Spectroscopically Resolved Binding Sites for the Adsorption of Sarin

Subscriber access provided by Nottingham Trent University

Surfaces, Interfaces, and Catalysis; Physical Properties of Nanomaterials and Materials

Spectroscopically Resolved Binding Sites for the Adsorption of Sarin Gas in a Metal-Organic Framework: Insights Beyond Lewis Acidity Jacob A. Harvey, Monica McEntee, Sergio J. Garibay, Erin M. Durke, Jared B. DeCoste, Jeffery A. Greathouse, and Dorina F Sava Gallis J. Phys. Chem. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.jpclett.9b01867 • Publication Date (Web): 12 Aug 2019 Downloaded from pubs.acs.org on August 13, 2019

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters

Spectroscopically Resolved Binding Sites for the Adsorption of Sarin Gas in a Metal-Organic Framework: Insights Beyond Lewis Acidity Jacob A. Harvey,†¥ Monica L. McEntee,‡¥ Sergio J. Garibay,‡ Erin M. Durke,‡ Jared B. DeCoste,‡ Jeffery A. Greathouse,† Dorina F. Sava Gallis§* †Geochemistry

Department, Sandia National Laboratories, Albuquerque, NM 87185, USA Capabilities Development Command Chemical Biological Center, U.S. Army Research, Development and Engineering Command, 8198 Blackhawk Road, Aberdeen Proving Ground, MD 21010, USA §Nanoscale Sciences Department, Sandia National Laboratories, Albuquerque, NM 87185, USA ‡Combat

ABSTRACT: Here we report molecular level details regarding the adsorption of sarin (GB) gas in a prototypical zirconiumbased metal-organic framework (MOF, UiO-66). By combining predictive modeling and experimental spectroscopic techniques we unambiguously identify several unique bindings sites within the MOF, using the P=O stretch frequency of GB as a probe. Remarkable agreement between predicted and experimental IR spectrum is demonstrated. As previously hypothesized, the undercoordinated Lewis acid metal site is the most favorable binding site. Yet multiple sites participate in the adsorption process; specifically, the Zr-chelated hydroxyl groups form hydrogen bonds with the GB molecule, and GB weakly interacts with fully coordinated metals. Importantly, this work highlights that subtle orientational effects of bound GB are observable via shifts in characteristic vibrational modes; this finding has large implications for degradation rates and opens a new route for future materials design.

TOC

Developing an, often elusive, molecular level picture for the chemistry occurring at solid catalytic interfaces, e.g., metal-organic frameworks (MOFs), is an essential component of rational materials design. Several studies have shown that manipulating structural details on the atomistic level can have drastic effects on these materials’ chemical and mechanical properties.1-3 Because of recent real-world events, a particularly important class of reactions to understand is the degradation of organophosphorus chemical warfare agents (CWAs), e.g., sarin (GB).4 Studying this system has a high degree of difficulty due to its high toxicity. Many commonly employed experimental capabilities cannot be readily utilized and therefore accurate molecular-level details about the GB-surface structure are lacking. The use of simulants with related chemical structures and functionality is widely

implemented, despite the fact that their reactivity and adsorption is not necessarily well correlated with that of the actual agent.5-8 Molecular modeling is therefore an invaluable predictive tool that can be used to address these shortcomings. Many studies have provided important details regarding the adsorption and degradation mechanism of CWAs at various interfaces.9-24 Although informative, these modeling efforts typically focus on (i) adsorption of CWAs at non-representative small clusters2122,25 or (ii) calculation of reaction barriers which only qualitatively compare with experimentally determined degradation rates.5,16 Therefore, a need remains to validate computational efforts that capture a wider array of favorable CWA-framework interactions in the quest to rationalize design principles for materials with superior adsorption properties.

