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. 2024 Jan 23;6(2):666–673. doi: 10.1021/acsmaterialslett.3c01520

Insight into the Gas-Induced Phase Transformations in a 2D Switching Coordination Network via Coincident Gas Sorption and In Situ PXRD

Shi-Qiang Wang ‡,*, Volodymyr Bon §, Shaza Darwish ⊥, Shao-Min Wang ∥, Qing-Yuan Yang ∥, Zhengtao Xu ‡,*, Stefan Kaskel §,*, Michael J Zaworotko ⊥,*
PMCID: PMC10848331  PMID: 38333599

Abstract

graphic file with name tz3c01520_0006.jpg

Switching coordination networks (CNs) that reversibly transform between narrow or closed pore (cp) and large pore (lp) phases, though fewer than their rigid counterparts, offer opportunities for sorption-related applications. However, their structural transformations and switching mechanisms remain underexplored at the molecular level. In this study, we conducted a systematic investigation into a 2D switching CN, [Ni(bpy)2(NCS)2]n, sql-1-Ni-NCS (1 = bpy = 4,4′-bipyridine), using coincident gas sorption and in situ powder X-ray diffraction (PXRD) under low-temperature conditions. Gas adsorption measurements revealed that C2H4 (169 K) and C2H6 (185 K) exhibited single-step type F–IVs sorption isotherms with sorption uptakes of around 180–185 cm3 g–1, equivalent to four sorbate molecules per formula unit. Furthermore, parallel in situ PXRD experiments provided insight into sorbate-dependent phase switching during the sorption process. Specifically, CO2 sorption induced single-step phase switching (path I) solely between cp and lp phases consistent with the observed single-step type F–IVs sorption isotherm. By contrast, intermediate pore (ip) phases emerged during C2H4 and C2H6 desorption as well as C3H6 adsorption, although they remained undetectable in the sorption isotherms. To our knowledge, such a cp-lp-ip-cp transformation (path II) induced by C2H4/6 and accompanied by single-step type F–IVs sorption isotherms represents a novel type of phase transition mechanism in switching CNs. By virtue of Rietveld refinements and molecular simulations, we elucidated that the phase transformations are governed by cooperative local and global structural changes involving NCS– ligand reorientation, bpy ligand twist and rotation, cavity edge (Ni-bpy-Ni) deformation, and interlayer expansion and sliding.

Flexible metal–organic frameworks (FMOFs) or “third generation” porous coordination polymers/networks (PCPs/PCNs) have attracted increasing attention thanks to their structural flexibility which can be stimulus-induced.1−7 This phenomenon could enable applications such as gas storage and separation, to name a few,8−13 in the context of the “age of gas”.14 A characteristic of FMOFs is that they tend to exhibit S-shaped or “stepped” sorption isotherms concomitant with guest-induced structural transformations.15−17 A small yet important and growing subset of FMOFs is switching coordination networks (CNs) that undergo extreme guest-induced structural transformations between their “closed pore”, cp, nonporous and “large pore”, lp, porous phases, thereby featuring such stepped or type F–IV sorption isotherms.18 Switching CNs could offer higher working capacity, selectivity, and better thermal management than rigid sorbents with type I sorption isotherms.19−24

On the other hand, the structural flexibility of switching CNs also poses challenges for molecular-level structural elucidation that is crucial for understanding the underlying host–guest interactions and switching mechanisms. Switching CNs typically undergo phase transformations between their as-synthesized lp and activated cp phases (path I, Scheme 1a). In some instances, one or more intermediate pore (ip) phases that are partially open can exist during desorption (path II, Scheme 1b), adsorption (path III, Scheme 1c) or both processes (path IV, Scheme 1d). The resulting type F–IV gas sorption isotherms that reflect such phase transformations can be subcategorized into single-step profile (type F–IVs), multistep profile (type F–IVm), or combinations thereof (type F–IVsm: single-step adsorption with multistep desorption; type F–IVms: multistep adsorption with single-step desorption), as illustrated in Scheme 1. Measurement of gas sorption isotherms is therefore a general approach for monitoring and classifying phase transformations in switching CNs, based mainly on the number of sorption steps/plateaus and their corresponding sorption uptakes.

Scheme 1. Possible Structural Evolution Paths for 2D Switching CNs Induced by Sorbates/Guest Molecules (G, red balls) with Each Phase Stage Reflected As a Plateau in the Corresponding Type F–IV Sorption Isotherms.

Scheme 1

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Solid line/arrow: adsorption process; dashed line/arrow: desorption process.

However, relying solely on sorption isotherms can sometimes yield incomplete or even misleading insight into the phase transformations of switching CNs. This is because their sorption profile can be influenced by various extrinsic factors such as the test temperature/pressure and specific sorbate being studied.17,18,25 For example, initial studies on ELM-11 suggested a single-step phase transformation as indicated by CO2 sorption isotherms (type F–IVs) measured at ambient temperature and pressure.26 Nevertheless, further investigation revealed that its full scope of phase transformations includes three sorption steps, as evidenced by CO2 sorption data (type F–IVm) collected at 195 K or under high pressure (Figure S1a).27 For DUT-8(Ni), it is perhaps counterintuitive that C2H6 and C2H4 exhibited two-step phase transformation with the formation of ip phases while N2, CO2, and n-butane sorption resulted in a single-step transformation, even though their sorption isotherms all exhibit single-step type F–IVs profiles.28 These examples demonstrate the complexity of switching mechanisms and underscore a need for advanced in situ characterization techniques to monitor the structural evolution of switching CNs during gas sorption.29

In this context, integrating gas sorption measurement with in situ powder X-ray diffraction (PXRD) is considered one of the most direct approaches to observe structural changes during the entire gas adsorption/desorption process. While gas-loaded PXRD is not uncommon for FMOFs or switching CNs,26,27,30−41 it usually has to be guided by ex situ gas sorption isotherms measured beforehand. This asynchronous approach may introduce uncertainty regarding the accuracy and consistency. Recent advancements in coincident gas sorption and in situ PXRD techniques have effectively addressed this issue as demonstrated by several successful studies,28,42−47 thereby enhancing our overall understanding of phase switching mechanisms and facilitating the custom design of the next generation of switching CNs. This prompted us to investigate a prototypical 2D switching CN with a square lattice (sql) topology through coincident gas sorption and in situ PXRD, complemented by Rietveld refinements and molecular simulations.

