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1.
Direct X‐ray Observation of Trapped CO2 in a Predesigned Porphyrinic Metal–Organic Framework
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Jacob A. Johnson Dr. Shuang Chen Tyler C. Reeson Dr. Yu‐Sheng Chen Prof. Xiao Cheng Zeng Prof. Jian Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(25):7632-7637
Metal–organic frameworks (MOFs) are emerging microporous materials that are promising for capture and sequestration of CO2 due to their tailorable binding properties. However, it remains a grand challenge to pre‐design a MOF with a precise, multivalent binding environment at the molecular level to enhance CO2 capture. Here, we report the design, synthesis, and direct X‐ray crystallographic observation of a porphyrinic MOF, UNLPF‐2, that contains CO2‐specific single molecular traps. Assembled from an octatopic porphyrin ligand with [Co2(COO)4] paddlewheel clusters, UNLPF‐2 provides an appropriate distance between the coordinatively unsaturated metal centers, which serve as the ideal binding sites for in situ generated CO2. The coordination of CoII in the porphyrin macrocycle is crucial and responsible for the formation of the required topology to trap CO2. By repeatedly releasing and recapturing CO2, UNLPL‐2 also exhibits recyclability. 相似文献
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Dr. Yiyin Mao Danke Chen Pan Hu Dr. Yi Guo Dr. Yulong Ying Dr. Wen Ying Prof. Dr. Xinsheng Peng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(43):15127-15132
Hierarchical porous materials are promising for catalyst, separation and sorption applications. A ligand‐assisted etching process is developed for template‐free synthesis of hierarchical mesoporous MOFs as single crystals and well‐intergrown membranes at 40 °C. At 223 K, the hierarchical porous structures significantly improve the CO2 capture capacity of HKUST‐1 by more than 44 % at pressures up to 20 kPa and 13 % at 100 kPa. Even at 323 K, the enhancement of CO2 uptake is above 25 % at pressures up to 20 kPa and 7 % at 100 kPa. The mesoporous structures not only enhance the CO2 uptake capacity but also improve the diffusion and mass transportation of CO2. Similarly, well‐intergrown mesoporous HKUST‐1 membranes are synthesized, which hold the potential for film‐like porous devices. Mesoporous MOF‐5 crystals are also obtained by a similar ligand‐assisted etching process. This may provide a facile way to prepare hierarchical porous MOF single crystals and membranes for wide‐ranging applications. 相似文献
3.
A Porphyrin‐Based Porous rtl Metal–Organic Framework as an Efficient Catalyst for the Cycloaddition of CO2 to Epoxides
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Dr. Wei Jiang Prof. Jin Yang Dr. Ying‐Ying Liu Dr. Shu‐Yan Song Prof. Jian‐Fang Ma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(47):16991-16997
A porous rtl metal–organic framework (MOF) [Mn5L(H2O)6?(DMA)2]?5DMA?4C2H5OH ( 1? Mn) (H10L=5,10,15,20‐tetra(4‐(3,5‐dicarboxylphenoxy)phenyl)porphyrin; DMA=N,N′‐dimethylacetamide) was synthesized by employing a new porphyrin‐based octacarboxylic acid ligand. 1? Mn exhibits high MnII density in the porous framework, providing it great Lewis‐acid heterogeneous catalytic capability for the cycloaddition of CO2 with epoxides. Strikingly, 1? Mn features excellent catalytic activity to the cycloaddition of CO2 to epoxides, with a remarkable initial turnover frequency 400 per mole of catalyst per hour at 20 atm. As‐synthesized 1? Mn also exhibits size selectivity to different epoxide substrates on account of their steric hindrance. The high catalytic activity, size selectivity, and stability toward the epoxides on catalytic cycloaddition of CO2 make 1? Mn a promising heterogeneous catalyst for fixation and utilization of CO2. 相似文献
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Lei Sun Dr. Michael G. Campbell Prof. Mircea Dincă 《Angewandte Chemie (International ed. in English)》2016,55(11):3566-3579
Owing to their outstanding structural, chemical, and functional diversity, metal–organic frameworks (MOFs) have attracted considerable attention over the last two decades in a variety of energy‐related applications. Notably missing among these, until recently, were applications that required good charge transport coexisting with porosity and high surface area. Although most MOFs are electrical insulators, several materials in this class have recently demonstrated excellent electrical conductivity and high charge mobility. Herein we review the synthetic and electronic design strategies that have been employed thus far for producing frameworks with permanent porosity and long‐range charge transport properties. In addition, key experiments that have been employed to demonstrate electrical transport, as well as selected applications for this subclass of MOFs, will be discussed. 相似文献
5.