ACS Paragon Plus Environment

The Journal of Physical Chemistry Letters 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Several studies have identified MOFs as a good chemical adsorbers of CWAs and related compounds, showing excellent catalytic activity.14,16-18,20 Computational work has identified the adsorption process to be rate limiting21-22 and therefore remains a critical first step in the degradation of these chemicals. Many authors, both experimentalists and theorists, propose undercoordinated Lewis acid metal sites, henceforth referred to as “defects”, as the likely binding sites for the adsorption and reactivity of organophosphorus compounds.16 A well-studied Zr-based MOF, and the focus of our work here, is UiO-66; which consists of Zr6O4(OH)4 metal clusters bridged by 12 ditopic 1,4-

benzenedicarboxylate (BDC) linkers (Figure 1).26 In this MOF, the structure of the defect consists of a removed organic ligand; leaving behind the desired undercoordinated metal atom and a neighboring ZrOH group. While it is hypothesized that binding and degradation occurs at this site, there is currently no direct observation of CWA adsorption, or related molecules, at a defect site.

Figure 1. 3D structure of UiO-66 (left) with an expanded view of a single metal cluster (O = red, H = white, C = gray, Zr = teal). Binding sites considered in this study (Zr defect, ZrOH, µ3-OH) are indicated; the fully coordinated (ideal) metal site is not indicated for visual clarity. Difference IR spectra (right) are utilized throughout this study to highlight changes to the spectra upon GB adsorption. These are constructed by subtracting the bare MOF IR spectrum from the GB-exposed MOF IR spectrum. Representative images of the raw MOF+GB and pure MOF spectra are depicted here to clarify the importance of utilizing the difference spectra

In this context, infrared (IR) spectroscopy is well suited to probe the molecular details for the adsorption of molecules on various surfaces. The P=O bond in GB (Figure 1), and other organophosphorus compounds, is a particularly good hydrogen bond acceptor, and IR spectroscopy can be used to probe this interaction with high sensitivity.15 Recent studies have used this approach to monitor the adsorption and potential degradation of organophosphorus compounds on a variety of surfaces including silica,13,15 anatase,27 polycrystalline cupric oxide,28 zinc oxide,29 and MOFs.30-32 MOF based studies, which are limited to dimethyl methylphophonate (DMMP, a popular GB simulant), have all observed a ~100 cm-1 red shift and significant broadening in the P=O bond stretch frequency.

Yet an atomistic interpretation of this observation is challenging without a corresponding computational component. In this study we seek to address this knowledge gap by using density functional theory (DFT) calculated and high vacuum in situ IR spectroscopy to probe the GB adsorption surface in UiO-66. The approach involves predicting the frequency of characteristic vibrational modes in GB while bound at various hypothesized adsorption sites and comparing directly to associated experimental spectra. Excellent agreement is observed with comparison to experimental IR spectra, thereby providing experimental evidence of GB bound to distinct sites on UiO66. More broadly, gathering the molecular level understanding of the adsorption and degradation process


Page 2 of 7

Page 3 of 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters aids with the rational design of materials with predetermined features. The three-dimensional structure of defective UiO-66 is given in Figure 1 with a zoomed in perspective of the binding sites probed within this study. All experimental IR spectra presented here were collected in situ using a vacuum chamber with a base pressure of ~3x10-9 Torr.33 A UiO-66 sample containing ~9% defects was used for all experiments. Caution! Experiments using GB should be run by trained personnel using appropriate safety procedures only. Simulated IR spectra were calculated by diagonalizing the Hessian matrix calculated using the density functional

perturbation theory (DFPT) method34-37 within the Vienna Ab Initio Simulation Package (VASP).38-41 See Supporting Information for full experimental and computational details. Spectra are presented as difference spectra in which the unloaded MOF spectra is substracted from the GB-loaded MOF spectra. Representatitve raw spectra are shown in Figure 1. In this type of spectrum, positive peaks represent new species or frequency shifts in MOF modes, while negative peaks represent degradation or frequency shifts of MOF modes. Excellent agreement between the experimental and simulated gas phase GB spectra was observed (Figure S4) thereby testing the appropriateness of the computational approach used here.

