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Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX
Robust Porphyrin-Spaced Zirconium Pyrogallate Frameworks with High Proton Conduction Er-Xia Chen,†,‡ Gang Xu,† and Qipu Lin*,† †
Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China University of Chinese Academy of Sciences, Beijing 100049, China
‡
Inorg. Chem. Downloaded from pubs.acs.org by WEBSTER UNIV on 03/01/19. For personal use only.
S Supporting Information *
reported a two-dimensional phospate-assisted zirconium phosphonate layered complex with excellent proton-transfer capacity because of the presence of abundant exposed acid sites,38 while a one-dimensional zirconium phosphonate chained version (termed SZ-5),39 developed by Wang and coworkers, just showed moderate proton conductivity. Apart from these oxygenated acids, phenols remain little explored as proton sources for augmenting proton diffusion, and the phenolatebased coordination frameworks are also fairly rare.40 It is noted that the utility of polyphenols for MOF fabrication helps to boost the concentration of acid points, largely ascribed to their high H-to-O ratio (=1.0, doubling that of carboxyls). Coupled with another crucial issue, chemical inertia, phenolate MOFs have been recognized as promising platforms for improved proton transport. Indeed, lots of semiquinone-based (or oxalate, quite similar to the extreme version of tetraoxolene) MOFs have been extensively studied for conductance, notwithstanding typically in less robust assemblies.18,40−43 Especially, a catecholate MOF, Fe-CAT-5,42 was reported to have proton conductivity of up to 5.0 × 10−2 S cm−1, rivaling that of Nafion. With abreast trihydroxyls, pyrogallates would be appealing analogues to be used as linkers to coordinate with oxophilic metal cations, like Zr4+, to form ultrastable structures and also probably offer the promise of accessing a high content of proton carriers. We recently developed a series of acid- and base-resistant zirconium pyrogallic frameworks composed of infinite zirconium(4+) oxide chains linked via porphyrin spacers, namely, ZrPP-n [n = 1 for Zr2(THPP)·(solvent), n = 2 for Zr2(THBPP)·(solvent), where THPP = 5,10,15,20-tetrakis(3,4,5-trihydroxyphenyl)porphyrin, THBPP = 5,10,15,20tetrakis(3,4,5-trihydroxybiphenyl)porphyrin, and solvent = dimethylamine and water; Figure 1],44 which exhibited not only high CO2 trapping capability but also efficient visible-lightdriven reduction of CO2 into CO. These zirconium polyphenolate MOFs have a strongly enhanced chemical robustness compared to commonly known carboxylate zirconium-based types, as shown by their inertia in saturated NaOH aqueous solution. Beyond their hydrolytic stability, ZrPP-n possess acidic Zr4+-bonded phenol groups on the porphyrinic linker (as previously evidenced by 13C solid-state NMR and IR spectroscopy) and confine solvent molecules (protonated dimethylamine and water) in the pores,44 which hint at the potential of ZrPP-n to act as water-mediated proton-conducting materials.
ABSTRACT: An isoreticular family of zirconium polyphenolate networks (ZrPP-n, n = 1 and 2), bridged by porphyrinic macrocycles in an eclipsed arrangement, have excellent stability toward water, especially strong basic media of saturated NaOH aqueous solution. Endowed with spatial alignment of protic sites, viz., partially protonated phenols of acidity enhanced by coordination to Zr4+, along with guest dimethylamine cations, the newly synthesized ZrPP-n reveal exceptional conductivity (8.0 × 10−3 and 4.2 × 10−3 S cm−1, for n = 1 and 2, respectively, pelleted sample, under 98% relative humidity at 25 °C).
