Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2018 Nov 28;10(1):16-33.
doi: 10.1039/c8sc04475a. eCollection 2019 Jan 7.

Proton Transfer in Hydrogen-Bonded Degenerate Systems of Water and Ammonia in Metal-Organic Frameworks

Affiliations
Free PMC article
Review

Proton Transfer in Hydrogen-Bonded Degenerate Systems of Water and Ammonia in Metal-Organic Frameworks

Dae-Woon Lim et al. Chem Sci. .
Free PMC article

Abstract

Porous crystalline metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) are emerging as a new class of proton conductors with numerous investigations. Some of the MOFs exhibit an excellent proton-conducting performance (higher than 10-2 S cm-1) originating from the interesting hydrogen(H)-bonding networks with guest molecules, where the conducting medium plays a crucial role. In the overwhelming majority of MOFs, the conducting medium is H2O because of its degenerate conjugate acid-base system (H3O+ + H2O ⇔ H2O + H3O+ or OH- + H2O ⇔ H2O + OH-) and the efficient H-bonding ability through two proton donor and two acceptor sites with a tetrahedral geometry. Considering the systematic molecular similarity to water, ammonia (NH3; NH4 + + NH3 ⇔ NH3 + NH4 +) is promising as the next proton-conducting medium. In addition, there are few reports on NH3-mediated proton conductivity in MOFs. In this perspective, we provide overviews of the degenerate water (hydronium or hydroxide)- or ammonia (ammonium)-mediated proton conduction system, the design strategies for proton-conductive MOFs, and the conduction mechanisms.