Figure 2. Comparison of the experimental and simulated IR spectra for GB bound on UiO-66 in the low wavenumber region. a. Experimental spectra of the sample exposed to the high GB pressure (solid), low GB pressure (dashed), and prior to (top) and after (bottom) evacuation of GB b. Direct comparison of prior to evacuation experimental spectra (black) to simulated spectra calculated when GB is bound at a defect site (blue), the ZrOH site (red), and an ideal site (green). Characteristic GB modes for the P=O, C-O, and P-F stretches are indicated. c-e. Snapshots of the optimized geometry for the bound states at the defect site, ZrOH site, and ideal site with bond distances between the Lewis acid site and the P=O group shown.

Experimental IR spectra of GB in UiO-66 are shown in Figure 2a-b. Shown are spectra taken before (top) and after (bottom) evacuating from high (solid-line, 8x10-5 Torr) and low (dashed-line, 5x10-6 Torr) GB pressure states (see Figures S5 and S6 for raw and difference spectra at additional pressures). Species that remain after evacuating are considered to be chemisorbed to the UiO-66 framework. A distinct red shift from the gas phase P=O stretch at 1300 cm-1 (experimental) and 1277 cm-1 (simulated) is observed when GB is adsorbed onto the MOF. New peaks in the “before evacuation” spectrum appear at 1266, 1235, and 1212 cm-1. The 1212 cm-1 peak is present in both “after evacuation” spectra, while the 1235 cm-1 and 1266 cm-1 peaks only appear in the high loading “after evacuation” spectrum. Our simulated spectra with GB bound at known sites are compared to the “before evacuation” spectrum for the high GB loading (Figure 2b). Experimental, “before

evacuation”, P=O frequencies seen at 1212, 1236, and 1266 cm-1 closely match the simulated P=O stretch frequencies for GB bound at the defect (1201 cm-1), missing linkercreated ZrOH (1232 cm-1), and ideal (1246 cm-1) sites, respectively. Therefore, we attribute these frequencies to GB bound at these specific sites. Optimized geometries for these sites are shown in Figure 2c-e. This mode is notably red shifted from the gas phase GB P=O frequency; an effect typically observed in hydrogen bonding environments.15,42 The magnitude of the red shifts observed here is consistent with previous studies of DMMP on MOFs.30-32 The 1212 cm-1 peak is observed in all experimental spectra, including the “after evacuation” spectra. This confirms that the defect site is the strongest, most favorable, binding site. Undercoordinated metal sites have been suggested as the active site for decomposition numerous times.16,19,21-23,32,43 However, until now, it has not been



unequivocally confirmed that GB does, in fact, bind at this defect site. While this is the most red-shifted peak it is also the least intense, however the sample contains few defects and therefore we expect less GB molecules bound at this site. The 1235 cm-1 and 1266 cm-1 peaks are only observed in the evacuated high GB loading spectrum, and the “before evacuation” spectra, indicating that the ZrOH and ideal binding sites follow the defect site in binding strength. This agrees quite well with previously reported binding energies: defect (18.0 kcal ⋅ mol-1) > ZrOH (7.25 kcal ⋅ mol-1) > ideal (-6.31 kcal ⋅ mol-1); where negative energies indicate non-favorable binding.25

Figure 3. Comparisons of the experimental and simulated IR spectra for GB bound on UiO-66 in the high wavenumber region. a. Experimental spectra of the sample evacuated from the high GB pressure (solid), low GB pressure (dashed), and prior to (top) and after (bottom) evacuation. b. Direct comparison of prior to evacuation experimental spectra (black) to simulated spectra calculated when GB is bound at the ZrOH site. Characteristic GB C-H and MOF ZrO-H modes are indicated.