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roton-conductive solids have spurred tremendous interest among the scientific community owing to their application in diverse technologies including fuel cells, redox flow batteries, humidity sensors, and water electrolyzers.1−4 Nafion-based proton-conducting polymers are considered to be the benchmark in this context because of their high conductivity.5−7 However, their amorphous structures go against exploring the relationship between the structural characteristics and conducting mechanism. In addition, the high cost of these fluorinated polymeric electrolytes limits their large-scale usage as well.8 Thus, it is very desirable to develop new proton-conductive alternatives with good working performance. Bearing the merits of easy synthesis, modular nature, wellordered cavity, and crystalline architecture, metal−organic frameworks (MOFs) have emerged as a new type of proton conductor.9−15 While a huge effort has been invested to achieve high conductivity by accommodating proton carriers (e.g., phospate, sulfate, ammonium, histamine, imidazole) into MOFs,16−27 these guest proton agents could be easily released under hot-moist operating conditions, where their host chemical stability also remains a challenging issue because most MOFs are unstable in water. Being an exceptionally stable subclass of MOFs, zirconiumbased MOFs have attracted extensive attention in many fields, including water adsorption, catalysis, drug delivery, electrochemistry, and so on.28−37 Functionalization of zirconium-based MOFs with hydrophilic species could satisfy the dual challenges of proton conduction and chemical stability for use as solid-state electrolytes. As reported by Paesani and co-workers, grafting additional carboxyl moieties onto the ligands of UiO-66 greatly facilitated proton transport.9 On the same UiO-66 model, Hong and co-workers proposed a postsynthetic sulfonation plan to afford efficient proton conduction.19 Vivani and co-workers © XXXX American Chemical Society
Received: November 6, 2018
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DOI: 10.1021/acs.inorgchem.8b03132 Inorg. Chem. XXXX, XXX, XXX−XXX
Communication
Inorganic Chemistry
Figure 1. (a) Zirconium(4+) 1,2,3-trioxobenzene coordination rod, porphyrin linkers of (b) THPP and (c) THBPP, (d) nbo topological net, and (e) ZrPP-1 and (f) ZrPP-2 structures. Color code: C, gray; O, red; N, blue; Zr, dark-yellow or teal polyhedra. All H atoms are not depicted for clarity.
ZrPP-n were prepared according to the previous procedure44 in a N,N-dimethylformamide aqueous solution containing ZrCl4 and a porphyrin pyrogallic ligand, placed and sealed in a Teflonlined stainless-steel Parr autoclave, and heated at 140 °C in an oven for 24 h. The phase purity of the products was testified by a comparison of the experimental powder X-ray diffraction (PXRD) patterns with the refined ones obtained in the molecular modeling (Figures 2a and S1 and S2). The structures can be described as three-dimensional porous nbo-type structures resulting from the connection of one-dimensional Zr4+-oxo rodlike chains spaced by cruciform tetratopic porphyrins (Figure 1). As shown in Figures S3−S5, NMR and IR along with thermal gravimetric and elemental analyses, including inductively coupled plasma (ICP) spectroscopy, afford the existence of lattice dimethylamine, Me2NH, and water molecules in the pore, and statistically distributed H+ positions on phenol groups and Me2NH guests in a ratio of nearly 1:2. ZrPP-n, especially ZrPP-1, are rather chemically stable, which can resist contact with moisture or even a saturated NaOH solution (Figure S6). The porosity was initially examined by N2 adsorption− desorption isotherms at 77 K (Figures S7 and S8). Prior to testing, the as-synthesized samples were exchanged with MeOH for 3 days and then activated at 120 °C under a vacuum for 10 h. To further illustrate the water-trap capacity of the samples, the H2O adsorption−desorption isotherms were recorded on an Intrinsic DVS instrument from Surface Measurement Systems, Ltd., at relative humidities (RHs) ranging from 0 to 95% and room temperature (Figure 2b). The amount of adsorbed water increased with elevated RH, and the highest water content reached 15.2 molecules per formula (291 cm3 g−1) and 18.6 molecules per formula (282 cm3 g−1) at 95% RH for ZrPP-1 and ZrPP-2, respectively. The presence of high-density H+ carriers, such as acidic hydroxy groups on the pyrogallol linker enhanced by the Zr4+ coordination, guest Me2NH2+ cations, and lattice water molecules, points to the possible use of ZrPP-n as protonconducting materials. Impedance measurements were carried
Figure 2. (a) PXRD patterns of ZrPP-1 and ZrPP-2 as-synthesized and treated by immersion in water for 7 days. (b) Water-vapor adsorption− desorption isotherms of ZrPP-1 and ZrPP-2 at 298 K and under 1 atm.