Figures

Scheme 1
Scheme 1. Schematic representation of proton transfer in water- and ammonia-conducting media with degenerate systems.
Fig. 1
Fig. 1. Classification of proton sources in metal–organic frameworks: (a and b) intrinsic proton sources and (c) extrinsic proton sources.
Fig. 2
Fig. 2. (a) Honeycomb layer structure of (NH4)2(H2adp)[Zn2(ox)3]·3H2O. (b) Perspective view along the b-axis. Guest molecules are omitted. (c) H-bond arrangements of –COOH, H2O, and NH4+ in the interlayer. H bonds are shown as blue dotted lines. The colors of red, green, gray, and blue correspond to O, N, C, and Zn atoms, respectively. Reproduced from ref. 47 with permission from American Chemical Society, Copyright 2009.
Fig. 3
Fig. 3. Crystal structures of dihydrate and anhydrate phases. Honeycomb layer structure of (a) dihydrate and (c) anhydrate. The layered structure of (b) dihydrate and (d) anhydrate. Red, gray, green, and blue colors correspond to O, C, N, and Zn atoms, respectively. Reproduced from ref. 48 with permission from American Chemical Society, Copyright 2014.
Fig. 4
Fig. 4. Representation of H-bonding networks in (a) trihydrate, (b) dihydrate, and (c) anhydrate. Reproduced from ref. 48 with permission from American Chemical Society, Copyright 2014.
Fig. 5
Fig. 5. The crystal structure of {NR3(CH2COOH)}–[MCr(ox)3nH2O. (a) Representation of the coordination geometry around MnII and CrIII, (b) the honeycomb layer structure, and (c) stacking view along the layers. Reproduced from ref. 49 with permission from American Chemical Society, Copyright 2012.
Fig. 6
Fig. 6. Humidity dependence of the proton conductivity at 298 K. The blue, green, red, purple, and gray colors correspond to the proton conductivity of Me–FeCr, Et–MnCr, Bu–FeCr, Bu–MnCr, and NBu4, respectively. Reproduced from ref. 49 with permission from American Chemical Society, Copyright 2012.
Fig. 7
Fig. 7. Schematic view of the basic framework structure of MIL-53.
Fig. 8
Fig. 8. (a) Crystal structure of UiO-66. (b) Scheme of the post-synthetic modification of UiO-66(SH)2 to introduce sulfonic acid groups.
Fig. 9
Fig. 9. Schematic illustration of the migration of OH ions with water solvent. Reproduced from ref. 51 with permission from Nature Publishing Group, Copyright 2002.
Fig. 10
Fig. 10. Representation of the crystal structure of ZIF-8 (ref. 53) and a schematic image of salt inclusion. (a) Cage and (b) 3-D porous SOD structures of ZIF-8. (c) Schematic view of the preparation procedure for NBu4-ZIF-8-OH. Reproduced from ref. 52 with permission from American Chemical Society, Copyright 2014.
Fig. 11
Fig. 11. (a) Crystal structure of [Ni2(m-pymca)3]OH·nH2O along the channel. (b) Schematic representation of a cationic MOF with an anionic supramolecular chain of hydroxide anions and water molecules inside the MOF pore for efficient hydroxide ion conduction. Reproduced from ref. 55 with permission from Royal Society of Chemistry, Copyright 2016.
Fig. 12
Fig. 12. Ionic transport pathway of FJU-66[EVIm]OH. (a) Packing view of FJU-66[EVIm]OH along the a direction. (b) Packing view of the available water pathways in FJU-66 along the a and b directions. (c) Possible supramolecular chain formed by OH anions and water molecules inside the channel of FJU-66 for efficient OH ion conduction. Reproduced from ref. 56 with permission from American Chemical Society, Copyright 2017.
Fig. 13
Fig. 13. (a) MOF structures based on H2BTDD (left) and H2BBTA (right) ligands. (b) Brunauer–Emmett–Teller (BET) surface area change after NH3 exposure. Reproduced from ref. 66 with permission from American Chemical Society, Copyright 2018.
Fig. 14
Fig. 14. Comparison of H-bonding networks by ion substitution. (a) (NH4)2(H2adp)[Zn2(ox)3]·3H2O. (b) K2(H2adp)[Zn2(ox)3]·3H2O. Reproduced from ref. 71 with permission from American Chemical Society, Copyright 2014.
Fig. 15
Fig. 15. (a) Structure of (NH4)4[MnCr2(ox)6]·4H2O. NH4+ counterion and H2O guest molecules are represented as a sphere. Red, green, gray, cyan, and blue correspond to oxygen, chromium, carbon, manganese, and nitrogen atoms, respectively. (b) Cole–Cole semicircle plot at 295 K and 96% RH. (c) RH dependence of σ for (NH4)4[MnCr2(ox)6]·4H2O at 295 K. Reproduced from ref. 72 with permission from American Chemical Society, Copyright 2011.
Fig. 16
Fig. 16. b-axis view (a-axis horizontal) of the crystal structures of Ca-PiPhtA-I (a) and Ca-PiPhtA-II (b) showing the slightly different conformation of the 1-D channels along the c axis. (c) Plot of the complex impedance plane of Ca-PiPhtA compounds at 24 °C and 98% RH. (d) Arrhenius plots vs. T–1 from 10 to 24 °C. Reproduced from ref. 73 with permission from American Chemical Society, Copyright 2014.
Fig. 17
Fig. 17. 1-D channels with water molecules in (a) {[Co3(m-ClPhIDC)2(H2O)6]·2H2O}n (1) and (b) {[Co3(p-ClPhHIDC)3(H2O)3]·6H2O}n (2). Red spheres represent O atoms in water, and green dots present H-bonding networks. Reproduced from ref. 74 with permission from American Chemical Society, Copyright 2017.
