MOLECULES
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2017
·Vol. 22
·期 11
·1952
·
IF 2.861
Qingqiang Tian,Suqin Shang,Huajun Wang,Guoqiang Shi,Zhiyao Li,Jianyong Yuan
A selective and practical bromine–metal exchange on bromoheterocyclics bearing substituents with an acidic proton under non-cryogenic conditions was developed by a simple modification of an existing protocol. Our protocol of using a combination ofi-PrMgCl andn-BuLi has not only solved the problem of intermolecular quenching that often occurred when using alkyl lithium alone as the reagent for halogen–lithium exchange, but also offered a highly selective method for performing bromo–metal exchange on dibrominated arene compounds through chelation effect.Keywords:acidic proton;non-cryogenic;arene;bromine–metal exchange
研究领域:
有机化学
·
杂环化学
✓ 已验证
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Yong Xiang,Chang-Yuan Cheng,Kang-Fei Lu,Wen-Cai Bai,Zhou-Xuan Zang,Li Xu,Guo-Ji Liu
Traditional metal–organic frameworks, characterized by their micropore-dominated structures, suffer from severe pore channel blockage during gold ion recovery due to the aggregation of gold nanoparticles, significantly reducing the utilization rate of adsorption sites. To address this issue, we developed hierarchically porous MOFs through ligand removal and metal exchange strategies, precisely installing adsorption sites within meso/macropores to effectively prevent pore obstruction by adsorbed-reduced gold particles. Subsequent Metal substitution further enhanced the material’s aqueous stability, enabling retention of 93 % adsorption capacity after 5 cycles while preserving the precisely engineered pore structure. The functionalized HP-MOF-5/DU achieves an ultrahigh Au(III) capacity of 1566 mg/g, rapid kinetics, and exceptional selectivity. Practical validation demonstrates 85 % gold recovery from real electronic waste leachates, with calcination yielding gold particles of 23.7 K purity. Through rational regulation of pore channel structures at adsorption sites, we have significantly enhanced the material’s Au(III) adsorption performance, pioneering a novel direction for the design of reducible metal-targeted adsorbents.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2023
·
IF 3.8
Zheng Yin,Yi-Biao Li,Ya-Nan Yu,Rou Huang,Shuai Yang,Xing-Yao Zhang,Li-Hui Cao
The obtaining of high porosity and understanding the dynamic pore responses to various inclusion guests represents one main focus in the functionalization of metal-organic frameworks (MOFs). A new solvothermally generated MOF of {(Me 2 NH 2 )[Ni 3 ( μ 3 OH)(tzba) 3 (H 2 O) 3 ]}·8DMF ( Ni 3− MOF , H 2 tzba = 4-(1H-tetrazol-5-yl)benzoic acid) processes negative charged, new triangular [Ni 3 ( μ 3 OH)(COO) 3 (tz) 3 (H 2 O) 3 ] node based, MIL-88-topology resembled framework, with high void fraction of 73.3%. While the introduction of equivalent Mn 2+ will greatly change the coordination assembly, leading to 2D (3,6)-grid layer of [Ni 1.4 Mn 1.6 (tzba) 3 (H 2 O) 6 ]·12DMF ( NiMn-MOF ) as the first example of synergistical construction of rare [M 2 (tz) 3 (H 2 O) 3 ] and [M(COO) 3 ] nodes. The 2D layers parallelly stacked in ABAB fashion through interlayer hydrogen bonding, and generated a neutral framework with high void fraction of 72.9% and 1D mesoporous hexagonal channels with diameter of 24.0 Å. The Ni 3− MOF is highly flexible and tends to close its pores after full guest removing, yet its gas accessible porosity is sensitive to residual guest in the pores and the porosity are fully reserved in organic solution phase to capture Methylene Blue and iodine. The inherent strong structure dynamic of Ni 3− MOF facilitates post-synthetic metal exchange of the Ni 2+ by Mn 2+ , Co 2+ , Cu 2+ and Cd 2+ , as well as the in-situ formation of amorphous Ni(OH) 2 electrocatalyst for dual water splitting with full recovery of costly organic ligands. For the NiMn-MOF , large gas accessible porosity with Langmuir surface area of 1052 m 2 g −1 , as well as guest dependent shrink-swell behavior was obtained. The NiMn-MOF is found to be an effective porous adsorbent to capture the iodine in either solution or gaseous phase, with uptake up to 2.4 mol iodine per mol of MOFs and capture of iodine with concentration lower to 5.0 × 10 −5 mol/L.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Ya-Nan Yu,Shuai Yang,Xi-Yao Li,Rou Huang,Jie Zhou,Zheng Yin
Ligand with mixed-groups contributes to the construction of special structure motif with novel properties, yet it is challenging to understand and regulate the competitive coordination of different functional groups toward metal ions. Herein, the crystal engineering for MOF construction from two linear di-topic linkers of 4-(1H-tetrazol-5-yl)benzoic acid (H 2 tzba) and the longer 4′-(1H-tetrazol-5-yl)-[1,1′-biphenyl]-4-carboxylic acid (H 2 tzbba) featuring dual groups of phenyl-carboxylate and tetrazole, with three typical 3d metal ions (Mn 2+ , Fe 2+ and Zn 2+ ) were investigated. A series of five new MOFs, that are [Mn 3 (tzba) 3 (dmf) 4 ]·11dmf ( 1 , dmf = N ,N-Dimethylformamide), [Mn(tzba)(H 2 O)] ( 2 ), [Zn 2 (tzba) 2 (dmf)]·0.5dmf ( 3 ), [Fe 2 (tzba) 2 (dmf)]·0.5dmf ( 4 ) and [Zn 2 (tzbbz)(gac)(dmf) 2 ]·1.5dmf ( 5 ), were synthesized under solvothermal reactions. The modified solvent template and temperature effects lead to 3D framework of 1 (dmf solution under 433 K) with [Mn 3 (tz) 3 (COO) 3 ] nodes and 1D hexagonal channels, while the 2 (water solution under 373 K) posssesses compact pillared-layer motif from [Mn 2 (tz) 2 ] nodes. Under changed metal salt reactents but same solvent of dmf, the generated 3 and 4 have isoreticular and porous pillared-layer structure constituted of [M 2 (COO) 2 ] nodes. The use of tzbba coupled with a crucial auxiliary ligand of glycollic acid, leads to 5 as porous pillared-layer MOFs with 1D rounded channels. The porous flexible skeleton of 1 constructed from [Mn 3 ] node with four coordinated dmf facilitates post-synthetic metal exchange of the Mn 2+ by radius similar metal ions following priority of Cu 2+ < Zn 2+ < Ni 2+ < Co 2+ , with maximum exchange percentage ranging from 17 % to 69 %. Time dependent ICP-AES analysis revealed the quite wide feasible solvents for post-synthetic metal exchange, as well as the fine control on substituting degree based on soaking temperature and time. Particularly, the compatible introduce of four different metal ions support the potential of preparing bi-, tri-, tetra- and penta- metal MOF crystals, that can not be obtained by traditional solvothermal reactions.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
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