Dramatic improvement of stability by in situ linker cyclization of a metal–organic framework

Hou, Yun-Long; Li, Mu-Qing; Cheng, Shan; Diao, Yingxue; Vilela, Filipe; He, Yonghe; Xu, Zhengtao

doi:10.1039/c8cc05225e

Cited by 24 publications

(30 citation statements)

References 77 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[181] In addition, ditopic linkers with different sizes and functional groups can be used to construct bcu Zr-MOFs. [182][183][184][185] Different structures can be obtained using ditopic V-shaped ligands. For example, Li and co-workers reported two twofold interpenetrated 3D pcu-type networks based on long and angular ligands, BUT-66 and BUT-67.…”

Section: Zr-mofs Based On Ditopic Linkersmentioning

confidence: 99%

See 1 more Smart Citation

Metal–Organic Frameworks Based on Group 3 and 4 Metals

et al. 2020

View full text Add to dashboard Cite

Metal-organic frameworks (MOFs), a class of porous crystalline framework materials, are linked by strong bonds between inorganic and organic building blocks. [1-3] In the past two decades, MOFs have rapidly grown as a star material due to their exceptional performance in areas such as storage, separation and catalysis. [4] The outstanding performance of MOFs in applications benefits from their intrinsically porous structures and highly tunable pore environment. [5-7] The creation and modification of pore space with optimized size, functionality and diversity can be precisely tuned at the molecular level by rationally designing building blocks and synthetic procedures. [8,9] The diversity of MOFs can be enriched by expanding the library of organic linkers with varying lengths, geometries, and functional groups. [10] Additionally, very diverse metal cations are applied to MOF synthesis, ranging from monovalent (Ag + , Cu + , etc.), divalent (Mg 2+ , Fe 2+ , Co 2+ , Ni 2+ , etc.), trivalent (Al 3+ , Sc 3+ , V 3+ , Cr 3+ , etc.), to tetravalent (Ti 4+ , Zr 4+ , Hf 4+ , etc.) cations. [11] In this review, we mainly focus on MOFs with group 3 and 4 metals, including Y, lanthanides (Ln, from La to Lu), actinides (An, from Ac to Lr), Ti, and Zr (Figure 1). Group 3 metal cations are generally found in the oxidation state of +3 in the MOF structures, while group 4 metal cations mainly exist in the oxidation state of +4, leading to the formation of much stronger coordination bonds with carboxylates. [12] Therefore, group 4 metal-based MOFs (M IV-MOFs) generally have enhanced stability compared with MOFs constructed from metals of group 3 and other groups. This series of MOFs stands out because the involved metals can generally coordinate with carboxylates to form frameworks with strong coordination bonds, according to the Pearson's hard/soft acid/base principle, where group 3 and 4 metal cations are regarded as hard acids while carboxylate ligands are hard bases. [11] One remarkable feature of MOFs with group 3 and 4 metals is that they generally can form phases containing M 6 O 8 (M = Y, Ln, An, Zr and Hf) clusters, regardless of their atomic numbers, charges and radius. This series of M 6-based MOFs is best represented by UiO series such as UiO-66 with fcu topology. [13] Under different synthetic conditions, UiO-66(M, M = An, Zr and Hf) constructed from [M 6 (μ 3-O) 4 (μ 3-OH) 4 ] clusters and linear carboxylates can be obtained, while UiO-66(M, M = Y, Ln) is assembled from Metal-organic frameworks (MOFs) based on group 3 and 4 metals are considered as the most promising MOFs for varying practical applications including water adsorption, carbon conversion, and biomedical applications. The relatively strong coordination bonds and versatile coordination modes within these MOFs endow the framework with high chemical stability, diverse structures and topologies, and interesting properties and functions. Herein, the significant progress made on this series of MOFs since 2018 is summarized and an update on the current status an...

show abstract

Section: Zr-mofs Based On Ditopic Linkersmentioning

confidence: 99%

“…[ 181 ] In addition, ditopic linkers with different sizes and functional groups can be used to construct bcu Zr‐MOFs. [ 182–185 ]…”

