On account of the advantages of organic electroluminescent materials compared with their inorganic counterparts,the development of organic electroluminescent materials is one of the hot areas of the optoelectronic mat...On account of the advantages of organic electroluminescent materials compared with their inorganic counterparts,the development of organic electroluminescent materials is one of the hot areas of the optoelectronic materials.Fluorene and its derivatives,which have an aromatic biphenyl structure with a wide energy gap in the backbones and high luminescent efficiency,have drawn much attention of ma-terial chemists and device physicists.However,one drawback of fluorene-based electroluminescent blue materials is that there is an occurrence of long wavelength emission after annealing the films in air or after operating organic light-emitting diodes for a long time.To clarify the origin of this long wave-length emission,the scientists at home and abroad have put forward all kinds of correlative explana-tions.Among the scientists,some thought it was caused by excimer-related species,while some others claimed that it was caused by the fluorenone of photooxdized fluorene.The corresponding solutions to this problem have also been proposed and the problem has been partially resolved in some degree.The present review summarizes and analyzes the progress made on the origin of long wavelength emission in fluorene-based electroluminescent blue materials at home and abroad in the past few years.Some issues to be addressed and hotspots to be further investigated are also presented and discussed.展开更多
After the geometry optimization at B3LYP/6-31＋G（d,p） level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31＋G（d） level and B3LYP/6-311G＋（2d,p） level,re...After the geometry optimization at B3LYP/6-31＋G（d,p） level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31＋G（d） level and B3LYP/6-311G＋（2d,p） level,respectively.The 13C NMR chemical shifts calculated at HF/6-31＋G（d） level show better agreement with the observed values.By a series of linear correction equations （δpred=a ＋ bδcalc）,accurate prediction of 13C chemical shifts was achieved for the new fluorenone compound.The linear correlation of δpred with δexptl is excellent,and the square of correlation coefficient,r2,is up to 0.994.The maximum absolute difference between δpred and δexptl,Δδ,is 4.6 ppm,and the root-mean-square error between δpred and δexptl is only 2.6 ppm.展开更多
Highly efficient nonlinear optical（NLO） materials with well-defined architectures in the wavelength and subwavelength length scales are of particular importance for next generation of integrated photonic circuits. F...Highly efficient nonlinear optical（NLO） materials with well-defined architectures in the wavelength and subwavelength length scales are of particular importance for next generation of integrated photonic circuits. Fluorenone analogues have been demonstrated to be promising candidates as building blocks for assembly of organic NLO materials thanks to their synergistic supramolecular interactions and brilliant optical properties. Here we have studied the polymorphs of a phenylethynyl functionalized fluorenone derivative, and their controlled self-assembly for microstructures with different morphologies. These polymorphic microcrystals exhibit very distinctive NLO properties, highly related to their supramolecular and electronic structures.展开更多
A new fluorenone derivative, named chrysotoxone(3) was isolated from the ethanolic extract of the stems of Dendrobium chrysotoxum (Orchidaceae), along with three known compounds. The structure of the new fluorenone wa...A new fluorenone derivative, named chrysotoxone(3) was isolated from the ethanolic extract of the stems of Dendrobium chrysotoxum (Orchidaceae), along with three known compounds. The structure of the new fluorenone was elucidated as 2,5,8trihydroxy1,4dimethoxy9fluorenone.展开更多
Organic solid-state luminescent materials with high-efficiency deep-red emission have attracted considerable interest in recent years.Constructing donor-acceptor(D-A)type molecules has been one of most commonly used s...Organic solid-state luminescent materials with high-efficiency deep-red emission have attracted considerable interest in recent years.Constructing donor-acceptor(D-A)type molecules has been one of most commonly used strategies to achieve deep-red emission,but it is always difficult to achieve high photoluminescence(PL)quantum yield(ηPL)due to forbidden charge-transfer state.Herein,we report a new D-A type molecule 4-(7-(4-(diphenylamino)phenyl)-9-oxo-9H-fluoren-2-yl)benzonitrile(TPAFOCN),deriving from donor-acceptor-donor(D-A-D)type 2,7-bis(4-(diphenylamino)phenyl)-9H-fluoren-9-one(DTPA-FO)with a fluorescence maximum of 627 nm in solids.This molecular design enables a transformation of acceptor from fluorenone(FO)itself to 4-(9-oxo-9H-fluoren-2-yl)benzonitrile(FOCN).Compared with DTPA-FO,the introduction of cyanophenyl not only shifts the emission of TPA-FOCN to deep red with a fluorescence maximum of 668 nm in solids,but also maintains the highηPL of 10%.Additionally,a solution-processed non-doped organic light-emitting diode(OLED)was fabricated with TPA-FOCN as emitter.TPA-FOCN device showed a maximum luminous efficiency of 0.13 cd/A and a maximum external quantum efficiency(EQE)of 0.22%with CIE coordinates of(0.64,0.35).This work provides a valuable strategy for the rational design of high-efficiency deep-red emission materials using cyanophenyl as an ancillary acceptor.展开更多
基金the National Natural Science Foundation of China(Grant Nos:90406021,20774043and20574012)Natural Science Foundation of Jiangsu College Council(Grant No:KJD150148)Scientific Research Foundation of Nanjing University of Posts and Telecommunications(Grant No:NY206069)
文摘On account of the advantages of organic electroluminescent materials compared with their inorganic counterparts,the development of organic electroluminescent materials is one of the hot areas of the optoelectronic materials.Fluorene and its derivatives,which have an aromatic biphenyl structure with a wide energy gap in the backbones and high luminescent efficiency,have drawn much attention of ma-terial chemists and device physicists.However,one drawback of fluorene-based electroluminescent blue materials is that there is an occurrence of long wavelength emission after annealing the films in air or after operating organic light-emitting diodes for a long time.To clarify the origin of this long wave-length emission,the scientists at home and abroad have put forward all kinds of correlative explana-tions.Among the scientists,some thought it was caused by excimer-related species,while some others claimed that it was caused by the fluorenone of photooxdized fluorene.The corresponding solutions to this problem have also been proposed and the problem has been partially resolved in some degree.The present review summarizes and analyzes the progress made on the origin of long wavelength emission in fluorene-based electroluminescent blue materials at home and abroad in the past few years.Some issues to be addressed and hotspots to be further investigated are also presented and discussed.
