@article{b00b05503c9f4cf3a6e3da8623cebabb,
title = "Organic room-temperature phosphorescence from halogen-bonded organic frameworks: hidden electronic effects in rigidified chromophores",
abstract = "Development of purely organic materials displaying room-temperature phosphorescence (RTP) will expand the toolbox of inorganic phosphors for imaging, sensing or display applications. While molecular solids were found to suppress non-radiative energy dissipation and make the RTP process kinetically favourable, such an effect should be enhanced by the presence of multivalent directional non-covalent interactions. Here we report phosphorescence of a series of fast triplet-forming tetraethyl naphthalene-1,4,5,8-tetracarboxylates. Various numbers of bromo substituents were introduced to modulate intermolecular halogen-bonding interactions. Bright RTP with quantum yields up to 20% was observed when the molecule is surrounded by a Br⋯O halogen-bonded network. Spectroscopic and computational analyses revealed that judicious heavy-atom positioning suppresses non-radiative relaxation and enhances intersystem crossing at the same time. The latter effect was found to be facilitated by the orbital angular momentum change, in addition to the conventional heavy-atom effect. Our results suggest the potential of multivalent non-covalent interactions for excited-state conformation and electronic control. This journal is ",
author = "Jiawang Zhou and Ljiljana Stojanovi{\'c} and Berezin, {Andrey A.} and Tommaso Battisti and Abigail Gill and Kariuki, {Benson M.} and Davide Bonifazi and Rachel Crespo-Otero and Wasielewski, {Michael R.} and Wu, {Yi Lin}",
note = "Funding Information: D. B. gratefully acknowledges the EU through the MSCA-ITN-ETN (GA No. 722591 – project PHOTOTRAIN) and School of Chemistry at Cardiff University for generous nancial support. R. C.-O. acknowledges funding from the EPSRC (EP/R029385/1) and Leverhulme Trust (RPG-2019-122). This research utilised Queen Mary's Apocrita HPC facility. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Award DE-SC0020168 (M. R. W.). The authors thank Professor Kenneth D. M. Harris and Dr Colan E. Hughes (Cardiff) for the help with powder X-ray diffraction. Funding Information: D. B. gratefully acknowledges the EU through the MSCA-ITN-ETN (GA No. 722591 - project PHOTOTRAIN) and School of Chemistry at Cardiff University for generous financial support. R. C.-O. acknowledges funding from the EPSRC (EP/R029385/1) and Leverhulme Trust (RPG-2019-122). This research utilised Queen Mary's Apocrita HPC facility. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Award DE-SC0020168 (M. R. W.). The authors thank Professor Kenneth D. M. Harris and Dr Colan E. Hughes (Cardiff) for the help with powder X-ray diffraction. Publisher Copyright: {\textcopyright} 2021 The Royal Society of Chemistry.",
year = "2021",
month = jan,
day = "14",
doi = "10.1039/d0sc04646a",
language = "English (US)",
volume = "12",
pages = "767--773",
journal = "Chemical Science",
issn = "2041-6520",
publisher = "Royal Society of Chemistry",
number = "2",
}