2D sql CNs with general formula [M(L)2(A)2]n (M = divalent metal cation, L = ditopic linker ligand, A = axial counteranion) are modular from a crystal engineering perspective48−51 and exemplify the “node and linker” design strategy proposed by Hoskins and Robson over three decades ago.52,53 The first reported sorption study for 2D switching sql CNs was conducted on [Cu(bpy)2(BF4)2] (bpy = 4,4′-bipyridine), ELM-11, which was observed to exhibit single (type F–IVs) or multistep (type F–IVm) sorption isotherms (Scheme 1a, d) induced by gases such as N2, Ar, CO2, C2H2 and n-butane.26,27,33,43,54−58 Recently, we studied the sorption properties of three previously known sql CNs [M(bpy)2(NCS)2]n (M = Fe, Co, or Ni),59−65 sql-1-M-NCS, which are closely related to the ELM platform. CO2 sorption for sql-1-M-NCS resulted in single-step type F–IVs isotherms (Scheme 1a) and the switching pressures were found to be metal-ion controlled with the Ni version being the “softest”.59,61 It was later reported that sql-1-Ni-NCS exhibited even lower switching pressure and higher sorption uptake for C2H2 than for CO2.62

These findings prompted us to further study the adsorbate effect of nine gases on sql-1-Ni-NCS (Figure S2).64 It was observed that the sorption of C2H4 and C2H6 at 195 K exhibited switching behavior, but their uptakes did not reach saturation even at 113 kPa. In addition, sorption of C3H6 (propylene) and C3H8 (propane) at 273 K showed negligible uptake, while the C3H4 (propyne) sorption exhibited a rare type of F–IVsm sorption isotherm (Scheme 1b) with a saturation uptake of 138 cm3 g–1 that matches its CO2 uptake. We anticipated that lower temperature could favor C2H4/6 and C3H6/8 sorption,66,67 and through coincident gas sorption and in situ PXRD, we aim herein to address several open questions: (a) whether C2H4 and C2H6 sorption can reach saturation; (b) whether C3H6 and C3H8 can induce the phase switching; (c) whether intermediate phases exist during the structural transitions; (d) last, but not least, how the host structure responds to the different gas molecules, i.e., the underlying switching mechanisms.

sql-1-Ni-NCS was prepared by heating its 1D chain CP precursor, {[Ni(bpy)(NCS)2(H2O)2]·bpy}n, that can be obtained by water slurry method (see the Supporting Information for details).61 It is sustained by Ni(II) ions coordinated equatorially to two types of bpy linker ligands (half are coplanar, half are twisted) with terminal NCS– ligands occupying the axial positions. The interlayer distance is 4.5 Å (Figure 1a), the shortest among bpy-based sql CNs,68 and the effective dimension of the square cavity is approximately 7.5 Å × 7.5 Å (Figure 1b), suitable for accommodating small guest molecules. However, the cavity void is blocked by the interdigitated NCS– ligands and sql-1-Ni-NCS is therefore a cp structure. Thermogravimetric analysis (TGA) and water vapor sorption studies revealed that sql-1-Ni-NCS maintains its thermal stability up to 180 °C and, unlike its hydrophilic analogue ELM-11, sql-1-Ni-NCS is hydrophobic.61 It remains stable even after storage for four years, as confirmed by PXRD (Figure S3).

Figure 1.

Figure 1

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(a, b) Crystal structures of sql-1-Ni-NCS. (c) Gas sorption isotherms for sql-1-Ni-NCS.

For coincident gas sorption and in situ PXRD experiments, we investigated five gaseous sorbates on sql-1-Ni-NCS at their sublimation/boiling point temperatures (Figure 1c): CO2 (195 K); C2H4 (169 K); C2H6 (185 K); C3H6 (225 K); and C3H8 (231 K). The 195 K CO2 sorption isotherm matched well with our previous results,61 verifying the reliability and consistency of the in situ gas sorption/PXRD setup used in this study. Interestingly, the 169 K C2H4 sorption exhibited a similar trend to the previously reported 195 K C2H2 sorption isotherms (Figure S4).62 It plateaued with 185 cm3 g–1 uptake at around 60 kPa, corresponding to four C2H4 molecules per formula unit (denoted hereafter as sql-1-Ni-NCS·4C2H4). Similarly, the 185 K C2H6 sorption almost reached saturation with around 180 cm3 g–1 uptake at 95 kPa, corresponding to nearly four C2H6 molecules per formula unit (denoted hereafter as sql-1-Ni-NCS·4C2H6). We note that neither C2H4 (169 K) nor C2H6 (185 K) sorption is fully desorbed at the final data points of 0.95 and 5.2 kPa, respectively, owing to the sorption program parameters. Nevertheless, our previous study indicates that elevating the temperature to 195 K results in complete desorption of C2H4 and C2H6 at around 10 kPa (Figure S2). On the other hand, while the 231 K C3H8 sorption did not display apparent switching until 1 bar, the 225 K C3H6 sorption started to switch at around 80 kPa even though it did not reach a plateau at 95 kPa. These results highlight the significant influence of temperature can have on switching CNs, as was the case for ELM-11.26,27

The parallel in situ PXRD measurements that we conducted provide further insight into the structural evolution of sql-1-Ni-NCS (Figure 2). For example, in situ PXRD patterns (Figure 2d) indicate that during CO2 adsorption sql-1-Ni-NCS remained as a cp phase until 10 kPa (region: 1–3) and, before reaching the lp phase at around 40 kPa (region: 7–10), it entered a coexisting cp + lp phase between 10–40 kPa (region: 4–6). The CO2 desorption branch followed the reverse pathway: lp (region: 10-i-v); coexisting lp + cp (region: vi-vii); cp (region: vii). These profiles suggest that only two phases, cp (sql-1-Ni-NCS) and lp (sql-1-Ni-NCS·3CO2), exist during the CO2 sorption. In contrast, only two phases, cp (sql-1-Ni-NCS) and lp (sql-1-Ni-NCS·4C2H4/6), were observed during C2H4 and C2H6 adsorption (Figure S5), ip phases appeared during desorption, for example, in region v for C2H4 and vi for C2H6 (Figure 2e, f). The ip phase is not directly discernible from the C2H4/6 desorption branches as no substep plateau was observed in the sorption isotherms. The remaining uptake of around 92 cm3 g–1 corresponds to two C2H4 or C2H6 molecules per formula unit (denoted hereafter as sql-1-Ni-NCS·2C2H4/6). Furthermore, in situ PXRD patterns revealed coexisting cp and ip during C3H6 adsorption (Figure S6) and that the C3H6-loaded ip is structurally similar to sql-1-Ni-NCS·2C2H4/6 (Figure S7). Lastly, no structural change was observed during C3H8 sorption, which is consistent with its minimal uptake (Figure S8).