out on a Solartron SI1260 analyzer, with a temperature- and humidity-controlled oven, to assess the proton conductivity of ZrPP-n with a quasi-four-probe method on a pelleted sample. The frequency ranged from 0.1 Hz to 10 MHz with an applied alternating-current (ac) voltage of 100 mV. Measurements were first collected from 50% to 98% RH and at 25 °C (Figure 3a,b). As evaluated from the low-frequency-end intercept of the arc on the real axis in the Nyquist plots, the resulting total conductivity σ values of ZrPP-1 and ZrPP-2 increased from 1.1 × 10−5 and 3.9 × 10−6 to 8.0 × 10−3 and 4.2 × 10−3 S cm−1, respectively, when the RH was varied from 50% to 98% (Figure S9), suggesting that their conductivity σ values heavily depend on the humidity. The observed proton conductivities are among the very highest values reported for MOFs, such as (NH4)2(adp)[Zn2(ox)3]· 3H2O (8.0 × 10−3 S cm−1; adp = adipic acid and ox = oxalate),45 CPM-103a/b (6.5 × 10−3/5.9 × 10−3 S cm−1),21 Ti/Fe-CAT-5 (8.2 × 10−4/5.0 × 10−2 S cm−1),42 BUT-8(Cr) (1.5 × 10−2 S cm−1),12 MIL-163 (2.3 × 10−4 S cm−1),40 and KAUST-7′ (6.7 × 10−3 S cm−1),46 all at >95% RH and 25 °C. Moreover, their remarkable performance is maintained for at least two successive times without an appreciable decrease in proton conduction (Figures S10 and S11). PXRD collected on ZrPP-n after ac impedance tests also confirmed that their structure integrity showed no obvious change (Figures S14 and S15). These findings further verified that ZrPP-n are chemically robust conductors. The dependence of the conductivity σ on the temperature was investigated at 95% RH between 25 and 65 °C to further probe the conducting mechanism (Figures S12 and S13). Calculated by Arrhenius plots, the activation energies (Ea) are 0.21 and 0.23 eV for ZrPP-1 and ZrPP-2, respectively B
DOI: 10.1021/acs.inorgchem.8b03132 Inorg. Chem. XXXX, XXX, XXX−XXX
Communication
Inorganic Chemistry
coupled with partial protonation of 1,2,3-trioxobenzene and the presence of extraframework Me2NH2+, making them well suited as ideal platforms for proton conduction. Pelleted samples of fresh ZrPP-1 and ZrPP-2 exhibit excellent proton-transport behavior (8.0 × 10−3 and 4.2 × 10−3 S cm−1, respectively, under 98% RH at 25 °C), which is presumably governed by the Grotthuss mechanism in view of the low energy barriers (Ea = 0.21 and 0.23 eV for ZrPP-1 and ZrPP-2, respectively). Further efforts to facilitate proton conduction by an azole-loading strategy and explore their other electrocatalytic activities are currently underway.
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.8b03132.
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Detailed experimental procedures and additional characterizing figures for ZrPP-n (n = 1 and 2) (PDF)
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. ORCID
Qipu Lin: 0000-0002-7723-3676 Author Contributions
All authors have given approval to the final version of the manuscript. Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This work was supported by the National Science Foundation of China (Grant 21501028), the National Science Foundation of Fujian Province (Grant 2017J01039), the Strategic Priority Research Program of Chinese Academy of Sciences (Grant XDB20000000), and the Hundred-Talent Program of Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences.
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Figure 3. Nyquist plots of pelleted samples of (a) ZrPP-1 and (b) ZrPP2 at different RHs and 25 °C. (c) Arrhenius plots of the proton conductivity of ZrPP-1 and ZrPP-2 at 95% RH.