文摘After the geometry optimization at B3LYP/6-31＋G（d,p） level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31＋G（d） level and B3LYP/6-311G＋（2d,p） level,respectively.The 13C NMR chemical shifts calculated at HF/6-31＋G（d） level show better agreement with the observed values.By a series of linear correction equations （δpred=a ＋ bδcalc）,accurate prediction of 13C chemical shifts was achieved for the new fluorenone compound.The linear correlation of δpred with δexptl is excellent,and the square of correlation coefficient,r2,is up to 0.994.The maximum absolute difference between δpred and δexptl,Δδ,is 4.6 ppm,and the root-mean-square error between δpred and δexptl is only 2.6 ppm.
基金the financial supports from the National Natural Science Foundation of China(NSFC) (Nos.21773168, 51503143 and 21761132007)the Tianjin Natural Science Foundation(No. 16JCQNJC05000)+5 种基金the Innovation Foundation of Tianjin University (No. 2016XRX-0017)the China International Science and Technology Projects(No. S2016G3413)The Netherlands Organization for Scientific Research (NWO) with the Veni Grant (No. 680-47-437)The Royal Netherlands Academy of Arts and Sciences(KNAW) with the China-Exchange Program (No. 530-4CDPO2)the Tianjin 1000 Youth Talents Planthe Chinese Scholarship Council (CSC)
文摘Highly efficient nonlinear optical（NLO） materials with well-defined architectures in the wavelength and subwavelength length scales are of particular importance for next generation of integrated photonic circuits. Fluorenone analogues have been demonstrated to be promising candidates as building blocks for assembly of organic NLO materials thanks to their synergistic supramolecular interactions and brilliant optical properties. Here we have studied the polymorphs of a phenylethynyl functionalized fluorenone derivative, and their controlled self-assembly for microstructures with different morphologies. These polymorphic microcrystals exhibit very distinctive NLO properties, highly related to their supramolecular and electronic structures.
文摘A new fluorenone derivative, named chrysotoxone(3) was isolated from the ethanolic extract of the stems of Dendrobium chrysotoxum (Orchidaceae), along with three known compounds. The structure of the new fluorenone was elucidated as 2,5,8trihydroxy1,4dimethoxy9fluorenone.
基金supported by the National Natural Science Foundation of China(Nos.91833304,51873077,51803071 and51673083)the National Basic Research Program of China(Nos.2015CB655003 and 2016YFB0401001)+2 种基金the Postdoctoral Innovation Talent Support Project(Nos.BX201700097 and BX20180121)the China Postdoctoral Science Foundation(Nos.2017M620108 and2018M641767)JLUSTIRT(No.2019TD-33)
文摘Organic solid-state luminescent materials with high-efficiency deep-red emission have attracted considerable interest in recent years.Constructing donor-acceptor(D-A)type molecules has been one of most commonly used strategies to achieve deep-red emission,but it is always difficult to achieve high photoluminescence(PL)quantum yield(ηPL)due to forbidden charge-transfer state.Herein,we report a new D-A type molecule 4-(7-(4-(diphenylamino)phenyl)-9-oxo-9H-fluoren-2-yl)benzonitrile(TPAFOCN),deriving from donor-acceptor-donor(D-A-D)type 2,7-bis(4-(diphenylamino)phenyl)-9H-fluoren-9-one(DTPA-FO)with a fluorescence maximum of 627 nm in solids.This molecular design enables a transformation of acceptor from fluorenone(FO)itself to 4-(9-oxo-9H-fluoren-2-yl)benzonitrile(FOCN).Compared with DTPA-FO,the introduction of cyanophenyl not only shifts the emission of TPA-FOCN to deep red with a fluorescence maximum of 668 nm in solids,but also maintains the highηPL of 10%.Additionally,a solution-processed non-doped organic light-emitting diode(OLED)was fabricated with TPA-FOCN as emitter.TPA-FOCN device showed a maximum luminous efficiency of 0.13 cd/A and a maximum external quantum efficiency(EQE)of 0.22%with CIE coordinates of(0.64,0.35).This work provides a valuable strategy for the rational design of high-efficiency deep-red emission materials using cyanophenyl as an ancillary acceptor.