Figure 2.

Figure 2

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Coincident gas sorption and in situ PXRD for (a, d) CO2 at 195 K; (b, e) C2H4 at 169 K; and (c, f) C2H6 at 185 K.

In order to obtain structural information on sql-1-Ni-NCS during various gas sorption processes, ab initio indexing, structural modeling and Rietveld refinement (Figures S9, S10) were applied to determine the crystal structures of sql-1-Ni-NCS·4C2H4/6 (lp) and sql-1-Ni-NCS·2C2H4/6 (ip). The crystallographic data reveal that both the C2H4/6-loaded lp and ip phases maintained the same monoclinic C2/c space group as the cp and the CO2-loaded lp phases (Table S1). While the [NiN6] octahedral geometry is consistent for cp, ip, and lp phases, there are variations in the orientation of NCS– ligands toward Ni(II) (∠Ni–N–CS angles) and the torsion angle of the pyridyl rings (Figure 3 and Table S2). The ∠Ni–N–CS angles (Figures 1a and 3a–c) fall within the range of 140.8–169.5° and the bpy torsion angles (Figures 1b and 3d–f) lie between 54.7 and 82.0° for the cp, ip, and lp phases, with angle differences being up to 28.7° and 27.3°, respectively. The dihedral angles between the coplanar bpy ligand and the layer plane (Figure S11) vary from 62.1° in cp to 90.0°, 86.6°, and 87.8° in lp (CO2), lp (C2H4/6), and ip (C2H4/6), respectively, demonstrating the rotational flexibility of the bpy ligands. The ∠Ni–Ni–Ni angles (Figure 1b and 3d–f) transition from 76.4° (rhombic shape) in cp to around 90.0° (square shape) in ip and lp. The global structural changes reflected at the layer level is that the wavelike fashion of the coplanar bpy ligands (∠Ni–Ni–Ni = 152.8°) in cp transforms into a linear arrangement in the guest-loaded phases, exemplified by the CO2-loaded lp (Figure S12). Additionally, the interlayer distances (Figures 1a and 3a–c) increase from 4.5 Å in cp to 5.4 Å in lp (CO2), and further to 6.3 Å in lp (C2H4/6) with a slight reduction to 6.2 Å in ip (C2H4/6). Such interlayer expansion is accompanied by concurrent layer sliding. For instance, the stacked layers in the cp phase exhibit a shift of 3/8 of the repeating unit, which is reduced to 1/5 in the lp (C2H4/6) phase (Figure S13). This is primarily attributed to the intercalation of adsorbates into the interlayer space, as suggested by molecular simulation results (Figures S14–17).

Figure 3.

Figure 3

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Comparison of crystal structures of *a, d) sql-1-Ni-NCS·3CO2 (lp); *b, e) sql-1-NCS 4C2H4/6 (lp); and *c, f) sql-1-NCS 2C2H4/6 (ip).

Utilizing both previously reported and newly determined crystal structural information, along with the in situ gas-loaded PXRD data collected in this study, we can understand the changes in PXRD peaks that occur during gas adsorption. For instance, the peak at 2θ = 19.9° is characteristic for the cp phase and originates from the (202) plane of sql-1-Ni-NCS which lies parallel to the network planes (Figure S18a). Consequently, it is understandable that this peak disappears with expansion of the adjacent layers. Additionally, a peak at 2θ = 8.2° emerges in the lp phase due to interlayer expansion and sliding. Specifically, it arises from the (002) plane of sql-1-Ni-NCS·4C2H4/6, intersecting vertically with the bpy ligands (coplanar ones) of each layer (Figure S18b).

Structural comparison of previously reported sql-1-M-NCS·xG with a variety of adsorbates (Table S3) reveals the stoichiometric ratio (x) of G: M can be 2, 3, or 4 and guest-induced volume expansion ranges from 23.5–114.9%, allowing for classification of five distinct phase types, A to E (Figure 4).64 Although x is 3 for the CO2-loaded phase,61 sql-1-Ni-NCS·3CO2, it belongs to type A with a low volume expansion (23.5%) comparable to that of a MeOH-loaded phase (sql-1-Fe-NCS·3MeOH) but smaller than that of a CS2-loaded phase (sql-1-Fe-NCS·3CS2).69 This suggests that the adsorbate size can play a role in regulating the degree of interlayer expansion. Whereas C2H2 shares a similar kinetic diameter and molecular geometry with CO2, x is 4 for the C2H2-loaded phase (sql-1-Ni-NCS·4C2H2).62 The volume expansion of sql-1-Ni-NCS·4C2H2 (40.5%) is larger than that of sql-1-Ni-NCS·3CO2 and belongs to type B. C2H4 and C2H6 possess kinetic diameters larger than those of C2H2, enabling sql-1-Ni-NCS·4C2H4/6 to exhibit even larger volume expansion (44.8%, type C). This volume expansion is relatively small compared to those of C3H6O (acetone) and CHCl3-loaded phases of type D69,70 and is much smaller than that of xylene (C8H10)-loaded phases (type E) which hold the current benchmark for interlayer expansion among bpy-based sql CNs.60 With respect to the C2H4/6-loaded ip, it has almost the same unit-cell volume as the type B structure sql-1-Ni-NCS·4C2H2.

Figure 4.

Figure 4

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Unit-cell volume (Z value normalized to 4) distribution of sql-1-M-NCS·xG.