REFERENCES
(1) Kreuer, K.-D.; Paddison, S. J.; Spohr, E.; Schuster, M. Transport in Proton Conductors for Fuel-Cell Applications: Simulations, Elementary Reactions, and Phenomenology. Chem. Rev. 2004, 104, 4637− 4678. (2) Zhong, H.; Fu, Z.; Taylor, J. M.; Xu, G.; Wang, R. Inorganic AcidImpregnated Covalent Organic Gels as High-Performance ProtonConductive Materials at Subzero Temperatures. Adv. Funct. Mater. 2017, 27, 1701465. (3) Miyake, J.; Taki, R.; Mochizuki, T.; Shimizu, R.; Akiyama, R.; Uchida, M.; Miyatake, K. Design of Flexible Polyphenylene ProtonConducting Membrane for Next-Generation Fuel Cells. Sci. Adv. Mater. 2017, 3, No. eaao0476. (4) Jiao, K.; Ni, M. Challenges and Opportunities in Modelling of Proton Exchange Membrane Fuel Cells (PEMFC). Int. J. Energy Res. 2017, 41, 1793−1797. (5) Zhang, H.; Shen, P. K. Recent Development of Polymer Electrolyte Membranes for Fuel Cells. Chem. Rev. 2012, 112, 2780− 2832. (6) McKeen, J. C.; Yan, S. Y.; Davis, M. E. Proton Conductivity in Sulfonic Acid-Functionalized Zeolite Beta: Effect of Hydroxyl Group. Chem. Mater. 2008, 20, 3791−3793.
(Figure 3c). The Ea values are lower than some well-known hydrated proton conductors, such as PCMOF-5 (0.32 eV),18 (NH4)2(adp)[Zn2(ox)3]·3H2O (0.63 eV),45 Ti-CAT-5 (0.43 eV),42 and CPM-103 (0.66 eV),21 but comparable to those of Fe-CAT-5 (0.24 eV),42 MIL-163 (0.25 eV),40 KAUST-7′ (0.19 eV),46 and Nafion (0.22 eV). The low activation energies indicate that proton transfer is governed by the Grotthuss mechanism. Extensive hydrogen bonding between acidic O−H (where the nearest opposite O···O distance along the Zr4+ oxo chain is 2.84 Å) and the surrounding Me2NH2+/H2O is believed here to provide efficient pathways for proton conduction triggered by humidity. In conclusion, two zirconium polyphenolate porphyrin MOFs, ZrPP-n (n = 1 and 2), featured infinite zirconium(4+) oxide coordination chains linked via porphyrin macrocycles and C
DOI: 10.1021/acs.inorgchem.8b03132 Inorg. Chem. XXXX, XXX, XXX−XXX
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Inorganic Chemistry (7) Luo, H. B.; Ren, L. T.; Ning, W. H.; Liu, S. X.; Liu, J. L.; Ren, X. M. Robust Crystalline Hybrid Solid with Multiple Channels Showing High Anhydrous Proton Conductivity and a Wide Performance Temperature Range. Adv. Mater. 2016, 28, 1663−1667. (8) Yang, F.; Huang, H.; Wang, X.; Li, F.; Gong, Y.; Zhong, C.; Li, J.-R. Proton Conductivities in Functionalized UiO-66: Tuned Properties, Thermogravimetry Mass, and Molecular Simulation Analyses. Cryst. Growth Des. 2015, 15, 5827−5833. (9) Borges, D. D.; Devautour-Vinot, S.; Jobic, H.; Ollivier, J.; Nouar, F.; Semino, R.; Devic, T.; Serre, C.; Paesani, F.; Maurin, G. Proton Transport in a Highly Conductive Porous Zirconium-Based MetalOrganic Framework: Molecular Insight. Angew. Chem., Int. Ed. 2016, 55, 3919−3924. (10) Ramaswamy, P.; Wong, N. E.; Shimizu, G. K. MOFs as Proton Conductors-Challenges and Opportunities. Chem. Soc. Rev. 2014, 43, 5913−5932. (11) Gao, W. Y.; Chrzanowski, M.; Ma, S. Metal-Metalloporphyrin Frameworks: a Resurging Class of Functional Materials. Chem. Soc. Rev. 2014, 43, 5841−5866. (12) Yang, F.; Xu, G.; Dou, Y.; Wang, B.; Zhang, H.; Wu, H.; Zhou, W.; Li, J.