Chemistry-An Asian Journal
·
2016
·Vol. 11
·期 18
·2555-2563
·
IF 4.592
Yafei Wang,Wanhui Liu,Jiyong Deng,Guohua Xie,Yuanwei Liao,Zuoming Qu,Hua Tan,Yu Liu,Weiguo Zhu
Pi-conjugated organic molecules featuring the donor–bridge–acceptor (D–π–A) structure have been widely used in semiconducting materials owing to their rigid structure, good thermal stability, excellent charge transfer, and high emission efficiency. To investigate the effect of the D–π–A molecular structure on the photophysical properties, in this contribution, three star-shaped D–π–A isomers based on the 2,4,6-triphenyl-1,3,5-triazine, spirofluorene, and triphenylamine moieties, that is, p -TFTPA, mp -TFTPA, and m -TFTPA, were synthesized by elaborately engineering the interconnecting position in the building-block units. The optophysical properties of these compounds were systematically explored by experiments and theory calculations. Definitively, changing the interconnecting position in these molecules played a significant role in the degree of π conjugation, which resulted in tunable emission colors from deep blue to green. Moreover, these isomers were employed as emissive dopants in organic light-emitting diodes. The highest external quantum efficiency of 2.3 % and current efficiency of 6.2 cd A −1 were achieved by using the p -TFTPA based device. This research demonstrates a feasible way to realize blue emitters by engineering D–π–A conjugation.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2024
·
IF 4.3
Hongji Jiang,Zhong Wang,Bing Mao,Yan Bing,Ning Sun,Jie Yuan
To investigate the effects of steric hindrance fluorene and heavy-atom bromine on the general optoelectronic properties of star-shaped organic emitters based on 9-(2-cyanophenyl) carbazole ( OCzPhCN ) frameworks, heavy element of bromine and steric hindrance fluorene were introduced into OCzPhCN to produce four derivatives of 2-(3-bromo-9H-carbazol-9-yl)benzonitrile ( BrCzPhCN) , 2-(3-bromo-6-(9-(4-ethoxyphenyl)-9H-fluoren-9-yl)-9H-carbazol-9-yl)benzonitrile (BrFCzPhCN) , 2-(3-(9-(4-ethoxyphenyl)-9H-fluoren-9-yl)-9H-carbazol-9-yl)benzonitrile (FCzPhCN) and 2-(3,6-bis(9-(4-ethoxyphenyl)-9H-fluoren-9-yl)-9H-carbazol-9-yl)benzonitrile (2FCzPhCN) . The fluorene units obviously improve the thermal stability of the obtained compounds, and 2FCzPhCN has the highest thermal stability with 5 % mass heat loss temperature reaching 447 °C. In different polar solvents, the absorption peaks wavelength of OCzPhCN , FCzPhCN and 2FCzPhCN are basically unchanged, and the redshifted emission peaks are positively correlated with solvent polarity. The photoluminescence quantum yields (PLQYs) of OCzPhCN , BrCzPhCN , FCzPhCN , BrFCzPhCN and 2FCzPhCN powders were 20.17 %, 5.43 %, 30.75 %, 3.27 % and 23.56 %. The fluorescence and phosphorescent quantum efficiencies of OCzPhCN , BrCzPhCN, FCzPhCN , BrFCzPhCN and 2FCzPhCN powders are 9.76 % and 10.41 %, 1.2 % and 3.23 %, 28.45 % and 2.3 %, 3.27 % and 0 %, 23.56 % and 0 %. OCzPhCN , BrCzPhCN and FCzPhCN powders show obvious room temperature phosphorescent emission, and the phosphorescent emission lifetime of OCzPhCN , BrCzPhCN and FCzPhCN powders at 561 nm, 576 nm and 568 nm are 193.17 ms, 18.65 ms and 7.25 ms. Compared with OCzPhCN, the introduction of bromine decreases the PLQY and the phosphorescent lifetime of BrCzPhCN powder, while the fluorescence quantum efficiency of the compound FCzPhCN powder has been improved. The corresponding single-triplet energy splitting (ΔE ST ) of OCzPhCN , FCzPhCN and 2FCzPhCN in solutions are 0.49 eV, 0.63 eV and 0.63 eV, and the corresponding ΔE ST values of OCzPhCN, BrCzPhCN FCzPhCN powders are 1.19 eV, 0.74 eV and 0.55 eV. The steric hindrance fluorene units result in smaller and stabilized ΔE ST in the solid powder states, and the same situation is opposite in the unimolecular solutions. The maximum external quantum efficiency of organic light-emitting diode based on 10,10′-(4,4′-sulfonylbis (4,1-phenylene)) bis (9,9-dimethyl-9,10-dihydroacridine) hosted by OCzPhCN reaches 12.7 %, and the external quantum efficiency at 100 cd/m 2 rolls down to 11 %. OCzPhCN is the best emitters in terms of room temperature phosphorescent emission and host applications.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
PubMed
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 25
·17771-17779
·
IF 3.9
Tao Lu,Wei Fang,Qian Zhou,Mengjuan Liu,Guozhang Wu
