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Cellulose conversion to polyols on supported Ru catalysts in aqueous basic solution

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Science China chemistry 2010年第7期53卷 1476-1480页

作者： DENG TianYin,SUN JiYing & LIU HaiChao beijing national laboratory for molecular sciences,State Key laboratory for Structural {2. of Stable and Unstable Species {3. {2. center,college of {2. and molecular engineering,peking university,{12. {13.,China 1. beijing national laboratory for molecular sciences State Key Laboratory for Structural Chemistry of Stable and Unstable Species Peking University Beijing 100871 China2. Green Chemistry Center College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

It is of great significance and challenge to achieve direct conversion of cellulose to specific polyols,e.g.,ethylene glycol and propylene *** such selective conversion,a novel one-pot approach was studied by combination of alkaline hydrolysis and hydrogenation on supported Ru catalysts.A wide range of bases including solid bases,e.g.,Ca(OH)2.and La2.3.and phosphate buffers were examined in the cellulose reaction in water,and the cellulose conversions and polyol products depended largely on the basicity or pH values in the aqueous *** glycol,1,2.propanediol,and especially 1,2.5-pentanetriol were obtained with selectivities of 15%,14% and 2.%,respectively,at 3.% cellulose conversion at pH 8 in phosphate buffer *** preliminary results provide potentials for efficient conversion of cellulose to targeted polyols by using the advantages of bases.

关键词： cellulose polyols Ru catalysts solid bases aqueous basic solutions

Luminescence resonance energy transfer based on β-NaYF_4:Yb,Er nanoparticles and TRITC dye

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Science China chemistry 2009年第10期52卷 1590-1595页

作者： SUN LingDong, GU JianQin, ZHANG ShuZhuo, ZHANG YaWen & YAN ChunHua beijing national laboratory for molecular sciences, State Key Lab of Rare Earth Materials chemistry and Applications & {2.-HKU Joint Lab in Rare Earth Materials and Bioinorganic chemistry, college of chemistry and molecular engineering, peking university, beijing 100871, China 1. beijing national laboratory for molecular sciences State Key Lab of Rare Earth Materials Chemistry and Applications & PKU-HKU Joint Lab in Rare Earth Materials and Bioinorganic Chemistry College of Chemistry and Molecular Engineering Peking University Beijing 100871 China

β-NaYF4:Yb,Er nanoparticles (NPs) are one of the most efficient upconversion materials, which can convert near-infrared light to higher-energy light through multiple photon absorptions or energy transfer. In addition, they may be attractive alternative donors for luminescence resonance energy transfer (LRET) studies, because of their sharp absorption and emission profiles, high quantum yields, large anti-stokes shifts, long lifetime, low toxicity, and superior photo-stability. In principle, many problems of fluorescence resonance energy transfer (FRET), such as excitation of acceptors, emission overlaps between donors and acceptors, high background noise, potential toxicity, and instability, can be overcome using β-NaYF4:Yb,Er NPs as energy donors. Because the organic coating induced separation can significantly reduce the energy transfer efficiency and aqueous FRET system is difficult to be applied in devices, we demonstrate a novel NP-dye LRET system in solid state. The emission of the β-NaYF4:Yb,Er NPs at 53. nm overlaps with the absorption of the tetrametrylrhodarnine isothiocyante (TRITC), satisfying the requirement of LRET process. Since TRITC molecules are adsorbed on the β-NaYF4:Yb,Er NPs by an electrostatic interaction, the interaction distance is suitable for LRET without any further modulation. The resultant solid LRET system is ready for the further applications for devices.

关键词： upconversion emission β-NaYF4:Yb Er nanoparticles TRITC assembly luminescence resonance energy transfer (LRET)

C-H Functionalization via Transition Metal Catalyzation

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C-H Functionalization via Transition Metal Catalyzation

中国化学会第二十五届学术年会

作者： Xiaobing Wan, Zhongxun Ma, Zhangjie Shi* beijing national laboratory for molecular sciences (BNLMS) and The Key laboratory of Bioorganic {2. and {3. engineering of Ministry of Education, college of {2. and green {2. center, peking university, beijing 100871, China and State Key laboratory of Organometallic {2., Chinese Academy of sciences, Shanghai 2.003., China

LiCl-Promoted Pd（Ⅱ）-Catalyzed ortho Carbonylation of N,N-Dimethylbenzylamines

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LiCl-Promoted Pd（Ⅱ）-Catalyzed ortho Carbonylation of N,N-...