When comparing the gas sorption behaviors of sql-1-Ni-NCS with its analogous ELM-11 (sql-1-Cu-BF4), some notable differences are observed despite their comparable cavity sizes (∼7.0–7.5 Å) and interlayer distances (∼4.5 Å). First, sql-1-Ni-NCS displayed significantly higher gate opening pressure than ELM-11 under the same measurement conditions.27,61 Second, sql-1-Ni-NCS exhibited only one CO2-loaded phase (sql-1-Ni-NCS·3CO2) while ELM-11 exhibited three distinct phases: ELM-11·2CO2, ELM-11·3CO2, and ELM-11·6CO2 (Figure S1a).27 Additionally, ELM-11 has been reported to have four C2H2-loaded phases with x = 1, 2, 6, 8, respectively (Figure S1b–d).58 In terms of structural evolution during gas sorption, prior research revealed that no additional ip phase lies between ELM-11 and ELM-11·2CO2 or ELM-11·2C4H10,43 despite the observation of ELM-11·1C2H2 between ELM-11 and ELM-11·2C2H2 in the C2H2 sorption isotherms.57,58

Gas molecules larger than CO2, like n-butane (C4H10), resulted in larger volume expansion for ELM-11 (Table S4) despite having the same ratio (x = 2).43 This trend aligns with the behavior of sql-1-M-NCS with respect to the sorption of C2H2, C2H4/6, C3H6O, CHCl3, and C8H10 (x = 4).60,62,69,70 However, it does not necessarily apply to 3D switching CNs such as DUT-8(Ni) and MIL-53(Fe).28,37 This discrepancy might be attributed to the degree of dimensional flexibility inherent in FMOFs.71,72 The presence of relatively weak interactions, such as van der Waals forces, between adjacent layers in 2D switching CNs implies high flexibility and adaptability. This feature allows 2D switching CNs to accommodate various guest molecules with different sizes and shapes through induced-fit inclusion and claylike intercalation, as illustrated in Figures S19–S23.

In summary, we detail gas-induced phase switching in a 2D sql CN, sql-1-Ni-NCS, using coincident gas sorption and in situ PXRD. Thanks to the low temperature gas sorption measurements of C2H4 (169 K), C2H6 (185 K), C3H6 (225 K), and C3H8 (231 K), we addressed the first two questions outlined earlier: (a) C2H4 and C2H6 sorption can reach or nearly reach saturation plateau (185 cm3 g–1) before 1 bar at their boiling point temperatures, although both sorption isotherms were previously found to be incomplete at 195 K and around 1.1 bar;64 (b) C3H6 can induce partial phase switching while C3H8 failed to do so before reaching 1 bar at their boiling point temperatures. Subsequently, in situ PXRD and Rietveld refinements allowed us to answer the remaining questions: (c) There was no ip phase observed during CO2 sorption. However, ip phases were detected during C2H4/6 desorption and C3H6 adsorption, although it was not discernible from their respective sorption isotherms; d) In order to accommodate different gas molecules, the structure of sql-1-Ni-NCS undergoes local and global structural changes including NCS ligand reorientation, bpy ligand twist and rotation, cavity edge (Ni-bpy-Ni) deformation, and interlayer expansion.

The discovery of intermediate phases and the structure determination of each phase within sql-1-Ni-NCS emphasize the importance of collecting in situ PXRD data throughout the entire gas sorption profile to gain insight into the full landscape of structural transformations.29,73 The elucidation of the adsorbate-dependency of the phase transition path and volume expansion could provide useful guidance for utilizing switching CNs in various sorption-related applications, such as gas storage, hydrocarbon separation, and sensing. Given that sql-1-Ni-NCS belongs to a broad family of sql CNs with numerous options for M (metal cation), L (linker ligand), A (counteranion), and G (guest adsorbate),18 further sorption studies on such switching CNs are therefore in progress.

Acknowledgments

M.J.Z. gratefully acknowledges the support of Science Foundation Ireland (16/IA/4624) and the Irish Research Council (IRCLA/2019/167). V.B. and S.K. acknowledge the German Federal Ministry of Research and Education (Projects No. 05K22OD1 and 05K22OD2) for financial support. Z.X. acknowledges a startup fund from the Agency for Science, Technology and Research (SC25/22-119116).

Supporting Information Available

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsmaterialslett.3c01520.

  • Experimental details, PXRD patterns, and gas sorption isotherms (PDF)

Author Contributions

† These authors contributed equally. All authors have approved the final version of the manuscript.

The authors declare no competing financial interest.

Supplementary Material

tz3c01520_si_001.pdf (2.2MB, pdf)
tz3c01520_si_002.cif (3.5KB, cif)
tz3c01520_si_003.cif (3.6KB, cif)
tz3c01520_si_004.cif (3.8KB, cif)
tz3c01520_si_005.cif (4.1KB, cif)

