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环醚直接双羰基化合成α,ω-二元羧酸
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作者 马长坡 赖楹 +3 位作者 赵天歌 张小炫 刘海超 杨维冉 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第1期122-129,共8页
二元羧酸是制备聚酰胺、聚酯和聚氨酯的重要中间体,其传统合成途径具有一定的局限性.以己二酸为例,其主要工业生产工艺是利用硝酸氧化KA油,该方法存在KA油产量低和产生大量温室气体N2O等问题.因此,探索工艺绿色、原子有效和采用可再生... 二元羧酸是制备聚酰胺、聚酯和聚氨酯的重要中间体,其传统合成途径具有一定的局限性.以己二酸为例,其主要工业生产工艺是利用硝酸氧化KA油,该方法存在KA油产量低和产生大量温室气体N2O等问题.因此,探索工艺绿色、原子有效和采用可再生原料的二元羧酸制备方法具有重要意义.环醚和多元醇很容易从生物质原料中得到,以它们为原料,通过双羰基化直接制备二元羧酸,是一种非常有潜力的反应途径.但目前大多数文献报道由环醚或多元醇通过羰基化反应生成的产物主要是C+1单羧酸.本课题组一直致力于碘催化生物质衍生的多元醇的加氢脱氧,研究发现,在特定的反应条件下,多元醇可以选择性地形成多碘取代化合物的中间体.受此启发,本文报道了一种由环醚或多元醇形成二碘代物中间体,然后直接通过双羰基化反应生成对应的C+2二羧酸的新策略.由于己二酸是最重要的二元羧酸之一,且四氢呋喃(THF)可以从丰富的生物质衍生的糠醛中获得,本文重点研究了通过双羰基化反应直接利用THF合成己二酸.在优化的反应条件下,以铑盐为催化剂,碘为促进剂,乙酸和水为混合溶剂,在170℃,CO和H_(2)条件下,THF可以84%的产率转化为己二酸.循环实验结果表明,该催化体系在5次循环后仍能够稳定运行.该催化体系不仅适用于各种环醚,也适用于不同的伯二醇合成对应的C+2α,ω-二元羧酸.通过对反应中间体进行检测以及控制实验研究发现,选择性生成1,4-二碘丁烷中间体是进一步双羰基化制备己二酸的关键,而生成烯烃中间体和单碘代物中间体是形成副产物戊酸的主要原因.在实验结果和文献研究基础上,提出了THF转化为己二酸的反应机理.在反应中,活性铑常以Rh(I)的形式存在,并且从质谱中观察到了[Rh(CO)_(2)I_(2)]−阴离子,它可以在羰基化条件下由不同的铑前体(例如RhCl_(3))经过CO和碘还原后衍生.具体反应步骤为,首先铑催化剂催化H2和I2生成HI,然后THF与HI反应生成1,4-二碘丁烷中间体,此中间体经过铑催化活化在两端分别进行羰基化反应,最终生成产物己二酸.通过质谱检测到两个推测的中间体,进一步证实该反应机理.综上,本文为己二酸、戊二酸和其他重要的二羧酸(如1,7-庚二酸和1,8-辛二酸)的有效合成提供了一种新策略,为二元羧酸的高效、绿色合成提供参考. 展开更多
关键词 α ω-二元羧酸 双羰基化 环醚 多元醇 己二酸
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Critical approaches in the catalytic transformation of sugar isomerization and epimerization after Fischer-History,challenges,and prospects
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作者 Da-Ming Gao Xun Zhang +5 位作者 haichao liu Hidemi Fujino Tingzhou Lei Fuan Sun Jie Zhu Taoli Huhe 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第3期435-453,共19页
The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and... The transformation of aldose to ketose or common sugars into rare saccharides,including rare ketoses and aldoses,is of great value and interest to the food industry and for saccharidic biomass utilization,medicine,and the synthesis of drugs.Nowadays,high-fructose corn syrup(HFCS)is industrially produced in more than 10 million tons annually using immobilized glucose isomerase.Some low-calorie saccharides such as tagatose and psicose,which are becoming popular sweeteners,have also been produced on a pilot scale in order to replace sucrose and HFCS.However,current catalysts and catalytic processes are still difficult to utilize in biomass conversion and also have strong substrate dependence in producing high-value,rare sugars.Considering the specific reaction properties of saccharides and catalysts,since the pioneering discovery by Fischer,various catalysts and catalytic systems have been discovered or developed in attempts to extend the reaction pathways,improve the reaction efficiency,and to potentially produce commercial products.In this review,we trace the history of sugar isomerization/epimerization reactions and summarize the important breakthroughs for each reaction as well as the difficulties that remain unresolved to date. 展开更多
关键词 Rare sugars ISOMERIZATION Ketonization EPIMERIZATION Catalytic transformation
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Machine learning and bioinformatics to identify biomarkers in response to Burkholderia pseudomallei infection in mice
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作者 YAO FANG FEI XIA +5 位作者 FEIFEI TIAN L EI QU FANG YANG JUAN FANG ZHENHONG HU haichao liu 《BIOCELL》 SCIE 2024年第4期613-621,共9页
