Subscriber access provided by University of Florida | Smathers Libraries
Communication
Removal of Nerve Agent Simulants from Water using Light-Responsive Molecular Baskets Sarah E Border, Radoslav Z Pavlovic, Lei Zhiquan, and Jovica D. Badjic J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.7b11960 • Publication Date (Web): 07 Dec 2017 Downloaded from http://pubs.acs.org on December 7, 2017
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 free 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 accessible to all readers and 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.
Journal of the American Chemical Society 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 6 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
Journal of the American Chemical Society
Removal of Nerve Agent Simulants from Water using LightResponsive Molecular Baskets Sarah E. Border, Radoslav Z. Pavlović, Lei Zhiquan and Jovica D. Badjić* The Ohio State University, Department of Chemistry & Biochemistry, 100 West 18th Avenue, Columbus, Ohio 43210
Supporting Information Placeholder ABSTRACT: We found that molecular baskets 1−3, with
amino acids at their rim, undergo photoinduced decarboxylations to give baskets 4−6 forming a solid precipitate in water. Furthermore, organophosphonates 7−9 (OP), akin in size and shape to G-type nerve agents, form inclusion complexes with baskets 1−3 (K = 6−2243 M-1). Light irradiation (300 nm) of an aqueous solution of 1−3⊂OP led to the formation of precipitate containing an OP compound thereby amounting to a novel strategy for light-induced sequestration of nerve agents or, perhaps, other targeted compounds. Importantly, the stability of basket⊂OP complexes in addition to functional groups at the basket’s rim play a role in the efficiency (up to 98%) by which OPs are removed from water.
reoisomeric compounds to complete chiral resolutions.11 Evidently, materials capable of selective and rapid sequestration of toxic substances employ the process of inclusion complexation12 to achieve their function.13 In this study, however, we probed light as a stimulus14 for triggering and thereby controlling the action of molecular baskets15 as scavengers of nerve agents in water (Figure 1).16 In brief, we found that light can induce the precipitation of OP substances trapped in the cavity of baskets, which, we posit, could have a broad scope of applications for removal of a variety of targeted compounds. (A)
+
-O C 2
G and V-type chemical warfare agents are small organophosphorus (OP) compounds1 that in minute quantities inhibit the action of acetylcholinesterase in neuromuscular junctions causing seizures, asphyxiation and death.2 For the rapid sequestration of these toxic substances, the action of enzymatic bioscavengers is being optimized,3 yet there exists a need for artificial scavengers4 capable of trapping OPs5 in addition to encapsulation catalysts with a mode of action akin to enzymes.6 Likewise, chemists have also been interested in the selective removal as well as detection of pharmaceuticals, metals, pesticides, detergents and other toxic chemicals,7 as an increasing occurrence of these micropollutants in ecosystems8 is expected to have an adverse effect on human health. In this regard, activated and mesoporous carbons9 continue to serve as effective adsorbents of organic micropollutants from contaminated water. Moreover, Dichtel and coworkers have developed10 mesoporous β-cyclodextrin polymers as an alternative for cleaning aqueous systems. These polyvalent structures are capable of rapidly extracting organic micropollutants whose size and shape are complementary to the cavity of the polymerized host. In a similar fashion, one could use β-cyclodextrins to induce precipitation of ste-
R N
O
O
hν 300 nm Water
3 CO2
hν 300 nm Water
3 CO2
O
O
CO2- O
CO2-
N
N
R
R
O
H CH3
1 2
CH(CH3)2
3
R
Precipitation and Removal of OPs? (B)
O CO2N R
O
O
-
*
-
O O
N
300 nm
N R
O
R
O O-
O
H+
N
N R
R
R O
CO2
O
O
N O
O
O
hν
O
Figure 1. (A) Chemical structure of baskets 1−3 with energy minimized 1 (MMFFs, Spartan) trapping a molecule of dimethyl methylphosphonate, in its inner space. Photochemical decarboxylation of basket⊂OP complex is hypothesized to reduce its solubility and thereby cause removal of the encapsulated OP compound from solution. (B) A plausible mechanistic scheme (akin to Curtin-Hammett situation) for photoinduced decarboxylation of phthalimide derivatives of amino acids.