第十六届全国金属有机化学学术讨论会

作者： Hu Li,~1 Gui-Xin Cai,~1 Zhang-Jie Shi~(*1,2. 1 beijing national {2. of {3. sciences(BNLMS),pku green chemistry center and Key {2. of Bioorganic chemistry and {3. {12. of Ministry of Education,{13. of chemistry, peking university,beijing 100871,China 2.State Key {2. of Organometallic chemistry,Chinese Academy of sciences,Shanghai 2.003.,China

＜正＞Palladium-catalyzed highly regioselective carbonylation of substituted N,N-dimethylbenzylamines was developed with the assistance of *** ortho-functionalized N,N-dimethylbenzylamine was further transformed into ...

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Fe-Catalyzed Cross-Coupling of Aryl and Vinyl Carboxylates with Grignard Reagents under Mild Conditions

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Fe-Catalyzed Cross-Coupling of Aryl and Vinyl Carboxylates w...

第十六届全国金属有机化学学术讨论会

作者： Bi-Jie Li,Li Xu,and Zhang-Jie Shi~* beijing national {2. of {3. sciences(BNLMS) and Key {2. of Bioorganic chemistry and {3. engineering of Ministry of Education,college of chemistry and green chemistry {13.,peking university,beijing 100080,China

＜正＞Previously,we have reported the nickel-catalyzed cross-coupling of aryl carboxylates with aryl boron and aryl zinc reagents,a class of novel transformation based on the C（aryl）-O bond *** reported herein an iron-catalyzed cross-coupling of aryl and vinyl carboxylates with Grignard reagents which proceeded with lower

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New Strategy to Construct Fused/Bridged/Spiro Carbocyclic Scaffolds Based on the Design of Novel 6-C Synthon Precursor

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New Strategy to Construct Fused/Bridged/Spiro Carbocyclic Sc...

第十六届全国金属有机化学学术讨论会

作者： Jia Liu,~(1,2) Xi Wang,~1 Chang-Liang Sun,~1 Bi-Jie Li,~1 Min Wang,~2 Zhang-Jie Shi~(*1,3. 1 beijing national {2. of {3. sciences(BNLMS) and Key {2. of Bioorganic chemistry and {3. engineering of Ministry of Education,college of chemistry and {3. engineering and {13. chemistry center,peking university,beijing 100871 and Department of chemistry,2 university of Agriculture of China,beijing 100094 and 3.State Key {2. of Organometallic chemistry,Shanghai Institute of Organic chemistry,Chinese Academy of sciences,Shanghai 20003.,China

＜正＞Fused/bridged/spiro carbocyclic ring scaffolds are one of most important motifs in natural and synthetic organic *** design a new 6-C synthon,which could be applied to construct complex poly-,spiro-and bridged systems through the simple sequential chemical transformations from acyclic precursor by a one-pot strategy from

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Microwave absorption of aluminum/hydrogen treated titanium dioxide nanoparticles

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Journal of Materiomics 2019年第1期5卷 133-146页

作者： Michael green Peng Xiang Zhanqiang Liu James Murowchick Xinyu Tan Fuqiang Huang Xiaobo Chen Department of chemistry University of MissourieKansas CityKansas CityMO64110USA college of Materials and Chemical engineering Hubei Provincial Collaborative Innovation Center for New Energy MicrogridChina Three Gorges UniversityYichang443002China State Key laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai200050China Department of Geosciences University of MissourieKansas CityKansas CityMO64110USA State Key laboratory of Rare Earth Materials chemistry and Applications College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

Interactions between incident electromagnetic energy and matter are of critical importance for numerous civil and military applications such as photocatalysis,solar cells,optics,radar detection,communications,information processing and transport et *** mechanisms for such interactions in the microwave frequency mainly rely on dipole rotations and magnetic domain *** this study,we present the first report of the microwave absorption of Al/H2.treated TiO_(2. nanoparticles,where the A_(l)/H_(2. treatment not only induces structural and optical property changes,but also largely improves the microwave absorption performance of TiO_(2. ***,the frequency of the microwave absorption can be finely controlled with the treatment temperature,and the absorption efficiency can reach optimal values with a careful temperature tuning.A large reflection loss of58.02.dB has been demonstrated with 3.1mm TiO_(2. coating when the treating temperature is 700℃.The high efficiency of microwave absorption is most likely linked to the disordering-induced property changes in the *** with the increased microwave absorption properties are largely increased visiblelight and IR absorptions,and enhanced electrical conductivity and reduced skin-depth,which is likely related to the interfacial defects within the TiO_(2. nanoparticles caused by the Al/H2.treatment.

关键词： Microwave absorption Black TiO_(2.nanoparticles Hydrogenation Aluminum reduction