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Triplet–Triplet Annihilation Upconversion in a MOF with Acceptor‐Filled Channels
Author(s) -
Gharaati Shadab,
Wang Cui,
Förster Christoph,
Weigert Florian,
ReschGenger Ute,
Heinze Katja
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201904945
Subject(s) - photon upconversion , annihilation , acceptor , photochemistry , intersystem crossing , materials science , mesoporous material , optoelectronics , doping , chemistry , organic chemistry , catalysis , physics , atomic physics , quantum mechanics , singlet state , excited state , condensed matter physics
Photon upconversion has enjoyed increased interest in the last years due to its high potential for solar‐energy harvesting and bioimaging. A challenge for triplet–triplet annihilation upconversion (TTA‐UC) processes is to realize these features in solid materials without undesired phase segregation and detrimental dye aggregation. To achieve this, we combine a palladium porphyrin sensitizer and a 9,10‐diphenylanthracene annihilator within a crystalline mesoporous metal–organic framework using an inverted design. In this modular TTA system, the framework walls constitute the fixed sensitizer, while caprylic acid coats the channels providing a solventlike environment for the mobile annihilator in the channels. The resulting solid material shows green‐to‐blue delayed upconverted emission with a luminescence lifetime of 373±5 μs, a threshold value of 329 mW cm −2 and a triplet–triplet energy transfer efficiency of 82 %. The versatile design allows straightforward changing of the acceptor amount and type.