ACS Paragon Plus Environment
Journal of the American Chemical Society
Molecular baskets 1−3 (Figure 1A) possess a flat aromatic base, which is fused to three bicyclic rings to form a curved unit.15 Three phthalimides extend this curvature into a C3 symmetric cavitand, carrying amino acid substituents with three carboxylates rendering the hydrocarbon scaffold soluble in water.17 Due to the hydrophobic effect,18 baskets are capable of trapping small organophosphorus (OP) compounds whose size and shape correspond to G and V-type nerve agents (Figure 1A).17 The binding affinities Kd span from mM to µM, depending on the basket’s size and functional R groups at its periphery.18-19 Since amino-acid functionalized phthalimides have been known to undergo photoinduced decarboxylations20 (i.e. photo-Kolbe reaction,21 Figure 1B) in aqueous media, we wondered: will irradiating baskets of type 1−3 (Figure 1A), each carrying three phthalimide chromophores,21 trigger their decarboxylation and precipitation in water? If 1−3 hold an OP guest in their cavity, however, will the photoinduced decarboxylation result in the removal of the complexed OP compound from solution (Figure 1A) to, perhaps, amount to a method for mild and selective sequestration of OPs transiently trapped in the cavity of baskets? First, we prepared baskets 1−3 carrying glycine, alanine and valine amino acids (Figure 1A) with increasingly sized/branched R groups at the rim.22 Irradiation (300 nm) of aqueous solutions of 1−3 (3.0 mM; 10.0 mM phosphate buffer at pH = 7.0) was monitored with 1 H NMR spectroscopy (Figure 2A/B; Figures S10−S12) to result in the disappearance of the reactant and concurrently the appearance of a white precipitate (Figure 2B/C). The change in the concentration of 1−3 with exposure time (showing a sigmoidal dependence, Figure 2C) was quantified by using (CH3)4NBr (TMAB) as an internal standard with the apparent half time for 1−3 decreasing from c.a. 200 to 110 min. Upon isolation of the solid precipitate by centrifugation, we dissolved it in CDCl3 and examined with 1H/13C NMR spectroscopy to find the sole formation of fully decarboxylated baskets 4−6 (Figure 2A; see also Figures S4-S9); on the basis of 1 H NMR spectroscopy 4−6 are practically insoluble in water. In line with these results, we reasoned that singly or doubly decarboxylated 1−3 appear in small concentrations during the transformation. To additionally study this matter, we stopped the photochemical conversion of 3 into 6 before its completion (60% of 3 remaining, Figure 2D) and added strong acid (HCl) to, via protonation of carboxylates, promote the precipitation of all organics in water. 1H NMR spectrum of the precipitate, dissolved in CD3SOCD3, showed two sets of signals corresponding to 3 and 6 in the ratio 60:40 (Figure 2Dd). 1H NMR spectrum of the aqueous layer, however, showed no presence of organics except TMAB. Since 60:40 ratio of 3 and 6 is in agreement with 60% of 3 remaining at the end of irradiation (Figure 2Db) we conclude that the
conversion of 3 to 6 takes place with a trace (if any) quantity of intermediates. The apparent absence of (A) Hc Hb
O
1-3
N Hd/e
O
O
CO2R Ha
hν, 300 nm H 2O pH = 7.0 CO2
R 4 H 5 CH3 R CH(CH3) 6
N O (C)
(B) TMAB
hν
Hb
Hc
Ha
Hd/e
300 nm
3.0
Concentration 1-3 (mM)
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
Page 2 of 6
1 2 3
2.5 2.0 1.5 1.0 0.5 0 0
200
400 600 time (min)
800
1000
7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 δ (ppm) time (0-996 min) (D ) Hd Hc
O
Hd Hc
CO2-
N
3 He/f
H Hb CH a 3 O
hν,300 nm H 2O pH = 7.0 CO2
Hc
Hd
Hb
O N
He/f
O
Hb Ha CH3
6
CH3
TMAB He/f * *
Ha
(a) (b)
Hc
Hd
Hc
Hd
Hb
He/f
(c) (d) (e)
Hb
CH3
Ha
He/f
Ha
CH3
8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 δ (ppm)
Figure 2. (A) Chemical structure of baskets 4−6 obtained from 1−3 after light-induced expulsion of CO2. (B) Irradiation (300 nm, Rayonet) of basket 1 (3.0 mM) dissolved in 10.0 mM phosphate buffer at pH = 7.0 was monitored with 1 H NMR spectroscopy (600 MHz, 298 K) using TMAB as an internal standard; note that the NMR tube holding the reactant had to be removed from the reactor for recording each spectrum. (C) Change in the concentration of 1−3 with time (1H NMR spectroscopy) was fitted to a sigmoidal function (SigmaPlot). (D) 1H NMR spectra (600 MHz, 298 K) of basket 3 (3.0 mM) in 10 mM phosphate buffer (pH = 7.0) before (a) and after 70 min (b) of irradiation (300 nm, Rayonet). 1H NMR spectra (600 MHz, 298 K) of 3 (c), a mixture of precipitated 3/6 (d) and 6 (e) in CD3SOCD3.
