To solve the problem of stability of organic luminescence radicals, Li et al. proposed a new kind of organic luminescence radicals with non-Aufbau electronic structure by using donor-acceptor molecular structure. The ...To solve the problem of stability of organic luminescence radicals, Li et al. proposed a new kind of organic luminescence radicals with non-Aufbau electronic structure by using donor-acceptor molecular structure. The stability of this kind of radicals was greatly improved and the high luminous efficiency was maintained. Using a non-Aufbau radical as the emission layer of an OLED, the maximum external efficiency of 5.3% has been achieved, which is among the highest efficiencies for pure organic near-intrared electroluminescence. This work has been published online in the Nature Materials on July 22,2019.展开更多
We report a donor-acceptor(D-A)type non-luminescent neutral radical,tris-2,4,6-trichlorophenylmethyl-N,N-dimethyl-9H-carbazol-3-amine(TTM-Cz-DMA).The results of cyclic voltammetry and quantum chemistry calculation con...We report a donor-acceptor(D-A)type non-luminescent neutral radical,tris-2,4,6-trichlorophenylmethyl-N,N-dimethyl-9H-carbazol-3-amine(TTM-Cz-DMA).The results of cyclic voltammetry and quantum chemistry calculation confirm TTM-Cz-DMA has the non-Aufbau electronic structure,which means the singly occupied molecular orbital(SOMO)lies below the highest doubly occupied molecular orbital(HOMO).The non-Aufbau electronic structure changes to the Aufbau electronic structure after protonation and exhibits proton-responsive turn-on fluorescence,which is totally reversible by deprotonation.The dihedral angle between donor and acceptor moieties of TTM-Cz-DMA in excited state reduces from 88°to 62°after protonation,causing the turn-on fluorescence.Our results offer a viewing angle to understand the luminescence of radicals and provide a possible application of proton detection.展开更多
The geometries and electronic structures of a series of electron donor-acceptor radical molecules have been studied theoretically.The computational results show that the introduction of substituents with strong electr...The geometries and electronic structures of a series of electron donor-acceptor radical molecules have been studied theoretically.The computational results show that the introduction of substituents with strong electron donating ability into tri-(2,4,6-trichlorophenyl)methyl(TTM)radicals enables the radical molecules to form the non-Aufbau electronic structure.The difficulty of forming the non-Aufbau electronic structure decreases with the enhancement of the electron donating ability of the substituent,but the expansion of the molecular conjugated system is not conducive to the formation.The hybridization of different fragments in molecular orbitals results in the disproportionation of orbital energy level and forms a staggered energy level structure.The electronic structure of radical molecules can be adjusted by substituents and molecular skeleton profoundly,which is a very effective means for molecular design.展开更多
文摘To solve the problem of stability of organic luminescence radicals, Li et al. proposed a new kind of organic luminescence radicals with non-Aufbau electronic structure by using donor-acceptor molecular structure. The stability of this kind of radicals was greatly improved and the high luminous efficiency was maintained. Using a non-Aufbau radical as the emission layer of an OLED, the maximum external efficiency of 5.3% has been achieved, which is among the highest efficiencies for pure organic near-intrared electroluminescence. This work has been published online in the Nature Materials on July 22,2019.
基金This work was supported by the National Natural Science Foundation of China(Nos.51925303 and 91833304)the Programme for Jilin University Science and Technology Innovative Research Team(JLUSTIRT),China(No.2019TD-33).
文摘We report a donor-acceptor(D-A)type non-luminescent neutral radical,tris-2,4,6-trichlorophenylmethyl-N,N-dimethyl-9H-carbazol-3-amine(TTM-Cz-DMA).The results of cyclic voltammetry and quantum chemistry calculation confirm TTM-Cz-DMA has the non-Aufbau electronic structure,which means the singly occupied molecular orbital(SOMO)lies below the highest doubly occupied molecular orbital(HOMO).The non-Aufbau electronic structure changes to the Aufbau electronic structure after protonation and exhibits proton-responsive turn-on fluorescence,which is totally reversible by deprotonation.The dihedral angle between donor and acceptor moieties of TTM-Cz-DMA in excited state reduces from 88°to 62°after protonation,causing the turn-on fluorescence.Our results offer a viewing angle to understand the luminescence of radicals and provide a possible application of proton detection.
基金‘14th Five-Year’Science and Technology Project of the Education Department of Jilin Province,China(No.JJKH20220966KJ)Open Fund of the State Key Laboratory of Luminescent Materials and Devices of South China University of Technology,China(No.2022-skllmd-09)LIXIN Outstanding Young Scholar Training Program of Jilin University,China.
文摘The geometries and electronic structures of a series of electron donor-acceptor radical molecules have been studied theoretically.The computational results show that the introduction of substituents with strong electron donating ability into tri-(2,4,6-trichlorophenyl)methyl(TTM)radicals enables the radical molecules to form the non-Aufbau electronic structure.The difficulty of forming the non-Aufbau electronic structure decreases with the enhancement of the electron donating ability of the substituent,but the expansion of the molecular conjugated system is not conducive to the formation.The hybridization of different fragments in molecular orbitals results in the disproportionation of orbital energy level and forms a staggered energy level structure.The electronic structure of radical molecules can be adjusted by substituents and molecular skeleton profoundly,which is a very effective means for molecular design.