Section: Mofs Based On Zr (Group 4 Metal)mentioning

confidence: 99%

Metal–Organic Frameworks Based on Group 3 and 4 Metals

et al. 2020

View full text Add to dashboard Cite

show abstract

“…20 When the MOF solids are heated above 200°C, the contiguous alkyne units undergo extensive thermocyclization. While the tetratopic-linked, more rigid Zr-Tc8tBu lost crystallinity upon thermocyclization, 21 the linear, more supple Zr-Dc4ms afforded an ordered polycrystalline black covalent solid at 320°C, 22 even with decarboxylation of the linker units (as indicated by solid state 13 C NMR). Above 320°C, however, the crystalline order of the cyclized product quickly degraded.…”

Section: Onto 3d Graphenesmentioning

confidence: 99%

Uniting Form and Function, Stability and Reactivity in Open Framework Materials

2020

Chemistry Letters

Self Cite

View full text Add to dashboard Cite

After his BS (1996) at Peking University, Xu had a plan for organic chemistry, only to join Stephen Lee's group at Michigan and receive a PhD from Cornell for works on coordination networks (MOFs). After a postdoc with David Mitzi (IBM, 200103), he moved to George Washington University as an assistant professor to open his work on sulfur-equipped MOFs.As life would have it, he then started anew in Hong Kong (from 2005), and became a professor in 2015. His group has an interest in bridging the two worlds of coordination and covalent frameworks.

show abstract

“…Solution 1 H NMR spectrum (CDCl3, 400 MHz; Inset: a local region between a) δ = 6.9 and 7.7 ppm; b) δ = 0.7 and 2.6 ppm) for characterizing the molecules emitted from the thermal treatment (NiL1-ac heated at 300 °C for 2 hours to convert into NiL1-300). The assignment of the signals are also presented, i.e., the singlet (δ, 2.12) from CH3SCH3 9 , the singlet (δ, 7.36) from benzene; the singlet (δ, 2.49) and multiple (δ, 7.36 ~ 7.14) from (methylthio)benzene. Further study on the singlet at δ = 0.88, 1.26, 2.01 observed in the 1 H NMR spectrum is however needed.…”

Section: Figure S8mentioning

confidence: 99%

“…The resultant nanographene components enhance the electroactive properties of the porous hosts, achieving hydrogen evolution reaction (HER) activity that rivals topical nickel/palladium-enabled materials.Recently, we have studied cascade cyclization of alkyne units built into the linker molecules of metal-organic frameworks (e.g., the relatively stable Zr 4+ -carboxyl systems). [1][2][3] The thermally triggered cyclization (e.g., above 300 °C) leads to cross-linked, partially graphitized products that feature enhanced polarizability (e.g., black in color) and chemical stability. Topically, this line of work bears on the endeavors to assemble polarizable, large-π molecules into MOF scaffold to enhance photophysical and electronic properties [4][5][6][7][8][9][10][11][12][13][14][15][16] .…”

mentioning

confidence: 99%

Linker Deficiency, Aromatic Ring Fusion and Electrocatalysis in a Porous Ni8 Pyrazolate Network

Hu¹,

Deng²,

Zhang³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

The cruciform linker molecule here features two designer functions: the pyrazole donors for framework construction, and the vicinal alkynyl units for benzannulation to form nanographene units into the Ni8-pyrazolate scaffold. Unlike the full 12 connections of the Ni8(OH)4(H2O)2 clusters in other Ni8-pyrazolate networks, significant linker deficiency was observed here, leaving about half of the Ni(II) sites capped by acetate ligands, which can be potentially removed to open the metal sites for reactivity. The crystalline Ni8-pyrazolate scaffold also retains the crystalline order even after thermal treatments (up to 300 °C) that served to partially graphitizes the neighboring alkyne units. The resultant nanographene components enhance the electroactive properties of the porous hosts, achieving hydrogen evolution reaction (HER) activity that rivals topical nickel/palladium-enabled materials.

show abstract

Dramatic improvement of stability by in situ linker cyclization of a metal–organic framework

Cited by 24 publications

References 77 publications

Metal–Organic Frameworks Based on Group 3 and 4 Metals

Metal–Organic Frameworks Based on Group 3 and 4 Metals

Uniting Form and Function, Stability and Reactivity in Open Framework Materials

Linker Deficiency, Aromatic Ring Fusion and Electrocatalysis in a Porous Ni8 Pyrazolate Network

Contact Info

Product

Resources

About