partially decarboxylated 1−3 is for our polyvalent system surprising and, perhaps, not fully in line with the mechanism of light-induced decarboxylation of monovalent phthalimides (Figure 1B); the decarboxylation of phthalimides was shown to include20c a rapid formation of the excited triplet state of the phthalimide chromophore, which acts as a good electron acceptor to receive an electron from the neighboring carboxylate followed by the removal of CO2. In the case of polyvalent 1−3, however, the excited state of baskets may trigger a cascade of decarboxylations to give 4−6 via short-lived intermediates containing one/two carboxylate groups. Additional mechanistic studies are in order since partly decarboxylated hosts are expected to possess different propensities for trapping OPs affecting the process of sequestration (see below).22
ACS Paragon Plus Environment
Page 3 of 6 (A)
(B)
O O
O
P O
O
O
P O
O
P O
7
119
9
185
197
δ Ha (ppm)
3.9 8
Volume (A3)
3.8 3.7 3.6 0
-PC6H5
Ha
5
10 15 20 25 Guest 9 (mM)
30
0.8 -OCH3
Δδobs (ppm)
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
Journal of the American Chemical Society
-OCH3
0.6 0.4
-PC6H5
0.2
1 9 0.0 0
5
10 15 20 25 Guest 9 (mM)
30
Figure 3. (A) Chemical structures of OPs 7−9 and their computed volumes. (Bottom) Energy-minimized structure (MMFFs, Spartan) of 1⊂9 complex. (B) Nonlinear leastsquare analysis (Sigma Plot) of 1H NMR binding data (1:1 binding stoichiometry) corresponding to the formation of 1⊂9 gave the association constant K = 2243 ± 89 M-1. The titration was completed at 298 K by the addition of 9 (50 mM) to basket 1 (0.32 mM) dissolved in 10 mM phosphate buffer at pH = 7.0. (Bottom) Normalized 1H NMR chemical shifts of O−CH3 and P−C6H5 protons from 9 obtained from the titration experiment (Figure S15).
To quantify the affinity of 1−3 for trapping differently sized OPs 7−9 in water (119−197 Å3, Figure 3A), we completed a series of 1H NMR spectroscopic titrations (Figure 3B, Figures S13-S21). All encapsulations (in/out exchange of guests) occurred rapidly on the NMR time scale (ms) giving rise to a single set of resonances for both baskets and OPs.23 The complexation data was subjected to nonlinear least-squares analysis using models describing the formation of 1:1 and 1:2 host−guest complexes.24 The computed binding isotherms (Figure 3B; Figures S13-S21) were in reasonable agreement (using the distribution of residuals)25 with the predominant formation of binary 1:1 complexes having a broad range of thermodynamic stabilities (K = 6 − 2243 M-1; Table 1); note that in cases where the formation of ternary complexes was observed, K1>>K2. Evidently, basket 1 with R = H at its rim possesses higher while basket 3 with R = CH(CH3)2 lower affinities for trapping 7−9. Indeed, this trend was noted earlier:22 as Table 1. Thermodynamic stability (K, M-1) of complexes of baskets 1−3 and OPs 7−9 in water (10 mM phosphate buffer at pH = 7.0) were determined with 1H NMR spectroscopy (298 K, Figures S13-S21).