Objective:In the realm of Class I pathogens,Burkholderia pseudomallei(BP)stands out for its propensity to induce severe pathogenicity.Investigating the intricate interactions between BP and host cells is imperative fo... Objective:In the realm of Class I pathogens,Burkholderia pseudomallei(BP)stands out for its propensity to induce severe pathogenicity.Investigating the intricate interactions between BP and host cells is imperative for comprehending the dynamics of BP infection and discerning biomarkers indicative of the host cell response process.Methods:mRNA extraction from BP-infected mouse macrophages constituted the initial step of our study.Employing gene expression arrays,the extracted RNA underwent conversion into digital signals.The percentile shift method facilitated data processing,with the identification of genes manifesting significant differences accomplished through the application of the t-test.Subsequently,a comprehensive analysis involving Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway was conducted on the differentially expressed genes(DEGs).Leveraging the ESTIMATE algorithm,gene signatures were utilized to compute risk scores for gene expression data.Support vector machine analysis and gene enrichment scores were instrumental in establishing correlations between biomarkers and macrophages,followed by an evaluation of the predictive power of the identified biomarkers.Results:The functional and pathway associations of the DEGs predominantly centered around G protein-coupled receptors.A noteworthy positive correlation emerged between the blue module,consisting of 416 genes,and the StromaScore.FZD4,identified through support vector machine analysis among intersecting genes,indicated a robust interaction with macrophages,suggesting its potential as a robust biomarker.FZD4 exhibited commendable predictive efficacy,with BP infection inducing its expression in both macrophages and mouse lung tissue.Western blotting in macrophages confirmed a significant upregulation of FZD4 expression from 0.5 to 24 h post-infection.In mouse lung tissue,FZD4 manifested higher expression in the cytoplasm of pulmonary epithelial cells in BP-infected lungs than in the control group.Conclusion:Thesefindings underscore the upregulation of FZD4 expression by BP in both macrophages and lung tissue,pointing to its prospective role as a biomarker in the pathogenesis of BP infection. 展开更多
关键词 Burkholderia pseudomallei Microarray assay Machine learning BIOINFORMATICS FZD4
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Catalytic conversion of lignocellulosic biomass into chemicals and fuels 被引量:6
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作者 Weiping Deng Yunchao Feng +21 位作者 Jie Fu Haiwei Guo Yong Guo Buxing Han Zhicheng Jiang Lingzhao Kong Changzhi Li haichao liu Phuc T.T.Nguyen Puning Ren Feng Wang Shuai Wang Yanqin Wang Ye Wang Sie Shing Wong Kai Yan Ning Yan Xiaofei Yang Yuanbao Zhang Zhanrong Zhang Xianhai Zeng Hui Zhou 《Green Energy & Environment》 SCIE EI CSCD 2023年第1期10-114,共105页
In the search of alternative resources to make commodity chemicals and transportation fuels for a low carbon future,lignocellulosic biomass with over 180-billion-ton annual production rate has been identified as a pro... In the search of alternative resources to make commodity chemicals and transportation fuels for a low carbon future,lignocellulosic biomass with over 180-billion-ton annual production rate has been identified as a promising feedstock.This review focuses on the state-of-the-art catalytic transformation of lignocellulosic biomass into value-added chemicals and fuels.Following a brief introduction on the structure,major resources and pretreatment methods of lignocellulosic biomass,the catalytic conversion of three main components,i.e.,cellulose,hemicellulose and lignin,into various compounds are comprehensively discussed.Either in separate steps or in one-pot,cellulose and hemicellulose are hydrolyzed into sugars and upgraded into oxygen-containing chemicals such as 5-HMF,furfural,polyols,and organic acids,or even nitrogen-containing chemicals such as amino acids.On the other hand,lignin is first depolymerized into phenols,catechols,guaiacols,aldehydes and ketones,and then further transformed into hydrocarbon fuels,bioplastic precursors and bioactive compounds.The review then introduces the transformations of whole biomass via catalytic gasification,catalytic pyrolysis,as well as emerging strategies.Finally,opportunities,challenges and prospective of woody biomass valorization are highlighted. 展开更多
