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991.
Dr. Tao Lei Chao Zhou Xiang-Zhu Wei Dr. Bing Yang Prof. Dr. Bin Chen Prof. Dr. Chen-Ho Tung Prof. Dr. Li-Zhu Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(3):879-884
[2+2] Photocycloaddition of two olefins is a general method to assemble the core scaffold, cyclobutane, found in numerous bioactive molecules. A new approach to synthesize cyclobutanes through multicomponent cascade reactions by merging aldol reaction and Witting reaction with visible-light-induced [2+2] cycloaddition is reported. An array of cyclobutanes with high selectivity has been achieved from commercially available aldehydes, ketones (or phosphorus ylide), and olefins with visible-light irradiation of a catalytic amount of (fac-tris(2-phenylpyridinato-C2,N)iridium) ([Ir(ppy)3]) at room temperature. Control experiments and spectroscopic studies revealed that the triplet–triplet energy transfer from the excited [Ir(ppy)3]* to enones, generated in situ from aldehyde and ketone or aldehyde and phosphorus ylide, is responsible for these simple and efficient muticomponent transformations. 相似文献
992.
Wang Zhongbing Liang Yanjie Peng Ning Peng Bing 《Journal of Thermal Analysis and Calorimetry》2019,136(5):2157-2164
Journal of Thermal Analysis and Calorimetry - This study aims to reduce zinc ferrite using carbon monoxide in the temperature range of 25–1000 °C using temperature-programmed... 相似文献
993.
Zhou Jiawen Zhu Weiya Zeng Miao Yang Qingqing Li Ping Lan Linfeng Peng Junbiao Li Yuan Huang Fei Cao Yong 《中国科学:化学(英文版)》2019,62(12):1656-1665
Stable radicals are challenging to prepare due to their intrinsic high reactivity. Herein, three trisphenolamine radicals were readily synthesized and exhibited unexpected thermal/electrochemical stability and semiconductor property. These three nitroxide radicals could be considered as a class of aromatized nitro groups or HNO_3 derivatives. The closed-shell nitro-like and open-shell nitroxide resonance structure contribute to their outstanding stability. Furthermore, the tunable ground states, extremely low band gap and p-type charge transport properties were systematically investigated. More importantly, the work presents the concept of aromatic inorganic acid radical(AIAR) and aggregation-induced radical(AIR) mechanism to understand the intrinsic structureproperty relationship of these radicals. In addition, we provide a novel strategy for the design of stable and low bandgap radicals for organic electronics, magnetics, spintronics, etc. 相似文献
994.
Miao Yan Hai-Ru Li Xiao-Yun Zhao Xiao-Qin Lu Yue-Wen Mu Hai-Gang Lu Si-Dian Li 《Journal of computational chemistry》2019,40(9):966-970
Based on detailed bonding analyses on the fluxional behaviors of planar B19−, tubular Ta@B20−, and cage-like B39−, we propose the concept of fluxional bonds in boron nanoclusters as an extension of the classical localized bonds and delocalized bonds in chemistry. © 2018 Wiley Periodicals, Inc. 相似文献
995.
Alex Durkin Ivan Taptygin Dr. Qingyuan Kong Mohamad F. M. Gunam Resul Abdul Rehman Dr. Ana M. L. Fernández Prof. Adam P. Harvey Prof. Nilay Shah Dr. Miao Guo 《ChemistryOpen》2019,8(6):668-688
Poly(limonene carbonate) (PLC) has been highlighted as an attractive substitute to petroleum derived plastics, due to its utilisation of CO2 and bio-based limonene as feedstocks, offering an effective carbon capture and utilisation pathway. Our study investigates the techno-economic viability and environmental sustainability of a novel process to produce PLC from citrus waste derived limonene, coupled with an anaerobic digestion process to enable energy cogeneration and waste recovery maximisation. Computational process design was integrated with a life cycle assessment to identify the sustainability improvement opportunities. PLC production was found to be economically viable, assuming sufficient citrus waste is supplied to the process, and environmentally preferable to polystyrene (PS) in various impact categories including climate change. However, it exhibited greater environmental burdens than PS across other impact categories, although the environmental performance could be improved with a waste recovery system, at the cost of a process design shift towards energy generation. Finally, our study quantified the potential contribution of PLC to mitigating the escape of atmospheric CO2 concentration from the planetary boundary. We emphasise the importance of a holistic approach to process design and highlight the potential impacts of biopolymers, which is instrumental in solving environmental problems facing the plastic industry and building a sustainable circular economy. 相似文献
996.