By comparing computationally predicted shifts in the P=O stretch (with GB bound at specific sites) to experimental results, we showed that the ZrOH group plays a role in the adsorption process. To further investigate the role of the ZrOH group we examined the OH/CH stretching region of the spectrum (Figure 3a). A prominent peak in the high GB loading “before evacuation” experimental spectrum is observed at 3350 cm-1 with a nearly identical match in the simulated spectrum of GB bound at the ZrOH group at 3375 cm-1 (Figure 3b), which is due to the ZrO-H stretch. This mode is heavily red shifted from the computationally determined 3763 cm-1 frequency for the unbound ZrO-H stretch, which is confirmed by the slight negative peak at this frequency. In addition to red shifting O-H stretch frequencies, hydrogen bonding also leads to an increase in adsorption intensity; explaining the intensity difference between the negative and positive O-H stretch peaks.44 These results show that GB adsorbs, via hydrogen bonding, at a ZrOH site within UiO-66, and that this group plays a prominent role in the adsorption process. Our work here shows clear and compelling evidence that multiple binding sites exist within UiO-66 and that IR spectroscopy is very useful in distinguishing between these sites. This is consistent, albeit with more detail, with previous work by Plonka et al.32 which suggested that multiple binding sites might exist for DMMP in UiO-66. Our incorporation of a computational approach here allowed us to characterize those sites at the molecular level; namely being the defect, ZrOH, and ideal sites. Additionally, our computational work indicates that multiple P=O stretch frequencies are due to intact GB molecules at various binding sites. More specifically, the appearance of P-F stretches observed at 842, 852, and 866 cm-1 (experimental) and 812, 827, and 829 cm-1 (simulated) show that indeed no decomposition has occurred. In addition to changes in the MOF modes that occur upon adsorption of GB, we observe multiple peaks in the experimental “before evacuation”, Figure 3a, C-H stretch region. In an effort to probe the origin of these peaks we now consider multiple orientations of the GB molecule when bound at a defect site. The experimental peaks at 2988 and 2934 cm-1 closely match the GB vapor peaks (Figure S4). However new peaks at 2865 and 2860 cm-1 appear. Three orientations, which follow the nomenclature introduced by Troya5 were explored. Briefly, orientations are identified by the group that is colinear with the neighboring ZrOH group. The orientations of the defect bound GB molecule are shown in Figure 4. In this perspective the functional group to the left of the phosphorus atom indicates the named orientation. The simulated spectra for GB bound at defect sites (Figure 4) indicates that a new peak in this region appears and the location of this peak depends on the orientation of the molecule. In each of these orientations, GB C-H stretches appear at 3059 and 2968 cm-1, attributed to the symmetric and anti-symmetric stretches, however additional peaks appear at 2889, 2869, and 2812 cm-1 for the F, C, and O(sp3) orientations. The origin of this peak is a CH group interacting with the oxygen of the neighboring ZrOH (Figure 4 insets). This new GB⋯MOF interaction suggests that these additional peaks in the experimental spectra are


Page 4 of 7

Page 5 of 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters orientationally dependent. In the work presented here it seems that the F and C orientations are the most plausible as the C-H peak for the O(sp3) orientation is more highly red shifted than what is observed experimentally. Additionally, we note that the red shift in the CH stretch reverse mirrors the order of calculated binding energies; 18.8 kcal ⋅ mol-1, 18.0 kcal ⋅ mol-1, 16.2 kcal ⋅ mol-1 for the F, C, and O(sp3) approaches.25 This further supports the hypothesis that the O(sp3) orientation is not likely observed as it is the least energetically favorable. The orientation of the GB molecule has large implications for the reaction pathway19, increasing the degradation transition state barrier by upwards of 19 kcal ⋅ mol-1, and therefore understanding the preferred orientation is paramount and not well appreciated in the current literature.

Figure 4. Simulated spectra for three orientations of GB when bound at the defect site; F orientation (black), C orientation (blue) and O(sp3) orientation (red). A unique C-H stretch frequency is observed which is orientation dependent. The green box highlights the range of this frequency and is included to help guide the eye. This frequency is a result of an interaction between the CH group and the oxygen of the neighboring ZrOH group which is indicated in the associated snapshots. Snapshots of the optimized geometry for each orientation are shown along with their respective P=O⋯Zr and C-H⋯ZrOH distances. In this perspective, the functional group to the left of the P atom (purple) defines its orientation.