K (M-1) Guest 7 Guest 8 Guest 9
Basket 1 405 ± 14a 768 ± 51 2243 ± 89
Basket 2 73 ± 4a 181 ± 9b 822 ± 16
Basket 3 5.5 ± 0.1a 24 ± 2b 64 ± 2b
a See ref. 22 for experimental details. bThe binding isotherms would, in these cases, fit better to 1:2 complexation model with: K1 = 181 ± 9 M-1/K2 = 12 ± 1 M-1 for 2⊂8, K1 = 24 ± 2 M-1/K2 = 3 ± 3 M-1 for 3⊂8 and K1 = 64 ± 2 M-1/K2 = 1.6 ± 0.1 M-1 for 3⊂9.
the size/branching of R groups on the host increases (viewing data from left to right in Table 1), the complexation affinity toward each guest drops due to steric host/guest interactions at the baskets’ top perimeter. The affinity of each basket toward 7−9, however, grows (viewing data from top to bottom in Table 1) as the guest size changes. In this regard, the magnetic perturbation (diamagnetic shielding) of P−CH3 nuclei was in 1⊂7 found1 to be greater than O−CH3 nuclei, which indicates that P−CH3 populates the cup shaped aromatic cavity (Figure 1A). For guest 9 complexing 1, however, there is a greater magnetic shielding of its O−CH3 (Δδobs = 0.78 ppm, Figure 3B) than P−C6H5 nuclei (Δδobs = 0.37 ppm, Figure 3B) so that this molecule prefers anchoring one of its methoxy groups in the aromatic cavity of the host.19b It follows that different docking positions of 7 (Figure 1A) and 9 (Figure 3A) inside 1 originate from different complementarities26 of these host-guest pairs, which in turn could have an effect on their observed order of stability. Lastly, we prepared 3.0 mM solutions of 1−3 in 10.0 mM phosphate buffer at pH = 7.0 containing 7−9 (c.a. 0.6 mM) so that we have both complexed and free molecules in solution in proportions corresponding to equilibrium constants. Each solution was subjected to 300 nm light irradiation (Rayonet) at 298 K. All reactions were monitored with 1H NMR spectroscopy (31P NMR spectroscopic measurements are less sensitive) to show the disappearance of both baskets and OP guests (Figure S22-S30) and the concurrent formation of white precipitate; for additional details about examining the host guest precipitate, see Figure S31. Interestingly, the apparent reduction in the concentration of 7−9 with time in each basket showed a sigmoidal dependence with different quantities of OP molecules removed from water (Figure 4A/B/C); note that 7−9 are photostable (Figures S32-S34). Markedly, compound 9 (0.6 mM) was in the presence of 1 (3.0 mM) practically removed (98%, Figure 4A) from its water solution (Figure 4A) after irradiation! The precipitated amounts of guests 8 (80%) and 7 (42%) were, however, smaller. Since the stability constants corresponding to the formation of 1⊂7 (K = 405 M-1), 1⊂8 (K = 768 M-1) and 1⊂9 (K = 2243 M-1) are in order with the degree of precipitation, there may exist a correlation that is in line with a Curtin-Hammett mechanistic scenario27 (Figure 1A) in which the greater the Ka the more of the OP is being removed; note that the lightinduced removal of basket or basket-guest complexes is probably an irreversible process (Figures S35-S38). The overall dependence for all nine host-guest pairs is furthermore shown in Figure 4D. A greater affinity (K) of baskets toward OPs will, to a first approximation, lead to more effective removal of OPs. To additionally analyze the situation, however, we used dotted lines (Figure 4D) to visualize the potency by which each basket 1−3, carrying differently sized groups at the rim (Figure 4E),
ACS Paragon Plus Environment
Journal of the American Chemical Society
removes OPs from water. Apparently, the “slopes” of the three “saturation” curves corresponding to the operation of 1−3 are different, to suggest that their relative “capacity” to remove OPs could be in order 3>2>1. That is to say, basket 3 (with the greatest slope) should, allegedly, reach its maximum working capacity (i.e. 100% removal of OPs) within a narrow range of K’s! On the other hand, basket 1 is less efficient requiring a greater range but also higher K values for reaching its full potential. It therefore appears that hydrophobic groups at the rim of 3 (Figure 4E) amplify the guest precipitation during the phase transition. (B)
(A) Basket 1
0.5 42%
7
0.3 0.2
80%
8
0.1
Concentration 7−9 (mM)
Concentration 7−9 (mM)
0.6
0.4
98% 9 100 (C)
300
500 700 Time (min)
24%
0.5
7
55%
0.2 84%
0.1
9
100 200 300 400 500 600 700 800
0.5 0.4
13%
44%
7 8
0.3 0.2
66%
9
0.1
7−9 removed from solution (%)
(D) Basket 3
90 80
Basket 1
70 60 50 40 30 20
7
Basket 2
8 9
Basket 3
10
50 100 150 200 250 300 350 400 Time (min)
0
0.25 0.5 0.75 1 1.25 1.5 1.75 2 K a x 10 3 (M -1)
(E)
1
2
Supporting Information Additional experimental details and protocols. The Supporting Information is available free of charge on the ACS Publications website.