关键词 Lignocelullose BIOMASS Catalytic conversion Biofuels Renewable chemicals
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Base-free aerobic oxidation of glycerol on TiO_2-supported bimetallic Au–Pt catalysts 被引量:5
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作者 Yihong Shen Yuming Li haichao liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2015年第5期669-673,共5页
The aerobic oxidation of glycerol provides an economically viable route to glyceraldehyde, dihydroxyacetone and glyceric acid with versatile applications, for which monometallic Pt, Au and Pd and bimetallic Au–Pt, Au... The aerobic oxidation of glycerol provides an economically viable route to glyceraldehyde, dihydroxyacetone and glyceric acid with versatile applications, for which monometallic Pt, Au and Pd and bimetallic Au–Pt, Au–Pd and Pt–Pd catalysts on Ti O2 were examined under base-free conditions. Pt exhibited a superior activity relative to Pd, and Au–Pd and Pt–Pd while Au was essentially inactive. The presence of Au on the Au–Pt/Ti O2 catalysts led to their higher activities(normalized per Pt atom) in a wide range of Au/Pt atomic ratios(i.e.1/3–7/1), and the one with the Au/Pt ratio of 3/1 exhibited the highest activity. Such promoting effect is ascribed to the increased electron density on Pt via the electron transfer from Au to Pt, as characterized by the temperature-programmed desorption of CO and infra-red spectroscopy for CO adsorption. Meanwhile,the presence of Au on Au–Pt/Ti O2, most like due to the observed electron transfer, changed the product selectivity, and facilitated the oxidation of the secondary hydroxyl groups in glycerol, leading to the favorable formation of dihydroxyacetone over glyceraldehyde and glyceric acid that were derived from the oxidation of the primary hydroxyl groups. The synergetic effect between Au and Pt demonstrates the feasibility in the efficient oxidation of glycerol to the targeted products, for example, by rational tuning of the electronic properties of metal catalysts. 展开更多
关键词 铂催化剂 二氧化钛 双金属 游离氧 铂钯催化剂 二羟基丙酮 油基 负载
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Insights into support effects on Ce-Zr-O mixed oxide-supported gold catalysts in CO oxidation 被引量:4
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作者 Hongpeng Zhang haichao liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第1期98-106,共9页
Au/Ce1xZrxO2 catalysts (x=0-0.8) were prepared by a deposition-precipitation method using Ce1xZrxO2 nanoparticles as supports with variable Ce and Zr contents. Their structures were characterized by complimentary mean... Au/Ce1xZrxO2 catalysts (x=0-0.8) were prepared by a deposition-precipitation method using Ce1xZrxO2 nanoparticles as supports with variable Ce and Zr contents. Their structures were characterized by complimentary means such as X-ray diffraction, Raman, scanning transmission electron microscopy and X-ray photoelectron spectroscopy (XPS). These Au catalysts possessed similar sizes and crystalline phases of Ce1xZrxO2 supports as well as similar sizes and oxidation states of Au nanoparticles. The oxidation state of Au nanoparticles was dominated by Au 0 especially in CO oxidation. Their activities were examined in CO oxidation at different temperatures in the range of 303 333 K. The CO oxidation rates normalized per Au atoms increased with the increasing Ce contents, and reached the maximum value over Au/CeO2. Such change was in parallel with the change in the oxygen storage capacity values, i.e. the amounts of active oxygen species on Au/Ce1xZrxO2 catalysts. The excellent correlation between the two properties of the catalysts suggests that the intrinsic support effects on the CO oxidation rates is related to the effects on the adsorption and activation of O2 on Au/Ce1xZrxO2 catalysts. Such understanding on the support effects may be useful for designing more active Au catalysts, for example, by tuning the redox properties of oxide supports. 展开更多
