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Your search keyword '"Zhou, Hao‐Long"' showing total 164 results
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164 results on '"Zhou, Hao‐Long"'

11. Molecular Sieving of Propyne/Propylene by a Scalable Nanoporous Crystal with Confined Rotational Shutters.

Author

Wan, Jingmeng, Zhou, Hao‐Long, Hyeon‐Deuk, Kim, Chang, I‐Ya, Huang, Yuhang, Krishna, Rajamani, and Duan, Jingui

Subjects
*MOLECULAR sieves, *MOLECULAR size, *PROPENE, *POROUS polymers, *COORDINATION polymers, *ROTATIONAL motion
Abstract

Soft porous coordination polymers (PCPs) have the remarkable ability to recognize similar molecules as a result of their structural dynamics. However, their guest‐induced gate‐opening behaviors often lead to issues with selectivity and separation efficiency, as co‐adsorption is nearly unavoidable. Herein, we report a strategy of a confined‐rotational shutter, in which the rotation of pyridyl rings within the confined nanospace of a halogen‐bonded coordination framework (NTU‐88) creates a maximum aperture of 4.4 Å, which is very close to the molecular size of propyne (C3H4: 4.4 Å), but smaller than that of propylene (C3H6: 5.4 Å). This has been evidenced by crystallographic analyses and modelling calculations. The NTU‐88o (open phase of activated NTU‐88) demonstrates dedicated C3H4 adsorption, and thereby leads to a sieving separation of C3H4/C3H6 under ambient conditions. The integrated nature of high uptake ratio, considerable capacity, scalable synthesis, and good stability make NTU‐88 a promising candidate for the feasible removal of C3H4 from C3H4/C3H6 mixtures. In principle, this strategy holds high potential for extension to soft families, making it a powerful tool for optimizing materials that can tackle challenging separations with no co‐adsorption, while retaining the crucial aspect of high capacity. [ABSTRACT FROM AUTHOR]

Published
2023
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25. Dynamic Pendulum Effect of an Exceptionally Flexible Pillared‐Layer Metal‐Organic Framework†.

Author

Zhou, Hao‐Long, Bai, Jie, Tian, Xiao‐Yun, Mo, Zong‐Wen, and Chen, Xiao‐Ming

Subjects
*SMART materials, *METAL-organic frameworks, *X-ray diffraction, *PENDULUMS, *POROUS polymers, *COORDINATION polymers
Abstract

Main observation and conclusion: Magnifying the controllable directional motions of molecular machines to the macroscopic levels is a significant topic for chemists. Flexible metal–organic frameworks with long‐range order and responsive structural transformation under external stimuli may be an appropriate platform for achieving the target. By taking advantage of the single‐crystal to single‐crystal manner of soft porous crystals, we utilize single‐crystal X‐ray diffraction to directly observe the dynamic structural inversion of a new three‐fold interpenetrated pillared‐layer metal‐organic framework [Co(edba)(bpy)] (MCF‐83, H2edba = 4,4'‐(ethyne‐1,2‐diyl)dibenzoic acid, bpy = 4,4'‐bipyridine). More interestingly, the dynamic inversions of the pillars and layers are selectively guest‐controllable and independent, allowing precise control of the directional shape changes, which is the key of constructing intelligent materials to accomplish a complex task. The mechanism is further studied by combining the X‐ray diffraction analyses, sorption measurements and molecular simulations. [ABSTRACT FROM AUTHOR]

Published
2021
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26. Dynamic Pendulum Effect of an Exceptionally Flexible Pillared‐Layer Metal‐Organic Framework†.

Author

Zhou, Hao‐Long, Bai, Jie, Tian, Xiao‐Yun, Mo, Zong‐Wen, and Chen, Xiao‐Ming

Subjects
SMART materials, METAL-organic frameworks, X-ray diffraction, PENDULUMS, POROUS polymers, COORDINATION polymers
Abstract

Main observation and conclusion: Magnifying the controllable directional motions of molecular machines to the macroscopic levels is a significant topic for chemists. Flexible metal–organic frameworks with long‐range order and responsive structural transformation under external stimuli may be an appropriate platform for achieving the target. By taking advantage of the single‐crystal to single‐crystal manner of soft porous crystals, we utilize single‐crystal X‐ray diffraction to directly observe the dynamic structural inversion of a new three‐fold interpenetrated pillared‐layer metal‐organic framework [Co(edba)(bpy)] (MCF‐83, H2edba = 4,4'‐(ethyne‐1,2‐diyl)dibenzoic acid, bpy = 4,4'‐bipyridine). More interestingly, the dynamic inversions of the pillars and layers are selectively guest‐controllable and independent, allowing precise control of the directional shape changes, which is the key of constructing intelligent materials to accomplish a complex task. The mechanism is further studied by combining the X‐ray diffraction analyses, sorption measurements and molecular simulations. [ABSTRACT FROM AUTHOR]

