High quantum yield triplets, populated by initially prepared excited singlets, are desired for various energy conversion schemes in solid working compositions like porous MOFs. However, a large disparity in the distribution of the excitonic center of mass, singlet-triplet intersystem crossing (ISC) in such assemblies is inhibited, so much so that a carboxy-coordinated zirconium heavy metal ion cannot effectively facilitate the ISC through spin-orbit coupling. Circumventing this sluggish ISC, singlet fission (SF) is explored as a viable route to generating triplets in solution-stable MOFs. Efficient SF is achieved through a high degree of interchromophoric coupling that facilitates electron super-exchange to generate triplet pairs. Here we show that a predesigned chromophoric linker with extremely poor ISC efficiency (kISC) but ES1 ≥ 2ET1 form triplets in MOF in contrast to the frameworks that are built from linkers with sizable kISC but ES1 ≤ 2ET1. Finally, this work opens a new photophysical and photochemical avenue in MOF chemistry and utility in energy conversion schemes.
Surendran Rajasree, Sreehari, et al. "Triplet Generation Through Singlet Fission in Metal-Organic Framework: An Alternative Route to Inefficient Singlet-Triplet Intersystem Crossing." Angewandte Chemie (International Edition), vol. 62, no. 38, Jul. 2023. https://doi.org/10.1002/anie.202305323
Surendran Rajasree, Sreehari, Yu, Jierui, Fry, H. Christopher, et al., "Triplet Generation Through Singlet Fission in Metal-Organic Framework: An Alternative Route to Inefficient Singlet-Triplet Intersystem Crossing," Angewandte Chemie (International Edition) 62, no. 38 (2023), https://doi.org/10.1002/anie.202305323
@article{osti_2481332,
author = {Surendran Rajasree, Sreehari and Yu, Jierui and Fry, H. Christopher and Anderson, Ryther and Xu, Wenqian and Krishnan, Riya and Duan, Jiaxin and Goswami, Subhadip and A. Gómez‐Gualdrón, Diego and Deria, Pravas},
title = {Triplet Generation Through Singlet Fission in Metal-Organic Framework: An Alternative Route to Inefficient Singlet-Triplet Intersystem Crossing},
annote = {High quantum yield triplets, populated by initially prepared excited singlets, are desired for various energy conversion schemes in solid working compositions like porous MOFs. However, a large disparity in the distribution of the excitonic center of mass, singlet-triplet intersystem crossing (ISC) in such assemblies is inhibited, so much so that a carboxy-coordinated zirconium heavy metal ion cannot effectively facilitate the ISC through spin-orbit coupling. Circumventing this sluggish ISC, singlet fission (SF) is explored as a viable route to generating triplets in solution-stable MOFs. Efficient SF is achieved through a high degree of interchromophoric coupling that facilitates electron super-exchange to generate triplet pairs. Here we show that a predesigned chromophoric linker with extremely poor ISC efficiency (kISC) but ES1 ≥ 2ET1 form triplets in MOF in contrast to the frameworks that are built from linkers with sizable kISC but ES1 ≤ 2ET1. Finally, this work opens a new photophysical and photochemical avenue in MOF chemistry and utility in energy conversion schemes.},
doi = {10.1002/anie.202305323},
url = {https://www.osti.gov/biblio/2481332},
journal = {Angewandte Chemie (International Edition)},
issn = {ISSN 1433-7851},
number = {38},
volume = {62},
place = {United States},
publisher = {Wiley},
year = {2023},
month = {07}}