This study aims to synthesize a specific type of polycarbonate with high refractive index, low birefringence, and resistance to hygrothermal aging by copolymerizing 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthyl (BNE) with 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF). Comparative analysis revealed that the copolymer synthesized from BNE and BPEF demonstrated superior hydrolytic stability relative to the bisphenol A-based polycarbonate. This augmented stability can be attributed to the monomers' higher pKa values, rendering acidic substances less capable of dissociating and thereby mitigating ester hydrolysis under hygrothermal conditions. Furthermore, the investigation probed into the phenomenon of physical aging in copolymerized polycarbonate when exposed to hygrothermal environments. It was discerned that the enthalpy loss, observable under both dry and hygrothermal conditions, could be linearly correlated with the difference between the aging temperature and the glass transition temperature (Tg), signifying a close correlation between the magnitude of physical aging and Tg. A lower Tg in the copolymerized polycarbonate led to more pronounced physical aging within the same timeframe, resulting in an augmentation of tensile strength and modulus, while higher Tg effectively mitigated the physical aging phenomenon.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Feng Bao,Lishuai Zong,Nan Li,Yuanyuan Song,Yunxing Pan,Jinyan Wang,Xigao Jian
In this study, a series of poly(phthalazinone fluorenyl ether ketone ketone) (PPFEKK) copolymers were designed and synthesized via nucleophilic aromatic substitution polymerization of 1,4-bis(4-fluorobenzoyl)benzene (BFBB), 4-(4-hydroxyphenyl)(2 H)-phthalazin-1-one (DHPZ) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) to investigate the effects of bulky fluorene units on the processability and thermal degradation behavior of the polymers. The structures of the PPFEKKs were investigated and confirmed by FTIR, 1 H NMR, wide-angle X-ray diffraction (WAXD) and gel permeation chromatography (GPC) techniques. Traditional thermal measurements showed that the T d 5% and T d 10% values of the copolymers increased as the content of BHPF units increased from 0 to 100 mol%, while their glass transition temperatures gradually decreased. The rheological measurements showed that the processability of the copolymers significantly improved upon incorporation of BHPF units; the poly(aryl ether)s were less viscous and thus more processable. The thermal degradation kinetics were clarified using TGA with Kissinger’s method. The copolymer undergoes two thermal degradation processes: as the content of BHPF units in the copolymers increased from 0 to 100 mol%, the activation energy of the first degradation reaction increased from 228 to 254 kJ mol −1 , and the activation energy of the second degradation reaction increased from 271 to 298 kJ mol −1 . The resulting films displayed excellent tensile strength (higher than 76 MPa), and their Young’s modulus values were inversely proportional to their BHPF contents. Dynamic mechanical analysis showed storage modulus values at 30 °C of approximately 2662, 2826, 2698, 2791 and 2830 MPa for the prepared polymers. Furthermore, the PPFEKKs were soluble in a variety of organic solvents, making them suitable for film casting.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 7
·664-673
·
IF 2.804
Liu Ya-Di,Zhang Qiang,Yu Xin-Hong,Liu Jian-Gang,Han Yan-Chun
For poly(9,9-dioctylfuorene) (PFO), β phase (coplanar conformation with the intra-chain torsion angle of 165°) has a greater conjugation length and higher degree of order compared to those of α phase, which favors charge carrier transport. However, the highest content of β phase obtained so far is 45%. We propose to increase the content of β phase by promoting the solution aggregation of PFO molecules and extending film-forming time. For this purpose, 1,8-diiodooctane (DIO) is added to PFO o -xylene solution, which enhances the interaction of PFO chains and improves the planarity of PFO backbone, resulting in the formation of ordered aggregation. The aggregates act as nucleation centers to promote the formation of β phase. The content of β phase increases with increasing DIO concentration and reaches a platform of 39% as DIO is more than 4 vol%. Furthermore, the film is kept in a sealed environment with o -xylene atmosphere for 3 h, thus the PFO molecules have enough time to diffuse to the crystallization front and achieve disorder-order transition. As a result, the crystallinity of PFO is improved significantly and the content of β phase increases to 52%, reaching the highest value reported so far.
