Supporting Information. Cerium(IV) vs. Zirconium(IV) Based Metal-Organic Frameworks for Detoxification

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1 Supporting Information Cerium(IV) vs. Zirconium(IV) Based Metal-Organic Frameworks for Detoxification of a Nerve Agent Timur Islamoglu, Ahmet Atilgan, Su-Young Moon, Gregory W. Peterson, Jared B. DeCoste, Morgan Hall, Joseph T. Hupp and Omar K. Farha *,, Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States Edgewood Chemical Biological Center, U.S. Army Research, Development, and Engineering Command, 5183 Blackhawk Road, Aberdeen Proving Ground, Maryland 21010, United States Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia. Experimental Section Materials All reagents were purchased from commercial sources and used without further purification. Titanium(IV) chloride (99.9%), Dimethylechlorophosphate (96%), 4-nitrophenol (99%), tetrahydrofuran (99.9%, anhydrous, stabilized, acroseal) and triethylamine (99.7%, extra pure) were purchased from Fisher Scientific. Cerium(IV) ammonium nitrate (99.5% ) was purchased from Alfa Aesar. Caution! Experiments utilizing GD (soman) should be run by trained personnel using appropriate safety procedures. Instrumentation NMR spectra for hydrolysis profiles of simulant were collected on 400 MHz Agilent DD MR-400 at IMSERC (Integrated Molecular Structure Education and Research Center) of Northwestern University and NMR spectra for hydrolysis profiles of real nerve agent were collected on Varian INOVA 400 NMR spectrometer. Nitrogen isotherm measurements were carried out on a Micromeritics Tristar II 3020 at 77 K. Samples were activated at 100 C under vacuum for 12 h on Micromeritics Smart VacPrep instrument. Diffuse reflectance infrared spectra (DRIFTS) were recorded on a Nicolet 6700 FTIR spectrometer equipped with an MCT detector. The detector was cooled with liquid N2 and the spectra were collected under Ar atmosphere. KBr was utilized as a background spectrum. Scanning electron micrographs (SEM) images were taken using a Hitachi SU8030 at the EPIC facility (NUANCE Center-Northwestern University). Potentiometric titrations were completed with a Metrohm Titrando 905 equipped with Dosino ml and 10 ml dosing units as previously described. Calibration was performed with commercial ph buffers 2.00, 4.00, 7.00, and 9.00 (Metrohm). 1

2 Synthesis of dimethyl(4-nitrophenyl)phosphate (DMNP) 4-nitrophenol (3.40 g, 24.4 mmol) was added to a solution of TiCl4 (49 μl, 0.44 mmol) in 80 ml anhydrous THF in a 250 ml Schlenk flask. A solution of dimethylchlorophosphate (3.20 g, 22.2 mmol) in 20 ml anhydrous THF was added using a gas tight syringe followed by addition of anhydrous triethylamine (6.3 ml, 45.3 mmol). The resulting mixture was allowed to stir for 2 h at room temperature under nitrogen atmosphere. The resulting yellow reaction mixture was quenched with water and extracted with EtOAc (three times). Combined organic layers were dried over MgSO4 and then filtered and evaporated under vacuum. The resulting yellow oily crude product was purified using silicagel (Hexane:EtOAc) (1:1). The product was obtained as a light yellow oil (2.0 g, 37% yield). Caution: The product is highly toxic. Figure S1. 1 H NMR (500 MHz, CDCl3) spectrum of dimethyl(4-nitrophenyl)phosphate. Figure S2. 31 P NMR (400 MHz, CDCl3) spectrum of dimethyl(4-nitrophenyl)phosphate. 2