关键词 金催化剂 CO氧化 混合氧化物 X射线光电子能谱 金纳米粒子 透射电子显微镜 氧化物载体 负载
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Promoting effect of chloride ions on selective oxidation of methanol to methyl formate over zirconia-supported ruthenium oxide catalysts 被引量:2
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作者 Weizhen Li Hongpeng Zhang +1 位作者 Xiaohui He haichao liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2013年第3期512-516,共5页
The effect of chloride ions on a monoclinic ZrO2-supported RuOx(RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate(MF) at a low tempe... The effect of chloride ions on a monoclinic ZrO2-supported RuOx(RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate(MF) at a low temperature of 373 K.The m-ZrO2 support was Cl-free,and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K.The structures of these catalysts were characterized by X-ray diffraction,Raman and X-ray photoelectron spectroscopies.Their reducibility was probed by temperature-programmed reduction in H2.The RuOx domains were present as highly dispersed RuO42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl- ions.Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity,whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2.The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates.This finding provides novel insights into the promoting effect of Cl ions on oxides-based catalysts for selective oxidation reactions. 展开更多
关键词 选择性氧化反应 钌催化剂 氯氧化锆 甲酸甲酯 离子对 氯化铵 甲醇 程序升温还原
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中国科学院大连化学物理研究所的历史及中日催化界友谊回顾(英文)
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作者 S. Ted Oyama Qin Xin +6 位作者 Guoxing Xiong Wenjie Shen Jie Xu Hongmei Yin Youzhu Yuan haichao liu Huidong Zheng 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第11期1591-1614,共24页
This article presents a history of the origins of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences (Abbreviated as DICP) and relates the recent friendship between China and Japan in the field of c... This article presents a history of the origins of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences (Abbreviated as DICP) and relates the recent friendship between China and Japan in the field of catalysis. Although the official beginning of DICP is in 1949 with the birth of the People's Republic of China, there are earlier roots that went back to the defeat of Russia by Imperial Japan in 1905. This began a period of occupation and exploitation of Northest Asia by Japan which did not end until its defeat by Allied forces in 1945. During the period of occupation, a laboratory was created called the Central Research Laboratory of the South Manchurian Railroad Company, which was staffed by the best and brightest researchers from Japan, and was able to develop new processes in chemicals and synthetic fuels that fed the Japanese Imperial forces. Between 1945 and 1949, Dalian was administered by the Soviet Union, and the removable equipment from the Laboratory was taken. In this period one individual stood out, the Laboratory Director Marusawa Tsuneya, who risked his life to preserve the scientific records and staff of the institute, and then stayed in Dalian for ten years after the Second World War to help China rebuild its capabilities. The Central Research Laboratory is still preserved as the Old Campus of DICP. The origin of the friendship between China and Japan in catalysis can be traced to Professor Morikawa Kiyoshi, who worked in the Central Research Laboratory and helped commercialize a shale coal liquefaction process. Upon his return to Japan he became Professor at the Tokyo Institute of Technology and in 1975 organized the first visit by Japanese academics to China. This was reciprocated in visits to Japan in 1977 and 1980 by top researchers such as Zhang Dayu, Min Enze, Tsai Khirui, Lu Jiaxi, and Lin