研究领域:
高分子化学
·
材料科学
·
凝聚态物理
·
纳米技术
·
光电材料
·
有机电子学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 217
·期 24
·2726-2735
·
IF 2.495
Huiliang Sun,Shuren Zhang,Yike Yang,Xiao Li,Hongmei Zhan,Yanxiang Cheng
Six aryl Pd(II) bromide complexes based on perylene diimide derivative (Ar) and phosphine mixed-ligands are successfully synthesized by directly oxidative addition of Ar–Br to the Pd(0) precursor. These complexes with the general formulas ArPdBr(PCy 3 ) 2 (PCy 3 = tricyclohexylphosphine; Pd1–Pd3 ) and [ArPdBr(TXP-2,4)] 2 (TXP-2,4 = tri-2,4-xylylphosphine; Pd4–Pd6 ) are stable and can be handled in air at room temperature. By employing the Pd(II) complexes as initiators, Suzuki catalyst transfer polymerization (SCTP) of AB-type fluorene monomer is investigated for preparing polyfluorenes (PFs) with the defined end group. Complexes Pd4–Pd6 with auxiliary TXP-2,4 ligand can initiate polymerization of AB-type fluorene monomer at room temperature, while higher polymerization temperature is required for Pd1–Pd3 with alkyl phosphine PCy 3 . The obtained polymers are analyzed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, which confirms that the Ar group is appended to the terminus of the polymer chain. Moreover, PFs prepared by Pd4–Pd6 -catalyzed SCTP bear precisely the Ar group on one chain end and 4- tert -butylphenyl end-capping group on the opposite end, which indicates that Pd4–Pd6 with the bulky TXP-2,4 exhibit better catalytic performance in SCTP. Photoluminescence spectra of the obtained polymers show a dual or a blue emission resulting from the difference of the molecular weight.
研究领域:
高分子化学
·
有机合成
·
功能材料
·
聚合反应机理
·
光电子材料
✓ 已验证
DOI
高影响因子
CURRENT ORGANIC SYNTHESIS
·
2015
·Vol. 12
·期 1
·71-75
·
IF 2.117
Nengquan Li,Kun Chen,Zhaokang Fan,Yiwu Quan,Qingmin Chen
A new family of bipolar hosts TPA-DAF, TPA-(DAF)2 and TPA-(DAF)3 based on triphenylamine and 4,5- diazafluorene moiety were synthesized through Friedel-Crafts reaction, and all of the three prepared hosts showed excellent thermal stability and exhibited blue fluorescence in solution.
研究领域:
有机电子学
·
光电材料
·
高分子化学
·
荧光材料
·
热稳定性研究
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 51
·45864-45872
·
IF 3.289
Yafei Wang,Jiang Fan,Tianyi Li,Qiong Wang,Junwei Shi,Zuoming Qu,Hua Tan,Yu Liu,Weiguo Zhu
Two binuclear platinum metallomesogens possessing a 6,12-dihydro-indeno[1,2-b]fluorene bridge, FJ-1 and FJ-2, have been synthesised and characterised by 1H and 13C NMR, TOF-MS and elemental analysis. Their thermal properties were studied by polarised optical microscopy and differential scanning calorimetry. Upon photoexcitation in solution, both complexes exhibited dual fluorescence (1π–π*)/phosphorescence (3π–π*) emission covering most of the visible spectrum (from about 460 nm to 750 nm). This uncommon behaviour has been further investigated by time-resolved optical spectroscopy, including nanosecond time-resolved transient absorption spectroscopy, and further insights were obtained by means of density functional theory (DFT) and time-dependent DFT (TD-DFT). An organic light-emitting diode (OLED) using FJ-1 was prepared. Importantly the two emission bands are retained in electroluminescence. This result suggests that controlling spin–orbit coupling to obtain dual emission can provide an effective way of achieving broadband emission based on a single molecule.