Photoswitching CO2 Capture and Release in a Photochromic Diarylethene Metal–Organic Framework
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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
6.
Flexible and Hierarchical Metal–Organic Framework Composites for High‐Performance Catalysis
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Dr. Ning Huang Hannah Drake Jialuo Li Dr. Jiandong Pang Dr. Ying Wang Shuai Yuan Qi Wang Peiyu Cai Dr. Junsheng Qin Prof. Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2018,57(29):8916-8920
The development of porous composite materials is of great significance for their potentially improved performance over those of individual components and extensive applications in separation, energy storage, and heterogeneous catalysis. Now mesoporous metal–organic frameworks (MOFs) with macroporous melamine foam (MF) have been integrated using a one‐pot process, generating a series of MOF/MF composite materials with preserved crystallinity, hierarchical porosity, and increased stability over that of melamine foam. The MOF nanocrystals were threaded by the melamine foam networks, resembling a ball‐and‐stick model overall. The resulting MOF/MF composite materials were employed as an effective heterogeneous catalyst for the epoxidation of cholesteryl esters. Combining the advantages of interpenetrative mesoporous and macroporous structures, the MOF/melamine foam composite has higher dispersibility and more accessibility of catalytic sites, exhibiting excellent catalytic performance. 相似文献
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Beibei Zhou Tengwu Zeng Zhao‐Lin Shi Gen Zhang Satoshi Horike Yue‐Biao Zhang 《化学:亚洲杂志》2019,14(20):3552-3556
The function of allosteric enzymes can be activated or inhibited through binding of specific effector molecules. Herein, we describe how the skeletal deformation, pore configuration, and ultimately adsorptive behavior of a dynamic metal–organic framework (MOF), (Me2NH2)[In(atp)]2 (in which atp=2‐aminoterephthalate), are controlled by the allocation and orientation of its counter ions triggered by the inclusion/removal of different guest molecules. The power of such allosteric control in MOFs is highlighted through the optimization of the hydrocarbon separation performance by achieving multiple pore configurations but without altering the chemical composition. 相似文献
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Dr. Hui Liu Dr. Yonggang Zhao Zhijuan Zhang Nour Nijem Prof. Dr. Yves J. Chabal Prof. Dr. Xiangfang Peng Prof. Dr. Heping Zeng Prof. Dr. Jing Li 《化学:亚洲杂志》2013,8(4):778-785
We report two new 3D structures, [Zn3(bpdc)3(2,2′‐dmbpy)] (DMF)x(H2O)y ( 1 ) and [Zn3(bpdc)3(3,3′‐dmbpy)]?(DMF)4(H2O)0.5 ( 2 ), by methyl functionalization of the pillar ligand in [Zn3(bpdc)3(bpy)] (DMF)4?(H2O) ( 3 ) (bpdc=biphenyl‐4,4′‐dicarboxylic acid; z,z′‐dmbpy=z,z′‐dimethyl‐4,4′‐bipyridine; bpy=4,4′‐bipyridine). Single‐crystal X‐ray diffraction analysis indicates that 2 is isostructural to 3 , and the power X‐ray diffraction (PXRD) study shows a very similar framework of 1 to 2 and 3 . Both 1 and 2 are 3D porous structures made of Zn3(COO)6 secondary building units (SBUs) and 2,2′‐ or 3,3′‐dmbpy as pillar ligand. Thermogravimetric analysis (TGA) and PXRD studies reveal high thermal and water stability for both compounds. Gas‐adsorption studies show that the reduction of surface area and pore volume by introducing a methyl group to the bpy ligand leads to a decrease in H2 uptake for both compounds. However, CO2 