Corresponding Author
8
900
0.6
ASSOCIATED CONTENT
[email protected] 0.4 0.3
with both spatial and temporal control.2 Accordingly, we are examining the scope and mechanistic details of our photochemical procedure for completing rapid and stimuli-responsive sequestration of nerve agents, pesticides and other toxic compounds with amino-acid functionalized baskets in both living systems and the environment.
AUTHOR INFORMATION
Basket 2
0.6
Concentration 7−9 (mM)
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
3
R Group Size
Figure 4. A light-induced (300 nm) change in the concentration of organophosphonates 7, 8 and 9 in solution (10 mM phosphate buffer at pH = 7.0) of 3.0 mM baskets 1 (A), 2 (B) and 3 (C) was monitored with 1H NMR spectroscopy at 298 K; for longer monitoring times, see Figures S35-37. (D) The proportion (%) of 7−9 removed from the solution of 1−3 as a function of the corresponding stability constants (these proportions were also shown on plots A, B and C). (E) Top view of energy-minimized (MMFFs, Spartan) baskets 1, 2 and 3 holding guest 7.
In summary, molecular baskets with three carboxylates at their rim and OP molecules occupying their inner space undergo photoinduced decarboxylations and precipitation to remove OPs from solution. The degree of sequestration is proportional to the stability of basket⊂OP complex and the nature (hydrophobicity) of functional groups at the rim of baskets. Since OPs used in our study are akin in size and shape to G-type nerve agents, the strategy reported here could, perhaps in future, be applied toward removal of chemical warfare agents under mild conditions and from aqueous systems
ACKNOWLEDGMENT This work was financially supported with funds obtained from National Science Foundation under CHE-1606404.
REFERENCES (1) Ruan, Y.; Taha, H. A.; Yoder, R. J.; Maslak, V.; Hadad, C. M.; Badjic, J. D. J. Phys. Chem. B 2013, 117, 3240. (2) Kim, K.; Tsay, O. G.; Atwood, D. A.; Churchill, D. G. Chem. Rev. 2011, 111, 5345. (3) Nachon, F.; Brazzolotto, X.; Trovaslet, M.; Masson, P. Chem.Biol. Interact. 2013, 206, 536. (4) Zengerle, M.; Brandhuber, F.; Schneider, C.; Worek, F.; Reiter, G.; Kubik, S. Beilstein J. Org. Chem. 2011, 7, 1543. (5) Sambrook, M. R.; Notman, S. Chem. Soc. Rev. 2013, 42, 9251. (6) Katz, M. J.; Mondloch, E.; Totten, R. K.; Park, J. K.; Nguyen, S. B. T.; Farha, O. K.; Hupp, J. T. Angew. Chem., Int. Ed. 2014, 53, 497. (7) Teresa Albelda, M.; Frias, J. C.; Garcia-Espana, E.; Schneider, H.J. Chem. Soc. Rev. 2012, 41, 3859. (8) (a) Malaj, E.; von der Ohe, P. C.; Grote, M.; Kuehne, R.; Mondy, C. P.; Usseglio-Polatera, P.; Brack, W.; Schaefer, R. B. Proc. Natl. Acad. Sci. U. S. A. 2014, 111, 9549; (b) Luo, Y.; Guo, W.; Ngo, H. H.; Nghiem, L. D.; Hai, F. I.; Zhang, J.; Liang, S.; Wang, X. C. Sci. Total Environ. 