研究领域:
化学
·
材料科学
·
光物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 53
·期 12
·1457-1463
·
IF 3.113
Zilong Zhang,Pan Hu,Xiao Li,Hongmei Zhan,Yanxiang Cheng
Novel triarylamine-based coordination-saturated aryl Pd(II) halide complexes ligated by PEt 3 , PCy 3 , and P( o -tol) 3 were successfully synthesized by direct oxidative addition of aryl halide to the corresponding Pd(0) precursors. Suzuki–Miyaura coupling polymerization of 2-(7-halide-9,9-dioctylfluoren-2-yl)−1,3,2-dioxaborinane with these Pd(II) complexes as initiators was investigated for the synthesis of poly(fluorene)s with triarylamine end group. Pd(II) complexes with PCy 3 or P( o -tol) 3 exhibited catalytic activity and realized the catalyst-transfer polycondensation at 75 °C and room temperature, respectively, while the polymerization using Pd(II) catalyst ligated by PEt 3 did not proceed, which indicated that the bulky phosphine ligands could facilitate the reductive elimination and further promote the polymerization. In addition, the dimeric Pd(II) complex with P( o -tol) 3 can convert into monomeric Pd(II) intermediate with an open coordination site, which had a higher activity. The end groups of the afforded polyfluorene were analyzed by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, in which the Ar/H end groups are indicative of the catalyst-transfer polymerization. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53 , 1457–1463
研究领域:
高分子化学
·
有机合成
·
金属有机化学
·
功能材料
·
聚合反应机理
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 13
·20621-20636
·
IF 0
Yin Bingjie,Li Jingying,Guo Wei,Dong Haoqing,Zhang Guangshan,Xin Yanjun,Zhang Guodong,Chen Qinghua
Polycyclic aromatic hydrocarbons (PAHs) in soil are potentially harmful to human health. However, the use of photocatalysis technology to treat soil contaminated with PAHs remains challenging. Therefore, TiO 2 /α-FeOOH composite photocatalyst has been synthesized by hydrothermal method and sol–gel method and applied to photocatalytic degradation of fluoranthene in soil. The morphology, elements, crystal structure, optical properties, electrochemical characteristics, and photocatalytic activity of TiO 2 /α-FeOOH have been characterized. Results showed that TiO 2 is tightly fixed on the surface of α-FeOOH, and TiO 2 /α-FeOOH had higher photocatalytic activity on photocatalytic degradation of fluoranthene in soil under simulated sunlight. The degradation efficiency of TiO 2 /α-FeOOH is 3.0 and 4.8 times higher than that of TiO 2 and α-FeOOH, respectively. This is attributed to enhanced photocatalytic ability by enhancing the transfer capacity of electrons and holes and broadening the spectrum absorption range. The highest degradation efficiency was achieved when the pH of the soil is neutral, the ratio of water/soil is 10:1, and the dosage of catalyst is 50 mg/g. In addition, it was proved that •O 2 − , h + , and 1 O 2 are the main active substances in the photocatalysis of TiO 2 /α-FeOOH. The possible mechanism of a Z-type electron transfer structure was also proposed. The degradation products of fluoranthene were detected, and the degradation pathway was deduced.
研究领域:
环境科学
·
材料科学
·
催化
·
土壤修复
·
纳米技术
✓ 已验证
DOI
RSC Advances
·
2013
·Vol. 3
·期 35
·15467-15474
·
IF 2.562
Yufei Wang,Shuanjin Wang,Min Xiao,Dongmei Han,Michael A. Hickner,Yuezhong Meng
Sulfonated poly(fluorenyl ether ketone) (SPFEK) membranes have been first modified by layer-by-layer (LbL) self-assembly of positively charged polyelectrolyte PDDA (poly(diallyldimethylammonium chloride)) and negatively charged PSS (poly(sodium styrene sulfonate)). The membranes were investigated as an ion exchange membrane for vanadium redox flow batteries (VRBs). The permeability of the vanadium ions in VRBs was effectively suppressed by depositing the LbL thin film on the SPFEK membrane. The permeability decreased with increasing the number of PDDA/PSS bilayers. For the membrane with two self-assembly bilayers of PDDA/PSS, 50% and 10% of vanadium ion permeability of a pristine SPFEK and Nafion 117 membranes can be afforded, respectively. Moreover, the oxidative stability of the PDDA/PSS-SPFEK composite membrane is improved remarkably compared with the pristine one. Consequently, the performance of VRBs using the PDDA/PSS-SPFEK composite membrane exhibits the highest coulombic efficiency (CE) of 82.1% at 30 mA cm−2 and the longest duration stability in the self-discharge test.
研究领域:
电化学
·
能源材料
·
膜科学
·
储能技术
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Jingzhou Guo,Junwei Yang,Yuanzuo Zou,Yuan Pu,Dan Wang
The 9,9-Dihexyl-2,7-dibromofluorene (F6-Br) is an important intermediate product in the synthesis of functional polyfluorenes for various applications. The solvent/antisolvent method has been one of the efficient methods to purify organic molecules for advanced applications, for which the solubility data of solutes in different solvents are the basis of purification. In this work, the solubility values of F6-Br in 12 kinds of solvents in the temperature range of 283.15–323.15 K and atmospheric pressure were determined by using the isothermal saturation method. The selected solvents were methanol, ethanol, acetonitrile, n-butanol, isopropanol, dichloromethane, dimethyl sulfoxide, 1,4-dioxane, ethyl acetate, n-hexane, tetrahydrofuran, chloroform, and toluene. The measured solubility data were correlated by the modified Apelblat equation. The maximum value of mean square deviation was 3.95 × 10–3, which retains practical guiding significance. The purification of F6-Br via solvent/antisolvent precipitation processing was demonstrated, and the involvement of rotating packed-bed-based technology significantly intensified the process efficiency, which showed promising application value for industrial production.
研究领域:
化学工程
·
材料科学
·
有机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）