adsorption experiments with 1′ (guest‐free 1 ) indicate significant enhancement in CO2 uptake, whereas for 2′ (guest‐free 2 ) the adsorbed amount is decreased. These results suggest that there are two opposing and competitive effects brought on by methyl functionalization: the enhancement due to increased isosteric heats of CO2 adsorption (Qst), and the detraction due to the reduction of surface area and pore volume. For 1′ , the enhancement effect dominates, which leads to a significantly higher uptake of CO2 than its parent compound 3′ (guest‐free 3 ). For 2′ , the detraction effect predominates, thereby resulting in reduced CO2 uptake relative to its parent structure 3′ . IR and Raman spectroscopic studies also present evidence for strong interaction between CO2 and methyl‐functionalized π moieties. Furthermore, all compounds exhibit high separation capability for CO2 over other small gases including CH4, CO, N2, and O2. 相似文献
10.
Chiral Metal–Organic Frameworks Bearing Free Carboxylic Acids for Organocatalyst Encapsulation
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Prof. Yan Liu Dr. Xiaobing Xi Chengcheng Ye Tengfei Gong Zhiwei Yang Prof. Yong Cui 《Angewandte Chemie (International ed. in English)》2014,53(50):13821-13825
Two chiral carboxylic acid functionalized micro‐ and mesoporous metal–organic frameworks (MOFs) are constructed by the stepwise assembly of triple‐stranded heptametallic helicates with six carboxylic acid groups. The mesoporous MOF with permanent porosity functions as a host for encapsulation of an enantiopure organic amine catalyst by combining carboxylic acids and chiral amines in situ through acid–base interactions. The organocatalyst‐loaded framework is shown to be an efficient and recyclable heterogeneous catalyst for the asymmetric direct aldol reactions with significantly enhanced stereoselectivity in relative to the homogeneous organocatalyst. 相似文献
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The electrochemical reduction of CO2 holds great promise for lowering the concentration of CO2 in the Earth′s atmosphere. However, several challenges have hindered the commercialization of this technology, including energy efficiency, the solubility of CO2 in the aqueous phase, and electrode stability. In this Minireview, we highlight and summarize the main advantages and limitations that metal–organic frameworks (MOFs) may offer in this field of research, either when used directly as electrocatalysts or when used as catalyst precursors. 相似文献
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A Highly Stable Zeotype Mesoporous Zirconium Metal–Organic Framework with Ultralarge Pores
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Dawei Feng Kecheng Wang Dr. Jie Su Dr. Tian‐Fu Liu Jihye Park Dr. Zhangwen Wei Mathieu Bosch Dr. Andrey Yakovenko Prof. Dr. Xiaodong Zou Prof. Dr. Hong‐Cai Zhou 《Angewandte Chemie (International ed. in English)》2015,54(1):149-154
Through topological rationalization, a zeotype mesoporous Zr‐containing metal–organic framework (MOF), namely PCN‐777, has been designed and synthesized. PCN‐777 exhibits the largest cage size of 3.8 nm and the highest pore volume of 2.8 cm3 g?1 among reported Zr‐MOFs. Moreover, PCN‐777 shows excellent stability in aqueous environments, which makes it an ideal candidate as a support to incorporate different functional moieties. Through facile internal surface modification, the interaction between PCN‐777 and different guests can be varied to realize efficient immobilization. 相似文献
16.
