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991.
Photoswitching CO2 Capture and Release in a Photochromic Diarylethene Metal–Organic Framework 下载免费PDF全文
Prof. Dr. Feng Luo Prof. Dr. Cong Bin Fan Ming Biao Luo Dr. Xiao Liu Wu Yan Zhu Shou Zhi Pu Wen‐Yuan Xu Prof. Dr. Guo‐Cong Guo 《Angewandte Chemie (International ed. in English)》2014,53(35):9298-9301
We demonstrate herein a promising pathway towards low‐energy CO2 capture and release triggered by UV and visible light. A photosensitive diarylethene ligand was used to construct a photochromic diarylethene metal–organic framework (DMOF). A local photochromic reaction originating from the framework movement induced by the photoswitchable diarylethene unit resulted in record CO2‐desorption capacity of 75 % under static irradiation and 76 % under dynamic irradiation. 相似文献
992.
Influence of Central Metalloligand Geometry on Electronic Communication between Metals: Syntheses,Crystal Structures,MMCT Properties of Isomeric Cyanido‐Bridged Fe2Ru Complexes,and TDDFT Calculations 下载免费PDF全文
Dr. Xiao Ma Dr. Chen‐Sheng Lin Sheng‐Min Hu Dr. Chun‐Hong Tan Dr. Yue‐Hong Wen Prof. Dr. Tian‐Lu Sheng Prof. Xin‐Tao Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(23):7025-7036
To investigate how the central metalloligand geometry influences distant or vicinal metal‐to‐metal charge‐transfer (MMCT) properties of polynuclear complexes, cis‐ and trans‐isomeric heterotrimetallic complexes, and their one‐ and two‐electron oxidation products, cis/trans‐ [Cp(dppe)FeIINCRuII(phen)2CN‐FeII(dppe)Cp][PF6]2 (cis/trans‐ 1 [PF6]2), cis/trans‐[Cp(dppe)FeIINCRuII(phen)2CNFeIII‐(dppe)Cp][PF6]3 (cis/trans‐ 1 [PF6]3) and cis/trans‐[Cp(dppe)FeIIINCRuII(phen)2CN‐FeIII(dppe)Cp][PF6]4 (cis/trans‐ 1 [PF6]4) have been synthesized and characterized. Electrochemical measurements show the presence of electronic interactions between the two external FeII atoms of the cis‐ and trans‐isomeric complexes cis/trans‐ 1 [PF6]2. The electronic properties of all these complexes were studied and compared by spectroscopic techniques and TDDFT//DFT calculations. As expected, both mixed valence complexes cis/trans‐ 1 [PF6]3 exhibited different strong absorption signals in the NIR region, which should mainly be attributed to a transition from an MO that is delocalized over the RuII‐CN‐FeII subunit to a FeIII d orbital with some contributions from the co‐ligands. Moreover, the NIR transition energy in trans‐ 1 [PF6]3 is lower than that in cis‐ 1 [PF6]3, which is related to the symmetry of their molecular orbitals on the basis of the molecular orbital analysis. Also, the electronic spectra of the two‐electron oxidized complexes show that trans‐ 1 [PF6]4 possesses lower vicinal RuII→FeIII MMCT transition energy than cis‐ 1 [PF6]4. Moreover, the assignment of MMCT transition of the oxidized products and the differences of the electronic properties between the cis and trans complexes can be well rationalized using TDDFT//DFT calculations. 相似文献
993.
Targeted Functionalization of Porous Materials for Separation of Alcohol/Water Mixtures by Modular Assembly 下载免费PDF全文
Dr. Cai‐Xia Ren Prof. Min Ji Dr. Qing‐Xia Yao Li‐Xuan Cai Bin Tan Prof. Jie Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(45):14846-14852
Three isoreticular hydrogen‐bonded frameworks with functionalized pore structures were constructed by a modular self‐assembly process in which a series of amino acids with various substituents serve as facile exchange subassemblies to decorate the pore wall. The ordered amino acid side‐chain groups in the pore channels play an important role in determining the adsorption behavior of the framework materials, and ensure exclusive adsorption of methanol/water over ethanol. Gas‐chromatographic separation experiments demonstrated that alcohols can be efficiently separated from ternary water/methanol/ethanol mixtures and revealed a key influence of the adsorbate–host framework interaction on the practical separation performance of mixtures. 相似文献
994.