-R.; Chen, B. A Flexible Metal-Organic Framework with a High Density of Sulfonic Acid Sites for Proton Conduction. Nat. Energy 2017, 2, 877−883. (13) Yamada, T.; Nankawa, T. High Proton Conductivity of Zinc Oxalate Coordination Polymers Mediated by a Hydrogen Bond with Pyridinium. Inorg. Chem. 2016, 55, 8267−8270. (14) Liu, R.; Zhao, L.; Yu, S.; Liang, X.; Li, Z.; Li, G. Enhancing Proton Conductivity of a 3D Metal-Organic Framework by Attaching Guest NH3 Molecules. Inorg. Chem. 2018, 57, 11560−11568. (15) Yoon, M.; Suh, K.; Natarajan, S.; Kim, K. Proton Conduction in Metal-Organic Frameworks and Related Modularly Built Porous Solids. Angew. Chem., Int. Ed. 2013, 52, 2688−2700. (16) Shi, J.; Li, J.; Zeng, H.; Zou, G.; Zhang, Q.; Lin, Z. Water Stable Oxalate-based Coordination Polymers with in Situ Generated Cyclic Dipeptides Showing High Proton Conductivity. Dalton Trans 2018, 47, 15288−15292. (17) Wang, K.; Li, T.; Zeng, H.; Zou, G.; Zhang, Q.; Lin, Z. Ionothermal Synthesis of Open-Framework Metal Phosphates Using a Multifunctional Ionic Liquid. Inorg. Chem. 2018, 57, 8726−8729. (18) Sadakiyo, M.; Okawa, H.; Shigematsu, A.; Ohba, M.; Yamada, T.; Kitagawa, H. Promotion of Low-Humidity Proton Conduction by Controlling Hydrophilicity in Layered Metal-Organic. J. Am. Chem. Soc. 2012, 134, 5472−5475. (19) Phang, W. J.; Jo, H.; Lee, W. R.; Song, J. H.; Yoo, K.; Kim, B.; Hong, C. S. Superprotonic Conductivity of a UiO-66 Framework Functionalized with Sulfonic Acid Groups by Facile Postsynthetic Oxidation. Angew. Chem., Int. Ed. 2015, 54, 5142−5146. (20) Ramaswamy, P.; Wong, N. E.; Gelfand, B. S.; Shimizu, G. K. A Water Stable Magnesium MOF That Conducts Protons over 10−2 S cm−1. J. Am. Chem. Soc. 2015, 137, 7640−7643. (21) Zhai, Q. G.; Mao, C.; Zhao, X.; Lin, Q.; Bu, F.; Chen, X.; Bu, X.; Feng, P. Cooperative Crystallization of Heterometallic IndiumChromium Metal-Organic Polyhedra and Their Fast Proton Conductivity. Angew. Chem., Int. Ed. 2015, 54, 7886−7890. (22) Sadakiyo, M.; Yamada, T.; Kitagawa, H. Proton Conductivity Control by Ion Substitution in a Highly Proton-Conductive MetalOrganic Framework. J. Am. Chem. Soc. 2014, 136, 13166−13169. (23) Shigematsu, A.; Yamada, T.; Kitagawa, H. Wide Control of Proton Conductivity in Porous Coordination Polymers. J. Am. Chem. Soc. 2011, 133, 2034−2036. (24) Bureekaew, S.; Horike, S.; Higuchi, M.; Mizuno, M.; Kawamura, T.; Tanaka, D.; Yanai, N.; Kitagawa, S. One-Dimensional Imidazole Aggregate in Aluminium Porous Coordination Polymers with High Proton Conductivity. Nat. Mater. 2009, 8, 831−836. (25) Sadakiyo, M.; Kasai, H.; Kato, K.; Takata, M.; Yamauchi, M. Design and Synthesis of Hydroxide Ion-Conductive Metal-Organic Frameworks Based on Salt Inclusion. J. Am. Chem. Soc. 2014, 136, 1702−1705.