We note that an additional binding site for GB was explored computationally, which is the µ3-OH, and the results of which are relevant to the CH region of the specta. The simulated spectrum for when GB is bound at this site is

shown in Figure S7. The P=O stretch for the µ3-OH bound GB appears near the P=O stretch for the defect bound GB; 1211 and 1201 cm-1 respectively. This indicates that the fingerprint region might not be able to distinguish between



these two sites. It should be noted that a noticeable Zr-µ3OH bend appears at 1046 cm-1, although this is difficult to pinpoint in the experimental spectrum. While the P=O stretch for GB bound at the µ3-OH site was indistinguishable from the defect site, we observe distinct differences in the CH/OH stretch region. A strong peak at 3082 cm-1 appears, which is due to the µ3O-H stretch. This peak is difficult to isolate experimentally however the experimental peak at 3350 cm-1 (ZrO-H stretch) is quite broad and clearly not Gaussian in shape. We postulate that this peak along with the C-H stretches, are masking the appearance of the µ3O-H stretch. Deuteration of GB would potentially isolate this peak by mass shifting the GB C-H stretches and in fact, simulated spectra for deuterated GB at the µ3-OH site shifts the GB C-H stretches to 2100-2200 cm-1 (Figure S8). Here we demonstrated that DFT-calculated IR spectroscopy is an invaluable tool to probe and distinguish amongst adsorbate-adsorbent interactions; in this, case GB binding sites in UiO-66. Excellent agreement was observed between the simulated spectra for GB bound and high vacuum in situ experimental IR spectra; providing previously absent validation for computational efforts in this field. Our results show direct experimental evidence that undercoordinated Lewis acid metals are the preferred sites for GB adsorption in these materials. Three additional binding sites were confirmed; namely, ZrOH, fully coordinated metal, and µ3-OH. Moreover, specific orientations of defect bound GB were observed; this discovery is of utmost importance, as the orientation of the molecule can increase the magnitude of the largest degradation transition state barrier by 19 kcal ⋅ mol-1.19 This work therefore establishes a new path for materials design that focuses not just on the preferred binding sites, but the preferred orientation as well. The approach outlined in this study focuses on a well-characterized model surface (UiO66), however it is highly versatile and can be easily extended to other CWAs of interest, and to a wider range of materials and applications. Ongoing work is focused on modeling solvent effects on the degradation process at under coordinated metal sites.

ASSOCIATED CONTENT Supporting Information The Supporting Information is available free of charge on the ACS Publications website. Material synthesis and characterization, simulated and experimental GB vapor IR spectra, raw and difference experimental spectra for additional GB loadings, simulated IR spectrum for deuterated and protonated GB bound at a µ3-OH, and all input files needed for the calculations are given.

AUTHOR INFORMATION Corresponding Author *[email protected]

Author Contributions ¥These

authors contributed equally and should be consider cofirst authors.

ACKNOWLEDGMENT

We would like to thank Bryan Schindler and Eric Bruni for assisting in chemical warfare agent handling experiments. Additionally, the authors thank Darren Driscoll and John Morris for the design and development of the vacuum system. This work is supported by the Laboratory Directed Research and Development Program at Sandia National Laboratories. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in this article do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