Liwu. This resulted in numerous contacts between individuals, which multiplied geometrically. Notably among these were the personal interactions between Guo Xiexian, the Vice-Director of DICP and Tamaru Kenzi, a Professor at the University of Tokyo, which led to a friendship lasting decades and encompassing generations. In 1981, Guo Xiexian organized the first China-Japan-USA Symposium in Dalian, assisted by Tamaru Kenzi, which was attended by over 90 scientists. This meeting was a big success, and was to lead to the organization of many other multi-country conferences, further promoting exchanges. It culminated with the hosting of China of the 16th International Congress on Catalysis in 2016 in Beijing, with Li Can as President. Today DICP is a sprawling organization with over 1300 permanent staff, and is one of the powerhouses of catalysis in the world. From 2000, it has been led by Directors Bao Xinhe, Zhang Tao, and Liu Zhongmin. The Institute is making enormous contributions to research and producing cutting-edge technology, and its future is bright. 展开更多
关键词 went BACK a PERIOD of dicp
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Efficient aerobic oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid on Ru/C catalysts 被引量:8
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作者 Lufan Zheng Junqi Zhao +2 位作者 Zexue Du Baoning Zong haichao liu 《Science China Chemistry》 SCIE EI CAS CSCD 2017年第7期950-957,共8页
2,5-Furandicarboxylic(FDCA) is a potential substitute for petroleum-derived terephthalic acid, and aerobic oxidation of5-hydroxymethylfurfural(HMF) provides an efficient route to synthesis of FDCA. On an activated car... 2,5-Furandicarboxylic(FDCA) is a potential substitute for petroleum-derived terephthalic acid, and aerobic oxidation of5-hydroxymethylfurfural(HMF) provides an efficient route to synthesis of FDCA. On an activated carbon supported ruthenium(Ru/C) catalyst(with 5 wt% Ru loading), HMF was readily oxidized to FDCA in a high yield of 97.3% at 383 K and 1.0 MPa O_2 in the presence of Mg(OH)_2 as base additive. Ru/C was superior to Pt/C and Pd/C and also other supported Ru catalysts with similar sizes of metal nanoparticles(1–2 nm). The Ru/C catalysts were stable and recyclable, and their efficiency in the formation of FDCA increased with Ru loadings examined in the range of 0.5 wt%–5.0 wt%. Based on the kinetic studies including the effects of reaction time, reaction temperature, O_2 pressure, on the oxidation of HMF to FDCA on Ru/C, it was confirmed that the oxidation of HMF to FDCA proceeds involving the primary oxidation of HMF to 2,5-diformylfuran(DFF) intermediate, and its sequential oxidation to 5-formyl-2-furancarboxylic acid(FFCA) and ultimately to FDCA, in which the oxidation of FFCA to FDCA is the rate-determining step and dictates the overall formation rate of FDCA. This study provides directions towards efficient synthesis of FDCA from HMF, for example, by designing novel catalysts more efficient for the involved oxidation step of FFCA to FDCA. 展开更多
关键词 Ru/C催化剂 5-羟甲基糠醛 好氧氧化 对苯二甲酸 Ru/C催化剂 活性炭负载 呋喃 金属纳米颗粒
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Enhanced deep-red emission in donor-acceptor molecular architecture:The role of ancillary acceptor of cyanophenyl
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作者 Yue Shen Xiaohui Tang +4 位作者 Yuwei Xu haichao liu Shitong Zhang Bing Yang Yuguang Ma 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第11期1947-1950,共4页
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
关键词 Deep-red emission FLUORENONE Cyanophenyl group DONOR-ACCEPTOR Organic light-emitting diodes
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Recyclable Cu Salt-Derived Brønsted Acids for Hydrolytic Hydrogenation of Cellulose on Ru Catalyst
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作者 Yue liu Linxiao Chen +1 位作者 Wei Zhang haichao liu 《CCS Chemistry》 CAS 2022年第9期3162-3169,共8页