2014, 473-474, 619. (9) Dias, J. M.; Alvim-Ferraz, M. C. M.; Almeida, M. F.; RiveraUtrilla, J.; Sanchez-Polo, M. J. Environ. Manage. 2007, 85, 833. (10) Alsbaiee, A.; Smith, B. J.; Xiao, L.; Ling, Y.; Helbling, D. E.; Dichtel, W. R. Nature 2016, 529, 190. (11) Bakirci, H.; Nau, W. M. J. Org. Chem. 2005, 70, 4506. (12) Hof, F.; Craig, S. L.; Nuckolls, C.; Rebek, J., Jr. Angew. Chem., Int. Ed. 2002, 41, 1488. (13) Liu, W.; Samanta, S. K.; Smith, B. D.; Isaacs, L. Chem. Soc. Rev. 2017, 46, 2391. (14) Qu, D.-H.; Wang, Q.-C.; Zhang, Q.-W.; Ma, X.; Tian, H. Chem. Rev. 2015, 115, 7543. (15) Hermann, K.; Ruan, Y.; Hardin, A. M.; Hadad, C. M.; Badjic, J. D. Chem. Soc. Rev. 2015, 44, 500. (16) Jin, H.; Zheng, Y.; Liu, Y.; Cheng, H.; Zhou, Y.; Yan, D. Angew. Chem., Int. Ed. Engl. 2011, 50, 10352. (17) Ruan, Y.; Peterson, P. W.; Hadad, C. M.; Badjic, J. D. Chem. Commun. 2014, 50, 9086. (18) Zhiquan, L.; Polen, S. M.; Hadad, C. M.; RajanBabu, T. V.; Badjic, J. D. Org. Lett. 2017, 19, 4932. (19) (a) Chen, S.; Ruan, Y.; Brown, J. D.; Hadad, C. M.; Badjic, J. D. J. Am. Chem. Soc. 2014, 136, 17337; (b) Ruan, Y.; Chen, S.; Brown, J. D.; Hadad, C. M.; Badjic, J. D. Org. Lett. 2015, 17, 852. (20) (a) Sato, Y.; Nakai, H.; Mizoguchi, T.; Kawanishi, M.; Hatanaka, Y.; Kanaoka, Y. Chem. Pharm. Bull. 1982, 30, 1263; (b) Soldevilla, A.; Griesbeck, A. G. J. Am. Chem. Soc. 2006, 128, 16472; (c)
ACS Paragon Plus Environment
Page 4 of 6
Page 5 of 6 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
Journal of the American Chemical Society Warzecha, K.-D.; Goerner, H.; Griesbeck, A. G. J. Phys. Chem. A 2006, 110, 3356. (21) Griesbeck, A. G.; Kramer, W.; Oelgemoller, M. Synlett 1999, 1169. (22) Ruan, Y.; Dalkilic, E.; Peterson, P. W.; Pandit, A.; Dastan, A.; Brown, J. D.; Polen, S. M.; Hadad, C. M.; Badjic, J. D. Chem. Eur. J. 2014, 20, 4251. (23) Rieth, S.; Hermann, K.; Wang, B.-Y.; Badjic, J. D. Chem. Soc. Rev. 2011, 40, 1609.
(24) Brynn H. D.; Thordarson, P. Chem. Commun. 2016, 52, 12792. (25) Ulatowski, F.; Dabrowa, K.; Balakier, T.; Jurczak, J. J. Org. Chem. 2016, 81, 1746. (26) Wittenberg, J. B.; Isaacs, L. Supramol. Chem. Mol. Nanomater. 2012, 1, 25. (27) Seeman, J. I. J. Chem. Educ. 1986, 63, 42.
ACS Paragon Plus Environment
Journal of the American Chemical Society 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
Nerv
e Ag
Page 6 of 6
ent
hν 3 CO2
Soluble
Insoluble
Table of Contents
ACS Paragon Plus Environment
6