REFERENCES (1) Furukawa, H.; Cordova, K. E.; O'Keeffe, M.; Yaghi, O. M. The Chemistry and Applications of Metal-Organic Frameworks. Science 2013, 341, 1230444. (2) Nishida, J.; Tamimi, A.; Fei, H.; Pullen, S.; Ott, S.; Cohen, S. M.; Fayer, M. D. Structural Dynamics Inside a Functionalized MetalOrganic Framework Probed by Ultrafast 2D IR Spectroscopy. Proc. Natl. Acad. Sci. U. S. A. 2014, 111, 18442-7. (3) Trickett, C. A.; Osborn Popp, T. M.; Su, J.; Yan, C.; Weisberg, J.; Huq, A.; Urban, P.; Jiang, J.; Kalmutzki, M. J.; Liu, Q., et al. Identification of the Strong Brønsted Acid Site in a MetalOrganic Framework Solid Acid Catalyst. Nat. Chem. 2019, 11, 170176. (4) Enserink, M. Chemical Weapons. U.N. Taps Special Labs to Investigate Syrian Attack. Science 2013, 341, 1050-1051. (5) Sava Gallis, D. F.; Harvey, J. A.; Pearce, C. J.; Hall, M. G.; DeCoste, J. B.; Kinnan, M. K.; Greathouse, J. A. Efficient MOF-Based Degradation of Organophosphorus Compounds in Non-Aqueous Environments. J. Mater. Chem. A 2018, 6, 3038-3045. (6) Matito-Martos, I.; Moghadam, P. Z.; Li, A.; Colombo, V.; Navarro, J. A. R.; Calero, S.; Fairen-Jimenez, D. Discovery of an Optimal Porous Crystalline Material for the Capture of Chemical Warfare Agents. Chem. Mater. 2018, 30, 4571-4579. (7) Agrawal, M.; Sava Gallis, D. F.; Greathouse, J. A.; Sholl, D. S. How Useful Are Common Simulants of Chemical Warfare Agents at Predicting Adsorption Behavior? J. Phys. Chem. C 2018, 122, 26061-26069. (8) Ploskonka, A. M.; DeCoste, J. B. Insight Into Organophosphate Chemical Warfare Agent Simulant Hydrolysis in Metal-Organic Frameworks. J. Hazard. Mater. 2019, 375, 191-197. (9) Bermudez, V. M. Computational Study of the Adsorption of Trichlorophosphate, Dimethyl Methylphosphonate, and Sarin on Amorphous SiO2. J. Phys. Chem. C 2007, 111, 9314-9323. (10) Bermudez, V. M. Quantum-Chemical Study of the Adsorption of DMMP and Sarin on γ-Al2O3. J. Phys. Chem. C 2007, 111, 3719-3728. (11) Bermudez, V. M. Computational Study of Environmental Effects in the Adsorption of DMMP, Sarin, and VX on γ-Al2O3: Photolysis and Surface Hydroxylation. J. Phys. Chem. C 2009, 113, 1917-1930. (12) Wilmsmeyer, A. R.; Uzarski, J.; Barrie, P. J.; Morris, J. R. Interactions and Binding Energies of Dimethyl Methylphosphonate and Dimethyl Chlorophosphate with Amorphous Silica. Langmuir 2012, 28, 10962-10967. (13) Wilmsmeyer, A. R.; Gordon, W. O.; Davis, E. D.; Troya, D.; Mantooth, B. A.; Lalain, T. A.; Morris, J. R. Infrared Spectra and Binding Energies of Chemical Warfare Nerve Agent Simulants on the Surface of Amorphous Silica. J. Phys. Chem. C 2013, 117, 1568515697. (14) Katz, M. J.; Mondloch, J. E.; Totten, R. K.; Park, J. K.; Nguyen, S. T.; Farha, O. K.; Hupp, J. T. Simple and Compelling Biomimetic Metal-Organic Framework Catalyst for the