Fig. 18
Fig. 18. NH3 adsorption–desorption isotherm, structure of NH3@MIL-53(Al) derivatives, and proton conductivity. (a) NH3 adsorption–desorption profiles at 298 K and 100 kPa. The different colors represent MIL-53(Al) derivatives (–(COOH)2, red; –NH2, green; –OH, pink; –H, blue). (b and c) Crystal structures of NH3@MIL-53(Al)–(COOH)2 and (e and f) NH3@MIL-53(Al)–(NH2). (d) NH3 pressure dependence of proton conductivity in MIL-53(Al) derivatives. Reproduced from ref. 76 abiding by the terms of the license from Chemrxive, Copyright 2018.
Fig. 19
Fig. 19. 2-D intensity maps obtained by neutron powder diffraction on IRIS for (a) (NH4)2(adp)[Zn2(ox)3]·3H2O and (b) K2(adp)[Zn2(ox)3]·3H2O. The intensity is given on a logarithmic scale. The white dashed line represents each transition temperature. Reproduced with permission from ref. 77 with permission from Royal Society of Chemistry, Copyright 2014.
Fig. 20
Fig. 20. (a) QENS profiles of (NH4)2(adp)[Zn2(ox)3]·3H2O obtained by using AGNES, IRIS, and HFBS spectrometers. (b) Arrhenius plot for the relaxation times of (NH4)2(adp)[Zn2(ox)3]·3H2O (filled symbols) and K2(adp)[Zn2(ox)3]·3H2O (open symbols) at Qav = 1.25 Å–1. (c) EISF of (NH4)2(adp)[Zn2(ox)3]·3H2O for the L1 mode measured by AGNES (left) and the L2 mode measured by IRIS (right). Solid curves represent the calculated EISF based on several model functions. Reproduced from ref. 77 with permission from Royal Society of Chemistry, Copyright 2014.
Fig. 21
Fig. 21. (a) The temperature dependence 2H NMR of ND3 confined in the framework with three main components marked by arrows. (b) Line shape analysis for the ND3-saturated framework at 183 K: (top) experimental (black solid line) and full simulation (red dashed line); 8-times magnified spectra–experimental (black solid line) and full simulation (red dashed line); (bottom) simulation deconvolution into two main fractions: I (anisotropic) and II (isotropic); simulation deconvolution of the anisotropic fraction: Ia and Ib. (c) Dynamic motion of Ia: fast axial rotation, Ib: restricted libration, and II: isotropic reorientation including internal rotation, local Td jump and jump diffusion. (d and e) Spin–relaxation time (T1 and T2) for I and II. Reproduced from ref. 76 abiding by the terms of the license from Chemrxive, Copyright 2018.
Fig. 22
Fig. 22. (a) Free energy profiles of proton transfer in MIL-53(Cr) calculated as a function of the MS-EVB reaction coordinate qreac = c12c22. The results for bulk water are taken from ref. 78. (b) Continuous time correlation function, Cc(t). (c) Pseudocontinuous time correlation function, Cpc(t). All results for MIL-53(Cr) were obtained at T = 300 K as a function of the number of water molecules (N) adsorbed per unit cell. (d) Proton diffusion coefficient, DCEC, (e) water diffusion coefficient, DWAT, and (f) water orientational relaxation time, τ2, calculated MIL-53(Cr) as a function of both temperature and number of water molecules (N) adsorbed per unit cell. The dashed lines indicate the corresponding values calculated for bulk water at 300 K. Reproduced from ref. 79 with permission from American Chemical Society, Copyright 2012.
Fig. 23
Fig. 23. (a) Arrhenius plot of Ds for protons (squares) and water molecules (circles) in the fully hydrated UiO-66(Zr)–(CO2H)2: QENS (open symbols) and aMS-EVB3-MD simulations (full symbols). (b) Illustration of simulation result for the water (blue)-mediated pathway with proton (orange) along the tetrahedral (A) and octahedral cages (B) of UiO-66(Zr)-(CO2H)2 at 450 K. Reproduced from ref. 81 with permission from Wiley-VCH, Copyright 2016.
Fig. 24
Fig. 24. (a) Self-diffusivities of water (empty symbols and dashed lines) and the center of excess charge (full symbols and solid lines) simulated at 400 K in UiO-66(Zr)–(CO2H)2 as a function of water loading defined as the number of water molecules (nH2O) per unit cell (uc). (b) Residence time of water molecules in the cages of UiO-66(Zr)–(CO2H)2 averaged over aMS-EVB3 trajectories obtained at 400 K as a function of water loading. (c) Simulated distribution of water in the tetrahedral (from 1 to 8) and octahedral (from 9 to 12) cages of UiO-66(Zr)–(CO2H)2 at 400 K. Reproduced from ref. 84 with permission from American Chemical Society, Copyright 2017.
None
Dae-Woon Lim
None
Masaaki Sadakiyo
None
Hiroshi Kitagawa

Similar articles

See all similar articles

Cited by 2 articles

References

    1. Kreuer K. D. Chem. Mater. 1996;8:610–641.
    1. Alberti G., Casciola M., Costantino U., Leonardi M. Solid State Ionics. 1984;14:289–295.
    1. Iwahara H. Solid State Ionics. 1996:86–88.
    1. Skou E., Kauranen P., Hentschel J. Solid State Ionics. 1997;97:333–337.
    1. Mauritz K. A., Moore R. B. Chem. Rev. 2004;104:4535–4586. - PubMed
Feedback