Brønsted acid-catalyzed hydrolysis of cellulose,the most abundant source of biomass in nature,is the critical step for its depolymerization and subsequent conversion to sugar alcohols and other important chemical... Brønsted acid-catalyzed hydrolysis of cellulose,the most abundant source of biomass in nature,is the critical step for its depolymerization and subsequent conversion to sugar alcohols and other important chemicals.Mineral acids are highly active;however,the difficulties in recycling and disposal limit their practical applications. 展开更多
关键词 CELLULOSE recyclable Brønsted acids hydrolysis sugar alcohols SORBITOL insoluble copper salt
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Modulating Room Temperature Phosphorescence by Oxidation of Thianthrene to Achieve Pure Organic Single-Molecule White-Light Emission
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作者 Yating Wen haichao liu +6 位作者 Shi-Tong Zhang Guocui Pan Zhiqiang Yang Tong Lu Bao Li Jungang Cao Bing Yang 《CCS Chemistry》 CAS 2021年第7期1940-1948,共9页
In order to develop pure organic single-molecule white-light emitters(SMWLE),the oxidation of thianthrene(TA)was performed on sulfur atoms at different degrees to tune room temperature phosphorescence(RTP)emission.Wit... In order to develop pure organic single-molecule white-light emitters(SMWLE),the oxidation of thianthrene(TA)was performed on sulfur atoms at different degrees to tune room temperature phosphorescence(RTP)emission.With increasing degrees of oxidation from 1OTA,2OTA,3OTA,to 4OTA,monomeric and aggregative RTP emission was gradually suppressed,due to the gradual disappearance of lone pair electrons on sulfur atoms.Among these compounds,monomers and aggregates of 1OTA demonstrated a better intensity match between fluorescence and RTP. 展开更多
关键词 single-molecule white light room temperature phosphorescence THIANTHRENE lone pair electrons spin–orbital coupling
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Thermally Activated Delayed Fluorescence of Aggregates Induced by Strongπ–πInteractions and Reversible Dual-Responsive Luminescence Switching
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作者 Xiangyu Zhang Tong Lu +6 位作者 Changjiang Zhou haichao liu Yating Wen Yue Shen Bao Li Shi-Tong Zhang Bing Yang 《CCS Chemistry》 CAS 2022年第2期625-637,共13页
A reversible dual-responsive luminescent material was introduced by our group to show the simultaneous color and lifetime switching in response to external stimuli.Pristine crystalline powder of(E)-2-(benzo[d]thiazol-... A reversible dual-responsive luminescent material was introduced by our group to show the simultaneous color and lifetime switching in response to external stimuli.Pristine crystalline powder of(E)-2-(benzo[d]thiazol-2-yl)-3-(pyren-1-yl)acrylonitrile(Py-BZTCN)shows the orderedπ–πstacking with only near-monomer-normal orange-yellow fluorescence,but it exhibits red emission with thermally activated delayed fluorescence(TADF)after grinding,which can be reversibly recovered by heating or fuming treatment.Grinding disturbs the orderedπ–πstacking of pristine powder,leading to the formation of small aggregates with compressed distance and increased overlap ofπ–πstacking between adjacent molecules.The cause of switching was verified by single-crystal X-ray diffraction experiments of two corresponding crystals.This strongπ–πinteraction effectively promotes the excited-state energy splitting and substantially decreases the singlet–triplet energy gap(ΔEST)of aggregates,resulting in the red TADF emission of aggregates through reverse intersystem crossing.This finding proposes a new route to realizing the TADF emission of aggregates through strong intermolecular interactions based on non-TADF monomer,thereby enabling a novel high-contrast dualresponsive luminescence switching. 展开更多
关键词 one-dimensionalπ-πstacking thermally activated delayed fluorescence stimuli-responsive luminescence switches D-A structure chargetransfer state
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