Page 6 of 7

Page 7 of 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry Letters Degradation of Nerve Agent Simulants. Angew. Chem. Int. Ed. 2014, 53, 497-501. (15) Davis, E. D.; Gordon, W. O.; Wilmsmeyer, A. R.; Troya, D.; Morris, J. R. Chemical Warfare Agent Surface Adsorption: Hydrogen Bonding of Sarin and Soman to Amorphous Silica. J. Phys. Chem. Lett. 2014, 5, 1393-9. (16) Mondloch, J. E.; Katz, M. J.; Isley, W. C., 3rd; Ghosh, P.; Liao, P.; Bury, W.; Wagner, G. W.; Hall, M. G.; DeCoste, J. B.; Peterson, G. W., et al. Destruction of Chemical Warfare Agents Using MetalOrganic Frameworks. Nat. Mater. 2015, 14, 512-516. (17) Katz, M. J.; Moon, S. Y.; Mondloch, J. E.; Beyzavi, M. H.; Stephenson, C. J.; Hupp, J. T.; Farha, O. K. Exploiting Parameter Space in MOFs: A 20-Fold Enhancement of Phosphate-Ester Hydrolysis with UiO-66-NH2. Chem. Sci. 2015, 6, 2286-2291. (18) Katz, M. J.; Klet, R. C.; Moon, S.-Y.; Mondloch, J. E.; Hupp, J. T.; Farha, O. K. One Step Backward Is Two Steps Forward: Enhancing the Hydrolysis Rate of UiO-66 by Decreasing [OH–]. ACS Catal. 2015, 5, 4637-4642. (19) Troya, D. Reaction Mechanism of Nerve-Agent Decomposition with Zr-Based Metal Organic Frameworks. J. Phys. Chem. C 2016, 120, 29312-29323. (20) Bobbitt, N. S.; Mendonca, M. L.; Howarth, A. J.; Islamoglu, T.; Hupp, J. T.; Farha, O. K.; Snurr, R. Q. Metal-Organic Frameworks for the Removal of Toxic Industrial Chemicals and Chemical Warfare Agents. Chem. Soc. Rev. 2017, 46, 3357-3385. (21) Momeni, M. R.; Cramer, C. J. Dual Role of Water in Heterogeneous Catalytic Hydrolysis of Sarin by Zirconium-Based Metal-Organic Frameworks. ACS Appl. Mater. Interfaces 2018, 10, 18435-18439. (22) Momeni, M. R.; Cramer, C. J. Structural Characterization of Pristine and Defective [Zr12(μ3-O)8(μ3-OH)8(μ2-OH)6]18+ DoubleNode Metal–Organic Framework and Predicted Applications for Single-Site Catalytic Hydrolysis of Sarin. Chem. Mater. 2018, 30, 4432-4439. (23) Chen, H.; Liao, P.; Mendonca, M. L.; Snurr, R. Q. Insights into Catalytic Hydrolysis of Organophosphate Warfare Agents by Metal–Organic Framework NU-1000. J. Phys. Chem. C 2018, 122, 12362-12368. (24) Le, N. Q.; Ekuma, C. E.; Dunlap, B. I.; Gunlycke, D. FirstPrinciples Calculations of Sarin Adsorption on Anatase Surfaces. J. Phys. Chem. C 2018, 122, 2832-2839. (25) Harvey, J. A.; Greathouse, J. A.; Gallis, D. F. S. Defect and Linker Effects on the Binding of Organophosphorous Compounds in UiO-66 and Rare-Earth MOFs. J. Phys. Chem. C 2018, 122, 2688926896. (26) Cavka, J. H.; Jakobsen, S.; Olsbye, U.; Guillou, N.; Lamberti, C.; Bordiga, S.; Lillerud, K. P. A New Zirconium Inorganic Building Brick Forming Metal Organic Frameworks with Exceptional Stability. J. Am. Chem. Soc. 2008, 130, 13850-13851. (27) Hirakawa, T.; Sato, K.; Komano, A.; Kishi, S.; Nishimoto, C. K.; Mera, N.; Kugishima, M.; Sano, T.; Ichinose, H.; Negishi, N., et al. Experimental Study on Adsorption and Photocatalytic Decomposition of Isopropyl Methylphosphonofluoridate at Surface of TiO2 Photocatalyst. J. Phys. Chem. C 2010, 114, 23052314. (28) Trotochaud, L.; Tsyshevsky, R.; Holdren, S.; Fears, K.; Head, A. R.; Yu, Y.; Karslioglu, O.; Pletincx, S.; Eichhorn, B.; Owrutsky, J., et al. Spectroscopic and Computational Investigation of Room-Temperature Decomposition of a Chemical Warfare Agent Simulant on Polycrystalline Cupric Oxide. Chem. Mater. 2017, 29, 7483-7496.