Yangyang Liu Dr. Jian‐Rong Li Wolfgang M. Verdegaal Tian‐Fu Liu Prof. Hong‐Cai Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(18):5637-5643
Four isostructural metal–organic frameworks (MOFs) with various functionalized pore surfaces were synthesized from a series of diisophthalate ligands. These MOFs exhibit a new network topology of {4.64.8}2{42.64}{64.82}2{66}. Hydrogen uptake as high as 2.67 wt % at 77 K/1 bar and CO2 uptake of 15.4 wt % at 297 K/1 bar have been observed for PCN‐308, which contains ? CF3 groups. The isostructural series of MOFs also showed reasonable adsorption selectivity of CO2 over CH4 and N2. 相似文献
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Metal–Organic Framework‐Templated Porous Carbon for Highly Efficient Catalysis: The Critical Role of Pyrrolic Nitrogen Species
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Gang Huang Li Yang Xiao Ma Prof. Dr. Jun Jiang Prof. Dr. Shu‐Hong Yu Prof. Dr. Hai‐Long Jiang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3470-3477
Metal‐free catalysts are of great importance and alternative candidates to conventional metal‐based catalysts for many reactions. Herein, several types of metal–organic frameworks have been exploited as templates/precursors to afford porous carbon materials with various nitrogen dopant forms and contents, degrees of graphitization, porosities, and surface areas. Amongst these materials, the PCN‐224‐templated porous carbon material optimized by pyrolysis at 700 °C (denoted as PCN‐224‐700) is composed of amorphous carbon coated with well‐defined graphene layers, offering a high surface area, hierarchical pores, and high nitrogen content (mainly, pyrrolic nitrogen species). Remarkably, as a metal‐free catalyst, PCN‐224‐700 exhibits a low activation energy and superior activity to most metallic catalysts in the catalytic reduction of 4‐nitrophenol to 4‐aminophenol. Theoretical investigations suggest that the content and type of the nitrogen dopant play crucial roles in determining the catalytic performance and that the pyrrolic nitrogen species makes the dominant contribution to this activity, which explains the excellent efficiency of the PCN‐224‐700 catalyst well. 相似文献
19.
Crystal Engineering of an nbo Topology Metal–Organic Framework for Chemical Fixation of CO2 under Ambient Conditions
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Wen‐Yang Gao Yao Chen Youhong Niu Kia Williams Lindsay Cash Pastor J. Perez Lukasz Wojtas Prof. Jianfeng Cai Yu‐Sheng Chen Prof. Shengqian Ma 《Angewandte Chemie (International ed. in English)》2014,53(10):2615-2619
Crystal engineering of the nbo metal–organic framework (MOF) platform MOF‐505 with a custom‐designed azamacrocycle ligand (1,4,7,10‐tetrazazcyclododecane‐N,N′,N′′,N′′′‐tetra‐p‐methylbenzoic acid) leads to a high density of well‐oriented Lewis active sites within the cuboctahedral cage in MMCF‐2, [Cu2(Cu‐tactmb)(H2O)3(NO3)2]. This MOF demonstrates high catalytic activity for the chemical fixation of CO2 into cyclic carbonates at room temperature under 1 atm pressure. 相似文献
20.
Encapsulation of an Interpenetrated Diamondoid Inorganic Building Block in a Metal–Organic Framework
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Dr. Huabin Zhang Dr. Ping Lin Dr. Erxia Chen Dr. Yanxi Tan Dr. Tian Wen Prof. Ali Aldalbahi Prof. Saad M. Alshehri Prof. Yusuke Yamauchi Prof. Shaowu Du Prof. Jian Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):4931-4934
The first example of an inorganic–organic composite framework with an interpenetrated diamondoid inorganic building block, featuring unique {InNa}n helices and {In12Na16} nano‐rings, has been constructed and structurally characterized. This framework also represents a unique example of encapsulation of an interpenetrated diamondoid inorganic building block in a metal–organic framework. 相似文献