(26) Ye, Y.; Guo, W.; Wang, L.; Li, Z.; Song, Z.; Chen, J.; Zhang, Z.; Xiang, S.; Chen, B. Straightforward Loading of Imidazole Molecules into Metal-Organic Framework for High Proton Conduction. J. Am. Chem. Soc. 2017, 139, 15604−15607. (27) Nguyen, M. V.; Lo, T. H. N.; Luu, L. C.; Nguyen, H. T. T.; Tu, T. N. Enhancing Proton Conductivity in a Metal-Organic Framework at T > 80 °C by an Anchoring Strategy. J. Mater. Chem. A 2018, 6, 1816− 1821. (28) Kandiah, M.; Nilsen, M. H.; Usseglio, S.; Jakobsen, S.; Olsbye, U.; Tilset, M.; Larabi, C.; Quadrelli, E. A.; Bonino, F.; Lillerud, K. P. Synthesis and Stability of Tagged UiO-66 Zr-MOFs. Chem. Mater. 2010, 22, 6632−6640. (29) Feng, D.; Wang, K.; Su, J.; Liu, T. F.; Park, J.; Wei, Z.; Bosch, M.; Yakovenko, A.; Zou, X.; Zhou, H. C. A Highly Stable Zeotype Mesoporous Zirconium Metal-Organic Framework with Ultralarge Pores. Angew. Chem., Int. Ed. 2015, 54, 149−154. (30) Bai, Y.; Dou, Y.; Xie, L. H.; Rutledge, W.; Li, J. R.; Zhou, H. C. ZrBased Metal-Organic Frameworks: Design, Synthesis, Structure, and Applications. Chem. Soc. Rev. 2016, 45, 2327−2367. (31) Wang, B.; Lv, X. L.; Feng, D.; Xie, L. H.; Zhang, J.; Li, M.; Xie, Y.; Li, J. R.; Zhou, H. C. Highly Stable Zr(IV)-Based Metal-Organic Frameworks for the Detection and Removal of Antibiotics and Organic Explosives in Water. J. Am. Chem. Soc. 2016, 138, 6204−6216. (32) Feng, D.; Gu, Z. Y.; Li, J. R.; Jiang, H. L.; Wei, Z.; Zhou, H. C. Zirconium-Metalloporphyrin PCN-222: Mesoporous Metal-Organic Frameworks with Ultrahigh Stability as Biomimetic Catalysts. Angew. Chem., Int. Ed. 2012, 51, 10307−10310. (33) Zhang, H.; Wei, J.; Dong, J.; Liu, G.; Shi, L.; An, P.; Zhao, G.; Kong, J.; Wang, X.; Meng, X.; Zhang, J.; Ye, J. Efficient Visible-LightDriven Carbon Dioxide Reduction by a Single-Atom Implanted MetalOrganic Framework. Angew. Chem., Int. Ed. 2016, 55, 14310−14314. (34) Tan, L.-L.; Song, N.; Zhang, S. X.-A.; Li, H.; Wang, B.; Yang, Y.W. Ca2+, pH and Thermo Triple-Responsive Mechanized Zr-Based MOFs for on-Command Drug Release in Bone Diseases. J. Mater. Chem. B 2016, 4, 135−140. (35) Lin, Q.; Bu, X.; Kong, A.; Mao, C.; Zhao, X.; Bu, F.; Feng, P. New Heterometallic Zirconium Metalloporphyrin Frameworks and Their Heteroatom-Activated High-Surface-Area Carbon Derivatives. J. Am. Chem. Soc. 2015, 137, 2235−2238. (36) Feng, D.; Gu, Z. Y.; Chen, Y. P.; Park, J.; Wei, Z.; Sun, Y.; Bosch, M.; Yuan, S.; Zhou, H. C. A Highly Stable Porphyrinic Zirconium Metal-Organic Framework with shp-a Topology. J. Am. Chem. Soc. 2014, 136, 17714−17717. (37) Liu, T. F.; Feng, D.; Chen, Y. P.; Zou, L.; Bosch, M.; Yuan, S.; Wei, Z.; Fordham, S.; Wang, K.; Zhou, H. C. Topology-Guided