(29) Holdren, S.; Tsyshevsky, R.; Fears, K.; Owrutsky, J.; Wu, T.; Wang, X.; Eichhorn, B. W.; Kuklja, M. M.; Zachariah, M. R. Adsorption and Destruction of the G-Series Nerve Agent Simulant Dimethyl Methylphosphonate on Zinc Oxide. ACS Catal. 2018, 9, 902-911. (30) Stassen, I.; Bueken, B.; Reinsch, H.; Oudenhoven, J. F. M.; Wouters, D.; Hajek, J.; Van Speybroeck, V.; Stock, N.; Vereecken, P. M.; Van Schaijk, R., et al. Towards Metal-Organic Framework Based Field Effect Chemical Sensors: UiO-66-NH2 for Nerve Agent Detection. Chem. Sci. 2016, 7, 5827-5832. (31) Wang, G.; Sharp, C.; Plonka, A. M.; Wang, Q.; Frenkel, A. I.; Guo, W.; Hill, C.; Smith, C.; Kollar, J.; Troya, D., et al. Mechanism and Kinetics for Reaction of the Chemical Warfare Agent Simulant, DMMP(g), with Zirconium(IV) MOFs: An Ultrahigh-Vacuum and DFT Study. J. Phys. Chem. C 2017, 121, 11261-11272. (32) Plonka, A. M.; Wang, Q.; Gordon, W. O.; Balboa, A.; Troya, D.; Guo, W.; Sharp, C. H.; Senanayake, S. D.; Morris, J. R.; Hill, C. L., et al. In Situ Probes of Capture and Decomposition of Chemical Warfare Agent Simulants by Zr-Based Metal Organic Frameworks. J. Am. Chem. Soc. 2017, 139, 599-602. (33) Basu, P.; Ballinger, T. H.; Yates, J. T. Wide Temperature Range IR Spectroscopy Cell for Studies of Adsorption and Desorption on High Area Solids. Rev. Sci. Instrum. 1988, 59, 13211327. (34) Giannozzi, P.; de Gironcoli, S.; Pavone, P.; Baroni, S. Ab Initio Calculation of Phonon Dispersions in Semiconductors. Phys. Rev. B 1991, 43, 7231-7242. (35) Giannozzi, P.; Baroni, S. Vibrational and Dielectric Properties of C60 From Density‐Functional Perturbation Theory. J. Chem. Phys. 1994, 100, 8537-8539. (36) Baroni, S.; de Gironcoli, S.; Dal Corso, A.; Giannozzi, P. Phonons and Related Crystal Properties From Density-Functional Perturbation Theory. Rev. Mod. Phys. 2001, 73, 515-562. (37) Karhanek, D.; Bucko, T.; Hafner, J. A Density-Functional Study of the Adsorption of Methane-Thiol on the (111) Surfaces of the Ni-Group Metals: II. Vibrational Spectroscopy. J. Phys. Condens. Matter. 2010, 22, 265006. (38) Kresse, G.; Hafner, J. Ab Initio Molecular Dynamics for Liquid Metals. Phys. Rev. B 1993, 47, 558-561. (39) Kresse, G.; Hafner, J. Ab Initio Molecular-Dynamics Simulation of the Liquid-Metal–Amorphous-Semiconductor Transition in Germanium. Phys. Rev. B 1994, 49, 14251-14269. (40) Kresse, G.; Furthmuller, J. Efficiency of Ab-Initio Total Energy Calculations for Metals and Semiconductors Using a PlaneWave Basis Set. Comp. Mater. Sci. 1996, 6, 15-50. (41) Kresse, G.; Furthmuller, J. Efficient Iterative Schemes for Ab Initio Total-Energy Calculations Using a Plane-Wave Basis Set. Phys. Rev. B 1996, 54, 11169-11186. (42) Sambrook, M. R.; Gass, I. A.; Cragg, P. J. Spectroscopic and Inclusion Properties of G-Series Chemical Warfare Agents and their Simulants: A DFT Study. Supramol. Chem. 2017, 30, 206-217. (43) Islamoglu, T.; Ortuno, M. A.; Proussaloglou, E.; Howarth, A. J.; Vermeulen, N. A.; Atilgan, A.; Asiri, A. M.; Cramer, C. J.; Farha, O. K. Presence versus Proximity: The Role of Pendant Amines in the Catalytic Hydrolysis of a Nerve Agent Simulant. Angew. Chem. Int. Ed. 2018, 57, 1949-1953. (44) Athokpam, B.; Ramesh, S. G.; McKenzie, R. H. Effect of Hydrogen Bonding on the Infrared Absorption Intensity of OH Stretch Vibrations. Chem. Phys. 2017, 488-489, 43-54.


Spectroscopically Resolved Binding Sites for the Adsorption of Sarin

Recommend Documents