References

  1. Kitagawa S.; Kondo M. Functional micropore chemistry of crystalline metal complex-assembled compounds. Bull. Chem. Soc. Jpn. 1998, 71, 1739–1753. 10.1246/bcsj.71.1739. [DOI] [Google Scholar]
  2. Kitagawa S.; Kitaura R.; Noro S. i. Functional porous coordination polymers. Angew. Chem., Int. Ed. 2004, 43, 2334–2375. 10.1002/anie.200300610. [DOI] [PubMed] [Google Scholar]
  3. Uemura K.; Matsuda R.; Kitagawa S. Flexible microporous coordination polymers. J. Solid State Chem. 2005, 178, 2420–2429. 10.1016/j.jssc.2005.05.036. [DOI] [Google Scholar]
  4. Fletcher A. J.; Thomas K. M.; Rosseinsky M. J. Flexibility in metal-organic framework materials: Impact on sorption properties. J. Solid State Chem. 2005, 178, 2491–2510. 10.1016/j.jssc.2005.05.019. [DOI] [Google Scholar]
  5. Férey G.; Serre C. Large breathing effects in three-dimensional porous hybrid matter: facts, analyses, rules and consequences. Chem. Soc. Rev. 2009, 38, 1380–1399. 10.1039/b804302g. [DOI] [PubMed] [Google Scholar]
  6. Schneemann A.; Bon V.; Schwedler I.; Senkovska I.; Kaskel S.; Fischer R. A. Flexible metal-organic frameworks. Chem. Soc. Rev. 2014, 43, 6062–6096. 10.1039/C4CS00101J. [DOI] [PubMed] [Google Scholar]
  7. Dong J.; Wee V.; Zhao D. Stimuli-responsive metal-organic frameworks enabled by intrinsic molecular motion. Nat. Mater. 2022, 21, 1334–1340. 10.1038/s41563-022-01317-y. [DOI] [PubMed] [Google Scholar]
  8. Chang Z.; Yang D.-H.; Xu J.; Hu T.-L.; Bu X.-H. Flexible Metal-Organic Frameworks: Recent Advances and Potential Applications. Adv. Mater. 2015, 27, 5432–5441. 10.1002/adma.201501523. [DOI] [PubMed] [Google Scholar]
  9. Lee J. H.; Jeoung S.; Chung Y. G.; Moon H. R. Elucidation of flexible metal-organic frameworks: Research progresses and recent developments. Coord. Chem. Rev. 2019, 389, 161–188. 10.1016/j.ccr.2019.03.008. [DOI] [Google Scholar]
  10. Qian B.; Chang Z.; Bu X. H. Functionalized Dynamic Metal-Organic Frameworks as Smart Switches for Sensing and Adsorption Applications. Top Curr. Chem. 2020, 378, 5. 10.1007/s41061-019-0271-2. [DOI] [PubMed] [Google Scholar]
  11. Peh S. B.; Karmakar A.; Zhao D. Multiscale Design of Flexible Metal-Organic Frameworks. Trends Chem. 2020, 2, 199–213. 10.1016/j.trechm.2019.10.007. [DOI] [Google Scholar]
  12. Bigdeli F.; Lollar C. T.; Morsali A.; Zhou H.-C. Switching in Metal-Organic Frameworks. Angew. Chem., Int. Ed. 2020, 59, 4652–4669. 10.1002/anie.201900666. [DOI] [PubMed] [Google Scholar]
  13. Zhou D.-D.; Zhang J.-P. On the Role of Flexibility for Adsorptive Separation. Acc. Chem. Res. 2022, 55, 2966–2977. 10.1021/acs.accounts.2c00418. [DOI] [PubMed] [Google Scholar]
  14. Kitagawa S. Porous Materials and the Age of Gas. Angew. Chem., Int. Ed. 2015, 54, 10686–10687. 10.1002/anie.201503835. [DOI] [PubMed] [Google Scholar]
  15. Horike S.; Shimomura S.; Kitagawa S. Soft porous crystals. Nat. Chem. 2009, 1, 695–704. 10.1038/nchem.444. [DOI] [PubMed] [Google Scholar]
  16. Krause S.; Hosono N.; Kitagawa S. Chemistry of Soft Porous Crystals: Structural Dynamics and Gas Adsorption Properties. Angew. Chem., Int. Ed. 2020, 59, 15325–15341. 10.1002/anie.202004535. [DOI] [PubMed] [Google Scholar]
  17. Senkovska I.; Bon V.; Abylgazina L.; Mendt M.; Berger J.; Kieslich G.; Petkov P.; Luiz Fiorio J.; Joswig J.-O.; Heine T.; et al. Understanding MOF Flexibility: An Analysis Focused on Pillared Layer MOFs as a Model System. Angew. Chem., Int. Ed. 2023, 62, e202218076 10.1002/anie.202218076. [DOI] [PubMed] [Google Scholar]
  18. Wang S.-Q.; Mukherjee S.; Zaworotko M. J. Spiers Memorial Lecture: Coordination networks that switch between nonporous and porous structures: an emerging class of soft porous crystals. Faraday Discuss. 2021, 231, 9–50. 10.1039/D1FD00037C. [DOI] [PubMed] [Google Scholar]
  19. Mason J. A.; Oktawiec J.; Taylor M. K.; Hudson M. R.; Rodriguez J.; Bachman J. E.; Gonzalez M. I.; Cervellino A.; Guagliardi A.; Brown C. M.; Llewellyn P. L.; Masciocchi N.; Long J. R. Methane storage in flexible metal-organic frameworks with intrinsic thermal management. Nature 2015, 527, 357–361. 10.1038/nature15732. [DOI] [PubMed] [Google Scholar]
  20. Li L.; Wang Y.; Yang J.; Wang X.; Li J. Targeted capture and pressure/temperature responsive separation in flexible metal-organic frameworks. J. Mater. Chem. A 2015, 3, 22574–22583. 10.1039/C5TA00679A. [DOI] [Google Scholar]
  21. Hiraide S.; Tanaka H.; Ishikawa N.; Miyahara M. T. Intrinsic Thermal Management Capabilities of Flexible Metal-Organic Frameworks for Carbon Dioxide Separation and Capture. ACS Appl. Mater. Interfaces 2017, 9, 41066–41077. 10.1021/acsami.7b13771. [DOI] [PubMed] [Google Scholar]
  22. Yang Q.-Y.; Lama P.; Sen S.; Lusi M.; Chen K.-J.; Gao W.-Y.; Shivanna M.; Pham T.; Hosono N.; Kusaka S.; et al. Reversible Switching between Highly Porous and Nonporous Phases of an Interpenetrated Diamondoid Coordination Network That Exhibits Gate-Opening at Methane Storage Pressures. Angew. Chem., Int. Ed. 2018, 57, 5684–5689. 10.1002/anie.201800820. [DOI] [PubMed] [Google Scholar]
