspace
spelling	oai:doaj.org-article:e05cd57765a64bb4adc73bcf1641cbb72021-11-16T07:15:58ZThermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching2296-264610.3389/fchem.2021.788577https://doaj.org/article/e05cd57765a64bb4adc73bcf1641cbb72021-11-01T00:00:00Zhttps://www.frontiersin.org/articles/10.3389/fchem.2021.788577/fullhttps://doaj.org/toc/2296-2646The suppression of thermally driven triplet deactivation is crucial for efficient persistent room-temperature phosphorescence (pRTP). However, the mechanism by which triplet deactivation occurs in metal-free molecular solids at room temperature (RT) remains unclear. Herein, we report a large pRTP intensity change in a molecular guest that depended on the reversible amorphous–crystal phase change in the molecular host, and we confirm the large contribution made by the rigidity of the host in suppressing intermolecular triplet quenching in the guest. (S)-(−)-2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl ((S)-BINAP) was doped as a guest into a highly purified (S)-bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl ((S)-H8-BINAP) host. It was possible to reversibly form the amorphous and crystalline states of the solid by cooling to RT from various temperatures. The RTP yield (Φp) originating from the (S)-BINAP was 6.7% in the crystalline state of the (S)-H8-BINAP host, whereas it decreased to 0.31% in the amorphous state. Arrhenius plots showing the rate of nonradiative deactivation from the lowest triplet excited state (T1) of the amorphous and crystalline solids indicated that the large difference in Φp between the crystalline and amorphous states was mostly due to the discrepancy in the magnitude of quenching of intermolecular triplet energy transfer from the (S)-BINAP guest to the (S)-H8-BINAP host. Controlled analyses of the T1 energy of the guest and host, and of the reorganization energy of the intermolecular triplet energy transfer from the guest to the host, confirmed that the large difference in intermolecular triplet quenching was due to the discrepancy in the magnitude of the diffusion constant of the (S)-H8-BINAP host between its amorphous and crystalline states. Quantification of both the T1 energy and the diffusion constant of molecules used in solid materials is crucial for a meaningful discussion of the intermolecular triplet deactivation of various metal-free solid materials.Tomoya KusamaShuzo HirataFrontiers Media S.A.articlepersistent room-temperature phosphorescencetriplet quenchingnonradiative deactivationphase changediffusion constantreorganization energyChemistryQD1-999ENFrontiers in Chemistry, Vol 9 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	persistent room-temperature phosphorescence triplet quenching nonradiative deactivation phase change diffusion constant reorganization energy Chemistry QD1-999
spellingShingle	persistent room-temperature phosphorescence triplet quenching nonradiative deactivation phase change diffusion constant reorganization energy Chemistry QD1-999 Tomoya Kusama Shuzo Hirata Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching
description	The suppression of thermally driven triplet deactivation is crucial for efficient persistent room-temperature phosphorescence (pRTP). However, the mechanism by which triplet deactivation occurs in metal-free molecular solids at room temperature (RT) remains unclear. Herein, we report a large pRTP intensity change in a molecular guest that depended on the reversible amorphous–crystal phase change in the molecular host, and we confirm the large contribution made by the rigidity of the host in suppressing intermolecular triplet quenching in the guest. (S)-(−)-2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl ((S)-BINAP) was doped as a guest into a highly purified (S)-bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl ((S)-H8-BINAP) host. It was possible to reversibly form the amorphous and crystalline states of the solid by cooling to RT from various temperatures. The RTP yield (Φp) originating from the (S)-BINAP was 6.7% in the crystalline state of the (S)-H8-BINAP host, whereas it decreased to 0.31% in the amorphous state. Arrhenius plots showing the rate of nonradiative deactivation from the lowest triplet excited state (T1) of the amorphous and crystalline solids indicated that the large difference in Φp between the crystalline and amorphous states was mostly due to the discrepancy in the magnitude of quenching of intermolecular triplet energy transfer from the (S)-BINAP guest to the (S)-H8-BINAP host. Controlled analyses of the T1 energy of the guest and host, and of the reorganization energy of the intermolecular triplet energy transfer from the guest to the host, confirmed that the large difference in intermolecular triplet quenching was due to the discrepancy in the magnitude of the diffusion constant of the (S)-H8-BINAP host between its amorphous and crystalline states. Quantification of both the T1 energy and the diffusion constant of molecules used in solid materials is crucial for a meaningful discussion of the intermolecular triplet deactivation of various metal-free solid materials.
format	article
author	Tomoya Kusama Shuzo Hirata
author_facet	Tomoya Kusama Shuzo Hirata
author_sort	Tomoya Kusama
title	Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching
title_short	Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching
title_full	Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching
title_fullStr	Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching
title_full_unstemmed	Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching
title_sort	thermo-reversible persistent phosphorescence modulation reveals the large contribution made by rigidity to the suppression of endothermic intermolecular triplet quenching
publisher	Frontiers Media S.A.
publishDate	2021
url	https://doaj.org/article/e05cd57765a64bb4adc73bcf1641cbb7
work_keys_str_mv	AT tomoyakusama thermoreversiblepersistentphosphorescencemodulationrevealsthelargecontributionmadebyrigiditytothesuppressionofendothermicintermoleculartripletquenching AT shuzohirata thermoreversiblepersistentphosphorescencemodulationrevealsthelargecontributionmadebyrigiditytothesuppressionofendothermicintermoleculartripletquenching
_version_	1718426698421108736

Thermo-Reversible Persistent Phosphorescence Modulation Reveals the Large Contribution Made by Rigidity to the Suppression of Endothermic Intermolecular Triplet Quenching

Ejemplares similares