Xinshu Xia Shan Liu Kecai Xiong Wenyan Cai Tingyu Wei Yi Zhu Bing Liang Yating Wang Miao Wu Yanli Gai 《无机化学与普通化学杂志》2019,645(5):523-528
Four novel divalent lead coordination polymers based on a series of zwitterionic ligands, Pb2Cl4L1 ( 1 ), [Pb2Cl4L2]·2H2O ( 2 ), Pb2Cl2(CH3COO)2L2 ( 3 ), and Pb3Cl4(NO3)2L3 ( 4 ) were solvothermally synthesized and successfully characterized. Single crystal structure studies reveal that compound 1 is a chain structure based on the inorganic “PbCl2” chain motif, whereas compounds 2 – 4 are sheet structures each constructed by inorganic “PbCl2”, “PbCl(CH3COO)”, and “Pb3Cl4” chain motifs. Hydrogen bonding interactions in term of C–H ··· Cl and C–H ··· O play a key role to form supramolecular 3D structures of 1 – 4 . Additionally, studies of solid state fluorescence indicate 1 – 4 emit in the ultraviolet and visible region that can be assigned to the inter‐ligand π*–π and/or π*–n transitions. 相似文献
997.
Huang Hong-Liang Tang Bing Yi Qiao-Yan Wan Dan Yang Lin-Lin Liu Yun-Jun 《Transition Metal Chemistry》2019,44(1):11-24
Transition Metal Chemistry - Five new ruthenium(II) polypyridyl complexes [Ru(N–N)2(BTCP)](ClO4)2 (BTCP?=?2-(bicyclo[2.2.1]hept-5-en-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline;... 相似文献
998.
大面积高质量石墨烯的制备对石墨烯电子特性及石墨烯基纳器件相关研究有重要意义。本文综述了近几年来衬底上制备石墨烯的相关实验以及衬底与石墨烯相互作用研究的重要进展。目前,采用化学气相沉积、外延生长等方法可在衬底表面上制备出较大面积、高质量的石墨烯材料。衬底与石墨烯相互作用和界面间晶格匹配、原子成键及电荷转移等密切相关,其对吸附石墨烯的几何结构、能带结构及电子特性等产生明显影响。实验与理论计算的结合可望加深衬底与石墨烯作用机理的理解,指导衬底上石墨烯制备及改性的进一步研究。 相似文献
999.
采用线性循环溶出伏安法和差分脉冲溶出伏安法对磺胺嘧啶在电活化玻碳电极上的电化学行为进行了研究。玻碳电极在PBS溶液中(pH 7.0),用恒电位法在1.7 V阳极氧化400 s,在B-R缓冲溶液中,磺胺嘧啶在1.02V(vs.Ag/AgCl)处有一良好的氧化峰,在0.02~0.25 V/s范围内,其氧化峰电流与扫描速率呈良好线性关系,表明电极过程为受吸附控制的不可逆过程。差分脉冲溶出伏安法的氧化峰电流(Ipa)与磺胺嘧啶浓度1×10-6~1×10-4mol/L范围内呈良好的线性关系(r=0.9977),检出限为8.7×10-7mol/L(S/N=3)。方法已用于分析磺胺嘧啶片剂的分析。 相似文献
1000.
邻苯二甲酸L-(+)-2,3-O-亚异丙基苏力糖酯的两种构象式的螺旋结构与旋光性 总被引:2,自引:0,他引:2
在晶 (固 )态下 ,化合物邻苯二甲酸 L-( +) -2 ,3 -O-亚异丙基苏力糖酯存在两种不同的构象形式 ,利用螺旋片段判定规则及ω值 ,结合 X射线衍射数据及扭转角数据 ,对这两种构象形式的所有螺旋片段进行了分析 ,尽管两种构象形式的净值螺旋性相反 ,但仍然得出总净值螺旋性与旋光方向一致的结论 相似文献