  23. Dong Q.; Zhang X.; Liu S.; Lin R. B.; Guo Y.; Ma Y.; Yonezu A.; Krishna R.; Liu G.; Duan J.; Matsuda R.; Jin W.; Chen B. Tuning Gate-Opening of a Flexible Metal-Organic Framework for Ternary Gas Sieving Separation. Angew. Chem., Int. Ed. 2020, 59, 22756–22762. 10.1002/anie.202011802. [DOI] [PubMed] [Google Scholar]
  24. Bonneau M.; Lavenn C.; Zheng J.-J.; Legrand A.; Ogawa T.; Sugimoto K.; Coudert F.-X.; Reau R.; Sakaki S.; Otake K.-i.; Kitagawa S. Tunable acetylene sorption by flexible catenated metal-organic frameworks. Nat. Chem. 2022, 14, 816–822. 10.1038/s41557-022-00928-x. [DOI] [PubMed] [Google Scholar]
  25. Zhang J.-P.; Zhou H.-L.; Zhou D.-D.; Liao P.-Q.; Chen X.-M. Controlling flexibility of metal-organic frameworks. Nat. Sci. Rev. 2018, 5, 907–919. 10.1093/nsr/nwx127. [DOI] [Google Scholar]
  26. Kondo A.; Noguchi H.; Ohnishi S.; Kajiro H.; Tohdoh A.; Hattori Y.; Xu W.-C.; Tanaka H.; Kanoh H.; Kaneko K. Novel Expansion/Shrinkage Modulation of 2D Layered MOF Triggered by Clathrate Formation with CO2 Molecules. Nano Lett. 2006, 6, 2581–2584. 10.1021/nl062032b. [DOI] [PubMed] [Google Scholar]
  27. Ichikawa M.; Kondo A.; Noguchi H.; Kojima N.; Ohba T.; Kajiro H.; Hattori Y.; Kanoh H. Double-Step Gate Phenomenon in CO2 Sorption of an Elastic Layer-Structured MOF. Langmuir 2016, 32, 9722–9726. 10.1021/acs.langmuir.6b02551. [DOI] [PubMed] [Google Scholar]
  28. Bon V.; Klein N.; Senkovska I.; Heerwig A.; Getzschmann J.; Wallacher D.; Zizak I.; Brzhezinskaya M.; Mueller U.; Kaskel S. Exceptional adsorption-induced cluster and network deformation in the flexible metal-organic framework DUT-8(Ni) observed by in situ X-ray diffraction and EXAFS. Phys. Chem. Chem. Phys. 2015, 17, 17471–17479. 10.1039/C5CP02180D. [DOI] [PubMed] [Google Scholar]
  29. Bon V.; Brunner E.; Pöppl A.; Kaskel S. Unraveling Structure and Dynamics in Porous Frameworks via Advanced In Situ Characterization Techniques. Adv. Funct. Mater. 2020, 30, 1907847. 10.1002/adfm.202070272. [DOI] [Google Scholar]
  30. Kitaura R.; Kitagawa S.; Kubota Y.; Kobayashi T. C.; Kindo K.; Mita Y.; Matsuo A.; Kobayashi M.; Chang H.-C.; Ozawa T. C.; Suzuki M.; Sakata M.; Takata M. Formation of a One-Dimensional Array of Oxygen in a Microporous Metal-Organic Solid. Science 2002, 298, 2358–2361. 10.1126/science.1078481. [DOI] [PubMed] [Google Scholar]
  31. Matsuda R.; Kitaura R.; Kitagawa S.; Kubota Y.; Belosludov R. V.; Kobayashi T. C.; Sakamoto H.; Chiba T.; Takata M.; Kawazoe Y.; Mita Y. Highly controlled acetylene accommodation in a metal-organic microporous material. Nature 2005, 436, 238–241. 10.1038/nature03852. [DOI] [PubMed] [Google Scholar]
  32. Kondo A.; Noguchi H.; Carlucci L.; Proserpio D. M.; Ciani G.; Kajiro H.; Ohba T.; Kanoh H.; Kaneko K. Double-Step Gas Sorption of a Two-Dimensional Metal-Organic Framework. J. Am. Chem. Soc. 2007, 129, 12362–1236. 10.1021/ja073568h. [DOI] [PubMed] [Google Scholar]
  33. Hiraide S.; Tanaka H.; Miyahara M. T. Understanding gate adsorption behaviour of CO2 on elastic layer-structured metal-organic framework-11. Dalton Trans. 2016, 45, 4193–4202. 10.1039/C5DT03476K. [DOI] [PubMed] [Google Scholar]
  34. Serre C.; Bourrelly S.; Vimont A.; Ramsahye N. A.; Maurin G.; Llewellyn P. L.; Daturi M.; Filinchuk Y.; Leynaud O.; Barnes P.; Ferey G. An explanation for the very large breathing effect of a metal-organic framework during CO2 adsorption. Adv. Mater. 2007, 19, 2246–2251. 10.1002/adma.200602645. [DOI] [Google Scholar]
  35. Llewellyn P. L.; Maurin G.; Devic T.; Loera-Serna S.; Rosenbach N.; Serre C.; Bourrelly S.; Horcajada P.; Filinchuk Y.; Ferey G. Prediction of the Conditions for Breathing of Metal Organic Framework Materials Using a Combination of X-ray Powder Diffraction, Microcalorimetry, and Molecular Simulation. J. Am. Chem. Soc. 2008, 130, 12808–12814. 10.1021/ja803899q. [DOI] [PubMed] [Google Scholar]
  36. Hamon L.; Llewellyn P. L.; Devic T.; Ghoufi A.; Clet G.; Guillerm V.; Pirngruber G. D.; Maurin G.; Serre C.; Driver G.; van Beek W.; Jolimaitre E.; Vimont A.; Daturi M.; Ferey G. Co-adsorption and Separation of CO2-CH4 Mixtures in the Highly Flexible MIL-53(Cr) MOF. J. Am. Chem. Soc. 2009, 131, 17490–17499. 10.1021/ja907556q. [DOI] [PubMed] [Google Scholar]
  37. Llewellyn P. L.; Horcajada P.; Maurin G.; Devic T.; Rosenbach N.; Bourrelly S.; Serre C.; Vincent D.; Loera-Serna S.; Filinchuk Y.; Ferey G. Complex adsorption of short linear alkanes in the flexible metal-organic-framework MIL-53(Fe). J. Am. Chem. Soc. 2009, 131, 13002–13008. 10.1021/ja902740r. [DOI] [PubMed] [Google Scholar]
  38. Couck S.; Gobechiya E.; Kirschhock C. E. A.; Serra-Crespo P.; Juan-Alcaniz J.; Martinez Joaristi A.; Stavitski E.; Gascon J.; Kapteijn F.; Baron G. V.; Denayer J. F. M. Adsorption and Separation of Light Gases on an Amino-Functionalized Metal-Organic Framework: An Adsorption and In Situ XRD Study. ChemSusChem 2012, 5, 740–750. 10.1002/cssc.201100378. [DOI] [PubMed] [Google Scholar]
  39. Devic T.; Salles F.; Bourrelly S.; Moulin B.; Maurin G.; Horcajada P.; Serre C.; Vimont A.; Lavalley J.-C.; Leclerc H.; Clet G.; Daturi M.; Llewellyn P. L.; Filinchuk Y.; Ferey G. Effect of the organic functionalization of flexible MOFs on the adsorption of CO2. J. Mater. Chem. 2012, 22, 10266–10273. 10.1039/c2jm15887f. [DOI] [Google Scholar]