3 Synthesis of was synthesized according to a published procedure 1 with slight modifications. We found that soaking in a low boiling point solvent (acetone or ethanol) overnight was necessary for the sample to pass an outgas test under vacuum before running surface area measurements on scaled-up batches. In a 2 dram vial, 70.8 mg of BDC was dissolved in 2.5 ml DMF and then 800 μl of Ce(NH4)2(NO2)6 in water (0.533 M) was added to the mixture and stirred for 30 min at 100 o C on an aluminum heating block. The solid formed after 30 min was collected by centrifugation and washed with DMF three times (the sample sat in the fresh DMF for 1 h during each wash). The material was then washed with ethanol three times and soaked in ethanol overnight. The solid,, was isolated and dried under vacuum at 70 o C for 1 h and then at 100 o C at 16 h. Hydrolysis experiments In buffer: In a 1.5 dram vial, 1 ml of 10 % D2O solution (0.9 ml DI water/0.1ml D2O) buffered at ph 10 using 0.45 M N-ethylmorpholine was added followed by (3 mg, 1.5 µmol Ce6). The solution was sonicated for 15 sec and DMNP (4 μl, 25 μmol, ca. 6.2 mg) was added. The mixture was vigorously shaken for 15 sec before being transferred to an NMR tube. In situ 31 P NMR spectra of the mixture were collected every minute for 60 minutes and conversion was tracked by integrating the peaks associated with DMNP versus the dimethyl phosphate product obtained from cleavage of the P O bond. In water: In a 1.5 dram vial, 1 ml of 10 % D2O solution (0.9 ml DI water/0.1ml D2O), polyethylenimine (PEI) and (3 mg, 1.5 µmol Ce6) was added. The solution was sonicated for 15 sec and DMNP (4 μl, 25 μmol, ca. 6.2 mg) was added. The mixture was vigorously shaken for 15 sec before being transferred to an NMR tube. In situ 31 P NMR spectra of the mixture were collected every minute for 60 minutes and conversion was tracked by integrating the peaks associated with DMNP versus the dimethyl phosphate product obtained from cleavage of the P O bond. GD degradation: (3 mg) catalyst was loaded into a 5 mm NMR tube followed by the addition of 50 µl N-ethylmorpholine and 0.7 ml water (0.5 M N-ethylmorpholine, ph 10). GD (4.4 µl, 25 μmol) was then added, the tube capped, and vigorously shaken before placing into the NMR magnet for monitoring by 31 P NMR spectroscopy (Varian INOVA 400 NMR spectrometer; spectra referenced to external 85 % H3PO4) (A) 0.18 (B) Nitrogen Uptake (cm 3 /g) Zr-BDC (UIO-66) Incremental Pore Volume (cm 3 /g) Zr-BDC (UIO-66) Pressure (P/P 0 ) Pore Width (Angestrom) Figure S3. (A) N2 adsorption (closed symbol) and desorption (open symbol) isotherms at 77 K and (B) pore size distribution plots for UiO-66 and. 3

4 UiO Theta (degrees) Figure S4. PXRD patterns of (top) and UiO-66 (bottom). UiO Wavenumber (cm -1 ) Figure S5. DRIFTS spectra of (top) and UiO-66 (bottom). 4

5 UiO-66 Figure S6. SEM images of and UiO ph Run 1 Run 2 Run Volume NaOH (ml) Figure S7. Overlay of three acid base titration curves for activated showing reproducibility between samples. Average missing linker was calculated to be 1.62 missing linker/node which is very similar to Zr-UiO-66 synthesized with HCl (1.6 missing linker/node). 2 All missing linkers are assumed to be replaced with 2 H2O molecules and 2 OH groups. 5

6 Table S1. Calculated pka values for and UiO-66 based on titration curves. MOF pka1 pka2 pka3 µ3-oh -OH2 -OH 3.46± ± ±0.11 Zr-UiO ± ± ± Hydrolysis in water Conversion (%) CeBDC_1.5umol/PEI_7.5 mg CeBDC_1.5umol/PEI_10 mg CeBDC_1.5umol/PEI_15 mg Figure S8. Hydrolysis profiles of DMNP using (1.5 µmol) and different amounts of PEI (MW: 2,500) in water. 6

7 UiO ln(reaction conversion) Equation t 1/2 = 8 min linear fit y = a + b*x Adj. R-Squar Value Standard Err Intercept Slope ln ( reaction conversion) Equation y = a + b*x Adj. R-Square Value Standard Error UIO-66 Intercept UIO-66 Slope t 1/2 = 18.8 min UIO-66 Linear fit Figure S9. Kinetic plots showing the reaction of DMNP with and UiO-66 in buffer solution. Initial half-life (t1/2) was calculated by plotting the natural log of the conversion versus time; the slope (k) is related to the half-life by t1/2 = ln 2/k ln (reaction conversion) Equation y = a + b* Adj. R-Square Value Standard Error H Intercept H Slope t 1/2 = 3 min 0.5 Linear Fit Figure S10. Kinetic plot showing the reaction of GD with in buffer solution. 7

8 Conversion (%) mol% cat. loading 36 mol% cat. loading Figure S11. Hydrolysis profiles of DMNP using 1.5 µmol (6 mol% catalyst loading; open circules) and 9 µmol (36 mol% catalyst loading; solid circules) of Ce(NH4)2(NO3)6 in buffer solution. ZrCl4 solution did not show any activity under the same conditions. References 1. Lammert, M.; Wharmby, M. T.; Smolders, S.; Bueken, B.; Lieb, A.; Lomachenko, K. A.; Vos, D. D.; Stock, N., Chem. Commun. 2015, 51, Klet, R. C.; Liu, Y.; Wang, T. C.; Hupp, J. T.; Farha, O. K., J. Mat. Chem. A 2016, 4,