Design and Syntheses of Highly Stable Mesoporous Porphyrinic Zirconium Metal-Organic Frameworks with High Surface Area. J. Am. Chem. Soc. 2015, 137, 413−419. (38) Donnadio, A.; Nocchetti, M.; Costantino, F.; Taddei, M.; Casciola, M.; da Silva Lisboa, F.; Vivani, R. A Layered Mixed Zirconium Phosphate/Phosphonate With Exposed Carboxylic and Phosphonic Groups: X-Ray Powder Structure and Proton Conductivity Properties. Inorg. Chem. 2014, 53, 13220−13226. (39) Zhang, J.; Chen, L.; Gui, D.; Zhang, H.; Zhang, D.; Liu, W.; Huang, G.; Diwu, J.; Chai, Z.; Wang, S. An Ingenious One-Dimensional Zirconium Phosphonate with Efficient Strontium Exchange Capability and Moderate Proton Conductivity. Dalton Trans 2018, 47, 5161− 5165. (40) Mileo, P. G. M.; Devautour-Vinot, S.; Mouchaham, G.; Faucher, F.; Guillou, N.; Vimont, A.; Serre, C.; Maurin, G. Proton-Conducting Phenolate-Based Zr Metal-Organic Framework: A Joint ExperimentalModeling Investigation. J. Phys. Chem. C 2016, 120, 24503−24510. (41) Darago, L. E.; Aubrey, M. L.; Yu, C. J.; Gonzalez, M. I.; Long, J. R. Electronic Conductivity, Ferrimagnetic Ordering, and Reductive Insertion Mediated by Organic Mixed-Valence in a Ferric Semiquinoid Metal-Organic Framework. J. Am. Chem. Soc. 2015, 137, 15703−15711. (42) Nguyen, N. T.; Furukawa, H.; Gandara, F.; Trickett, C. A.; Jeong, H. M.; Cordova, K. E.; Yaghi, O. M. Three-Dimensional MetalD
DOI: 10.1021/acs.inorgchem.8b03132 Inorg. Chem. XXXX, XXX, XXX−XXX
Communication
Inorganic Chemistry Catecholate Frameworks and Their Ultrahigh Proton Conductivity. J. Am. Chem. Soc. 2015, 137, 15394−15397. (43) Nagarkar, S. S.; Unni, S. M.; Sharma, A.; Kurungot, S.; Ghosh, S. K. Two-in-One: Inherent Anhydrous and Water-Assisted High Proton Conduction in a 3D Metal-Organic Framework. Angew. Chem., Int. Ed. 2014, 53, 2638−2642. (44) Chen, E.-X.; Qiu, M.; Zhang, Y.-F.; Zhu, Y.-S.; Liu, L.-Y.; Sun, Y.Y.; Bu, X.; Zhang, J.; Lin, Q. Acid and Base Resistant Zirconium Polyphenolate-Metalloporphyrin Scaffolds for Efficient CO2 Photoreduction. Adv. Mater. 2018, 30, 1704388. (45) Sadakiyo, M.; Yamada, T.; Kitagawa, H. Rational Designs for Highly Proton-Conductive Metal-Organic Frameworks. J. Am. Chem. Soc. 2009, 131, 9906−9907. (46) Mileo, P. G. M.; Adil, K.; Davis, L.; Cadiau, A.; Belmabkhout, Y.; Aggarwal, H.; Maurin, G.; Eddaoudi, M.; Devautour-Vinot, S. Achieving Superprotonic Conduction with a 2D Fluorinated MOF. J. Am. Chem. Soc. 2018, 140, 13156−13160.
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DOI: 10.1021/acs.inorgchem.8b03132 Inorg. Chem. XXXX, XXX, XXX−XXX