  40. Zhu A.-X.; Yang Q.-Y.; Kumar A.; Crowley C.; Mukherjee S.; Chen K.-J.; Wang S.-Q.; O’Nolan D.; Shivanna M.; Zaworotko M. J. A Coordination Network That Reversibly Switches between Two Nonporous Polymorphs and a High Surface Area Porous Phase. J. Am. Chem. Soc. 2018, 140, 15572–15576. 10.1021/jacs.8b08642. [DOI] [PubMed] [Google Scholar]
  41. Lange M.; Kobalz M.; Bergmann J.; Lässig D.; Lincke J.; Möllmer J.; Möller A.; Hofmann J.; Krautscheid H.; Staudt R.; Gläser R. Structural flexibility of a copper-based metal-organic framework: sorption of C4-hydrocarbons and in situ XRD. J. Mater. Chem. A 2014, 2, 8075–8085. 10.1039/C3TA15331B. [DOI] [Google Scholar]
  42. Bureekaew S.; Sato H.; Matsuda R.; Kubota Y.; Hirose R.; Kim J.; Kato K.; Takata M.; Kitagawa S. Control of Interpenetration for Tuning Structural Flexibility Influences Sorption Properties. Angew. Chem., Int. Ed. 2010, 49, 7660–7664. 10.1002/anie.201002259. [DOI] [PubMed] [Google Scholar]
  43. Bon V.; Senkovska I.; Wallacher D.; Heerwig A.; Klein N.; Zizak I.; Feyerherm R.; Dudzik E.; Kaskel S. In situ monitoring of structural changes during the adsorption on flexible porous coordination polymers by X-ray powder diffraction: Instrumentation and experimental results. Microporous Mesoporous Mater. 2014, 188, 190–195. 10.1016/j.micromeso.2013.12.024. [DOI] [Google Scholar]
  44. Noro S.-i.; Mizutani J.; Hijikata Y.; Matsuda R.; Sato H.; Kitagawa S.; Sugimoto K.; Inubushi Y.; Kubo K.; Nakamura T. Porous coordination polymers with ubiquitous and biocompatible metals and a neutral bridging ligand. Nat. Commun. 2015, 6, 5851. 10.1038/ncomms6851. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Shivanna M.; Yang Q.-Y.; Bajpai A.; Sen S.; Hosono N.; Kusaka S.; Pham T.; Forrest K. A.; Space B.; Kitagawa S.; Zaworotko M. J. Readily accessible shape-memory effect in a porous interpenetrated coordination network. Sci. Adv. 2018, 4, eaaq1636 10.1126/sciadv.aaq1636. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Shivanna M.; Otake K.-i.; Song B.-Q.; van Wyk L. M.; Yang Q.-Y.; Kumar N.; Feldmann W. K.; Pham T.; Suepaul S.; Space B.; Barbour L. J.; Kitagawa S.; Zaworotko M. J. Benchmark Acetylene Binding Affinity and Separation through Induced Fit in a Flexible Hybrid Ultramicroporous Material. Angew. Chem., Int. Ed. 2021, 60, 20383–20390. 10.1002/anie.202106263. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Koupepidou K.; Nikolayenko V. I.; Sensharma D.; Bezrukov A. A.; Shivanna M.; Castell D. C.; Wang S.-Q.; Kumar N.; Otake K.-i.; Kitagawa S.; Zaworotko M. J. Control over Phase Transformations in a Family of Flexible Double Diamondoid Coordination Networks through Linker Ligand Substitution. Chem. Mater. 2023, 35, 3660–3670. 10.1021/acs.chemmater.3c00334. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Fujita M.; Kwon Y. J.; Washizu S.; Ogura K. Preparation, clathration ability, and catalysis of a two-dimensional square network material composed of cadmium (II) and 4, 4’-bipyridine. J. Am. Chem. Soc. 1994, 116, 1151–1152. 10.1021/ja00082a055. [DOI] [Google Scholar]
  49. Biradha K.; Hongo Y.; Fujita M. Open Square-Grid Coordination Polymers of the Dimensions 20 × 20 Å: Remarkably Stable and Crystalline Solids Even after Guest Removal. Angew. Chem., Int. Ed. 2000, 39, 3843–3845. . [DOI] [PubMed] [Google Scholar]
  50. Biradha K.; Mondal A.; Moulton B.; Zaworotko M. J. Coexisting covalent and non-covalent planar networks in the crystal structures of {[M(bipy)2(NO3)2]·arene}n (M = Ni, 1; Co, 2; arene = chlorobenzene, o-dichlorobenzene, benzene, nitrobenzene, toluene or anisole). J. Chem. Soc., Dalton Trans. 2000, 3837–3844. 10.1039/b003733h. [DOI] [Google Scholar]
  51. Kumar N.; Wang S.-Q.; Mukherjee S.; Bezrukov A. A.; Patyk-Kaźmierczak E.; O’Nolan D.; Kumar A.; Yu M.-H.; Chang Z.; Bu X.-H.; Zaworotko M. J. Crystal engineering of a rectangular sql coordination network to enable xylenes selectivity over ethylbenzene. Chem. Sci. 2020, 11, 6889–6895. 10.1039/D0SC02123G. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Hoskins B. F.; Robson R. Infinite polymeric frameworks consisting of three dimensionally linked rod-like segments. J. Am. Chem. Soc. 1989, 111, 5962–5964. 10.1021/ja00197a079. [DOI] [Google Scholar]
  53. Hoskins B. F.; Robson R. Design and construction of a new class of scaffolding-like materials comprising infinite polymeric frameworks of 3D-linked molecular rods. A reappraisal of the zinc cyanide and cadmium cyanide structures and the synthesis and structure of the diamond-related frameworks [N(CH3)4][CuIZnII(CN)4] and CuI[4,4’,4’’,4’’’-tetracyanotetraphenylmethane]BF4.xC6H5NO2. J. Am. Chem. Soc. 1990, 112, 1546–1554. 10.1021/ja00160a038. [DOI] [Google Scholar]
  54. Li D.; Kaneko K. Hydrogen bond-regulated microporous nature of copper complex-assembled microcrystals. Chem. Phys. Lett. 2001, 335, 50–56. 10.1016/S0009-2614(00)01419-6. [DOI] [Google Scholar]
  55. Kanoh H.; Kondo A.; Noguchi H.; Kajiro H.; Tohdoh A.; Hattori Y.; Xu W.-C.; Inoue M.; Sugiura T.; Morita K.; Tanaka H.; Ohba T.; Kaneko K. Elastic layer-structured metal organic frameworks (ELMs). J. Colloid Interface Sci. 2009, 334, 1–7. 10.1016/j.jcis.2009.03.020. [DOI] [PubMed] [Google Scholar]