Yang Hu Lirong Tang Qilin Lu Siqun Wang Xuerong Chen Biao Huang 《Cellulose (London, England)》2014,21(3):1611-1618
Carboxylated cellulose nanocrystals (CCN) and cellulose nanocrystals (CNC) were prepared from borer powder of bamboo by two different kinds of procedures: one-step approach with ammonium persulfate for CCN and two-step approach with sulfuric acid for CNC. The obtained samples were characterizated by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and thermogravimetric analysis. The results show that the particles of CCN and CNC present spherical shape with diameters of 20–50 and 20–70 nm, respectively. The crystallinity of CCN and CNC is significantly improved after a series of chemical treatment, which is up to 62.75 and 69.84 %, respectively. The research indicates that the borer powder from bamboo could be an excellent raw material for manufacturing CNC in a low-cost and environmental-friendly way. Rational and sustainable utilization of the bamboo borer powder to develop new bioproducts holds great potential value for industry and offers many benefits and opportunities. 相似文献
995.
将PdCl2与ZIF-8的反应原料ZnO和2-甲基咪唑按照一定的比例,采用机械化学法原位将Pd2+负载在ZIF-8上(Pd2+/ZIF-8)。然后用NaBH4将Pd2+/ZIF-8进行还原,得到均匀分散的Pd纳米颗粒(Pd/ZIF-8)。通过XRD、N2吸附、透射电镜、ICP-AES、XPS等对Pd/ZIF-8的结构、形貌、价态等进行了表征。结果表明用机械化学法原位制备的Pd/ZIF-8具有分散均匀、容易大量制备的优点。该催化剂不仅能高效催化Suzuki-Miyaura交叉偶联反应,并且能够多次循环利用。 相似文献
996.
Highly Intensified Upconversion Luminescence of Ca2+‐doped Yb/Er:NaGdF4 Nanocrystals Prepared by a Solvothermal Route 下载免费PDF全文
Upon introducing Ca2+ dopants into the grain lattices by substituting Gd3+ ions, irregular Yb/Er:NaGdF4 nanocrystals prepared through a simple solvothermal route convert into highly uniform nanorods. Meanwhile, their upconversion luminescence intensifies by about 200 times, probably due to a modification of the crystal structure of NaGdF4 and an improvement in the crystallinity of the nanophase. 相似文献
997.
998.
《Solid State Ionics》2006,177(3-4):223-228
We study in detail the potential energy surface of Ga and Sr substituted Ba2In2O5 by considering the changes in the relative energies of the local structures of Ba2In2O5 when replacing 1 / 8th of the indium atoms with gallium or 1 / 8th of the barium atoms with strontium. The calculations are subsequently used to interpret the increase in ionic conductivity of cubic Ba2In2O5 when strontium is substituted for barium and the decrease in ionic conductivity when gallium is substituted for indium. The effects of replacing 1 / 8th of the indium atoms with gallium or 1 / 8th of the barium atoms with strontium are significant and affect considerably the relative stability of the different low energy local structures present for Ba2In2O5. While a higher density of low energy structures is observed for Ba1.75Sr0.25In2O5 than for Ba2In2O5, the opposite occurs for Ba2In1.75Ga0.25O5. This observation supports our main hypothesis: a high density of low energy local structures is a prerequisite for high ionic conductivity. 相似文献
999.
1000.
报道了用代数语言REDUCE模拟Hausdroff公式叠代展开过程的计算机程序SIMHAUS.并通过实例叙述了用SIMHAUS程序处理自旋体系在复杂哈密顿作用下的计算机辅助分析过程,为有关这方面的脉冲序列的分析和设计提供了一种新方法. 相似文献