Published
2021
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31. Tuning fluorocarbon adsorption in new isoreticular porous coordination frameworks for heat transformation applications† †Electronic supplementary information (ESI) available: Experimental section, PXRD patterns, crystallographic tables and characterization details, and X-ray crystallographic files in CIF format. CCDC 1031873 and 1031874. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc03985h Click here for additional data file. Click here for additional data file

Author

Lin, Rui-Biao, Li, Tai-Yang, Zhou, Hao-Long, He, Chun-Ting, Zhang, Jie-Peng, and Chen, Xiao-Ming

Subjects
Chemistry
Abstract

We report adsorption behaviors of a typical fluorocarbon R22 (CHClF2) in a new series of isoreticular porous coordination frameworks [Zn4O(bpz)2(ldc)]., Adsorption heat transformation is one of the most energy-efficient technologies, which relies much on the type and performance of the adsorbent–adsorbate pair. Here, we report adsorption behaviors of a typical fluorocarbon R22 (CHClF2) in a new series of isoreticular porous coordination polymers [Zn4O(bpz)2(ldc)], in which the typical Zn4O clusters are connected by hydrophobic 3,3′,5,5′-tetramethyl-4,4′-bipyrazolate (bpz2–) and different linear dicarboxylates (ldc2–) to form non-interpenetrated pcu networks with variable pore sizes, shapes, and volumes. Fluorocarbon sorption measurements of these materials revealed high R22 uptakes of 0.73–0.97 g g–1 (0.62–0.65 g cm–3) at 298 K and 1 bar and working capacities of 0.41–0.72 g g–1 (0.35–0.47 g cm–3) between 273 and 313 K at about 0.13, 0.11 and 0.52 bar, respectively, as well as very large diffusion coefficients of 5.1–7.3 × 10–7 cm2 s–1. Noteworthily, the R22 sorption performance can be dramatically improved by subtle modification of the pore size and shape, demonstrating porous coordination polymer–fluorocarbon as a promising adsorbent–adsorbate pair for heat transformation applications.

Published
2015

45. Controlling flexibility of metal–organic frameworks.

Author

Zhang, Jie-Peng, Zhou, Hao-Long, Zhou, Dong-Dong, Liao, Pei-Qin, and Chen, Xiao-Ming

Subjects
*FLEXIBILITY (Mechanics), *METAL-organic frameworks, *COORDINATION polymers
Abstract

Framework flexibility is one of the most important characteristics of metal–organic frameworks (MOFs), which is not only interesting, but also useful for a variety of applications. Designing, tailoring or controlling framework flexibility of MOFs is much more difficult than for static structural features such as the framework topology and pore size/shape. Nevertheless, with in-depth understanding of the relationship between framework flexibility and the host framework structure, guest loading and other aspects such as the crystal size/morphology and external physical environment, some strategies have been developed for controlling the flexibility of MOFs and the corresponding properties, which are summarized and discussed in this review. [ABSTRACT FROM AUTHOR]

Published
2018
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49. Direct synthesis of an aliphatic amine functionalized metal–organic framework for efficient CO2 removal and CH4 purification.

Author

Huang, Ning-Yu, Mo, Zong-Wen, Li, Lu-Jian, Xu, Wei-Jian, Zhou, Hao-Long, Zhou, Dong-Dong, Liao, Pei-Qin, Zhang, Jie-Peng, and Chen, Xiao-Ming

Subjects
AMINES, METAL-organic frameworks
Abstract

Porous materials bearing free aliphatic amine groups are powerful adsorbents for carbon dioxide but generally have to be synthesized by complicated, multi-step post-synthetic modification methods due to the high activity of these functional groups. We report a crystal-engineering strategy for such metal–organic frameworks. Reactions of Zn(ii) ion with diversified coordination modes and bis(4-carboxy-benzyl)amine (H2bcba) with a secondary aliphatic amine bridge at different temperatures yielded a pair of isomeric frameworks with very similar framework structures but distinctly different local structures, namely α-[Zn(bcba)] (MCF-51 or α-Zn) with all amino groups coordinated and β-[Zn(bcba)] (MCF-52 or β-Zn) with uncoordinated amino groups. Single-component gas adsorption and CO2/CH4 mixture breakthrough experiments at ambient conditions showed that, the CO2 adsorption ability and CH4 purification performances of β-Zn, in terms of CO2 adsorption enthalpy (42 kJ mol−1), CO2/CH4 selectivity (32) and CH4 purity/productivity (1.49 mmol g−1 at 99.999%+), are much higher than those of α-Zn (CO2 adsorption enthalpy of 17 kJ mol−1, CO2/CH4 selectivity of 2.9 and CH4 purity/productivity of 0.088 mmol g−1 at 99%+). [ABSTRACT FROM AUTHOR]

Published
2018
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