  56. Kajiro H.; Kondo A.; Kaneko K.; Kanoh H. Flexible two-dimensional square-grid coordination polymers: structures and functions. Int. J. Mol. Sci. 2010, 11, 3803–3845. 10.3390/ijms11103803. [DOI] [PMC free article] [PubMed] [Google Scholar]
  57. Li L.; Krishna R.; Wang Y.; Wang X.; Yang J.; Li J. Flexible Metal-Organic Frameworks with Discriminatory Gate-Opening Effect for the Separation of Acetylene from Ethylene/Acetylene Mixtures. Eur. J. Inorg. Chem. 2016, 2016, 4457–4462. 10.1002/ejic.201600182. [DOI] [Google Scholar]
  58. Wang S.-Q.; Meng X.-Q.; Vandichel M.; Darwish S.; Chang Z.; Bu X.-H.; Zaworotko M. J. High Working Capacity Acetylene Storage at Ambient Temperature Enabled by a Switching Adsorbent Layered Material. ACS Appl. Mater. Interfaces 2021, 13, 23877–23883. 10.1021/acsami.1c06241. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Wang S.-Q.; Yang Q.-Y.; Mukherjee S.; O’Nolan D.; Patyk-Kazmierczak E.; Chen K.-J.; Shivanna M.; Murray C.; Tang C. C.; Zaworotko M. J. Recyclable switching between nonporous and porous phases of a square lattice (sql) topology coordination network. Chem. Commun. 2018, 54, 7042–7045. 10.1039/C8CC03838D. [DOI] [PubMed] [Google Scholar]
  60. Wang S.-Q.; Mukherjee S.; Patyk-Kazḿierczak E.; Darwish S.; Bajpai A.; Yang Q.-Y.; Zaworotko M. J. Highly Selective, High-Capacity Separation of o-Xylene from C8 Aromatics by a Switching Adsorbent Layered Material. Angew. Chem., Int. Ed. 2019, 58, 6630–6634. 10.1002/anie.201901198. [DOI] [PubMed] [Google Scholar]
  61. Wang S.-Q.; Darwish S.; Sensharma D.; Zaworotko M. J. Tuning the switching pressure in square lattice coordination networks by metal cation substitution. Mater. Adv. 2022, 3, 1240–1247. 10.1039/D1MA00785H. [DOI] [Google Scholar]
  62. Wang S.-Q.; Darwish S.; Meng X.-Q.; Chang Z.; Bu X.-H.; Zaworotko M. J. Acetylene storage performance of [Ni(4,4’-bipyridine)2(NCS)2]n, a switching square lattice coordination network. Chem. Commun. 2022, 58, 1534–1537. 10.1039/D1CC06638B. [DOI] [PubMed] [Google Scholar]
  63. Patyk-Kaźmierczak E.; Kaźmierczak M.; Wang S.-Q.; Zaworotko M. J. Pressure-Induced Structural Effects in the Square Lattice (sql) Topology Coordination Network sql-1-Co-NCS·4OX. Cryst. Growth Des. 2023, 23, 2055–2064. 10.1021/acs.cgd.2c00982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Wang S.-Q.; Darwish S.; Zaworotko M. J. Adsorbate-dependent phase switching in the square lattice topology coordination network [Ni(4,4’-bipyridine)2(NCS)2]n. Chem. Commun. 2023, 59, 559–562. 10.1039/D2CC06549E. [DOI] [PubMed] [Google Scholar]
  65. Wang S.-Q.; Darwish S.; Zaworotko M. J. The impact of solution vs. slurry vs. mechanochemical syntheses upon the sorption performance of a 2D switching coordination network. Inorg. Chem. Front. 2023, 10, 3821–3827. 10.1039/D3QI00391D. [DOI] [Google Scholar]
  66. He Y.-P.; Tan Y.-X.; Zhang J. Tuning a layer to a pillared-layer metal-organic framework for adsorption and separation of light hydrocarbons. Chem. Commun. 2013, 49, 11323–11325. 10.1039/c3cc47286h. [DOI] [PubMed] [Google Scholar]
  67. Li H.-Z.; Li Q.-H.; Yao M.; Han Y.-P.; Otake K.-i.; Kitagawa S.; Wang F.; Zhang J. Metal-Organic Framework with Structural Flexibility Responding Specifically to Acetylene and Its Adsorption Behavior. ACS Appl. Mater. Interfaces 2022, 14, 45451–45457. 10.1021/acsami.2c13599. [DOI] [PubMed] [Google Scholar]
  68. Zhang Y.; Jianmin L.; Wei D.; Nishiura M.; Imamoto T. The Most Effective Packing of Layers: Synthesis and Structure of [Ni(4,4’-bipyridine)2(NCS)2]n. Chem. Lett. 1999, 28, 195–196. 10.1246/cl.1999.195. [DOI] [Google Scholar]
  69. Adams C. J.; Real J. A.; Waddington R. E. The two-dimensional iron (ii)-thiocyanate-4,4’-bipyridine coordination network. CrystEngComm 2010, 12, 3547–3553. 10.1039/c0ce00149j. [DOI] [Google Scholar]
  70. Adams C. J.; Muñoz M. C.; Waddington R. E.; Real J. A. Cooperative Spin Transition in the Two-Dimensional Coordination Polymer [Fe(4,4’-bipyridine)2(NCX)2]·4CHCl3 (X= S, Se). Inorg. Chem. 2011, 50, 10633–10642. 10.1021/ic200932w. [DOI] [PubMed] [Google Scholar]
  71. Kitagawa S.; Uemura K. Dynamic porous properties of coordination polymers inspired by hydrogen bonds. Chem. Soc. Rev. 2005, 34, 109–119. 10.1039/b313997m. [DOI] [PubMed] [Google Scholar]
  72. Murdock C. R.; Hughes B. C.; Lu Z.; Jenkins D. M. Approaches for synthesizing breathing MOFs by exploiting dimensional rigidity. Coord. Chem. Rev. 2014, 258–259, 119–136. 10.1016/j.ccr.2013.09.006. [DOI] [Google Scholar]
  73. Cho H. S.; Tanaka H.; Miyasaka K.; Terasaki O. How to Directly Observe and Understand Adsorption: Gas Adsorption Crystallography. Acc. Mater. Res. 2023, 4, 668–680. 10.1021/accountsmr.3c00052. [DOI] [Google Scholar]

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Supplementary Materials

tz3c01520_si_001.pdf (2.2MB, pdf)
tz3c01520_si_002.cif (3.5KB, cif)
tz3c01520_si_003.cif (3.6KB, cif)
tz3c01520_si_004.cif (3.8KB, cif)
tz3c01520_si_005.cif (4.1KB, cif)

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