Research Article pubs.acs.org/acscatalysis
Supported Aluminum Catalysts for Olefin Hydrogenation Jeffrey Camacho-Bunquin,*,† Magali Ferrandon,† Ujjal Das,† Fulya Dogan,† Cong Liu,† Casey Larsen,† Ana E. Platero-Prats,†,‡ Larry A. Curtiss,† Adam S. Hock,†,§ Jeffrey T. Miller,∥ SonBinh T. Nguyen,†,⊥ Christopher L. Marshall,† Massimiliano Delferro,† and Peter C. Stair*,†,⊥ †
Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States § Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois 60616, United States ∥ Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States ⊥ Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States ‡
S Supporting Information *
ABSTRACT: Three-coordinate alkylaluminum sites were developed on a catechol-containing porous organic polymer support (CatPOP A2B1). The CatPOP-based alkylaluminum sites were characterized by solid-state attenuated total reflectance IR spectroscopy, 1H and 27Al magic-angle-spinning NMR spectroscopy, pair-distribution function X-ray absorption spectroscopy, and elemental analysis. The low-coordinate organoaluminum sites can hydrogenate and isomerize a range of mono- and disubstituted alkenes and alkynes under mild conditions (75−100 °C, 5−14 bar H2, 20 h). Results of experimental and computational mechanistic investigations suggest a heterolytic mechanism for the observed hydrogenation−isomerization activity. KEYWORDS: alkene hydrogenation, organoaluminum, porous organic polymer, surface organometallics, heterogeneous catalysis conditions (>200 °C, >100 bar H2); however, the nature of the active catalysts remains ill-defined.8a The breadth of literature on aluminum-mediated transfer hydrogenation reactions and other Al−H-mediated reductive transformations suggests that purposeful design of Al coordination could result in active reduction catalysts.9 Stephan and co-workers recently reported the catalytic hydrogenation of imines with freely soluble AliBu3 under comparable conditions (10−20 mol % Al, > 100 °C, 100 bar H2) and proposed a two-step mechanism proceeding through (1) CN bond hydroalumination and (2) Al−N bond hydrogenolysis.8b In this report, we present an active-site design motif that imparts transition-metal-like hydrogenation activity to maingroup Lewis acids. Specifically, we report the development of isolated, low-coordinate alkylaluminum sites supported on a catechol-containing porous organic polymer (CatPOP A2B1) that catalytically hydrogenate alkyl- and aryl-functionalized alkenes and alkynes under relatively mild conditions (75 °C, 5 bar H2).10 These well-defined alkylaluminum sites exhibit recyclability and higher reactivity compared with their
R
ational design of catalytic sites for the hydrogenation of unsaturated functionalities has been largely based on established metal-mediated hydrogenation mechanisms.1 While purposeful design of hydrogenation catalysts is more established with base2 and precious3 transition metals, such cannot be said for main-group elements because of the scarcity of representative strategies. The emergence of frustated Lewis pair (FLP) catalysts resulted in increased attention to maingroup-element-mediated hydrogenation.4 FLPs, operating via bifunctional activation of hydrogen, hydrogenate a range of unsaturated functional groups, including electron-rich/-poor alkenes5 and polar unsaturated moieties.6 Despite the broad scope of substrates, FLPs are mostly unreactive toward purely aliphatic alkenes. A few non-FLP main-group catalysts have been shown to be active toward aliphatic alkene hydrogenation.7,8 Wang and co-workers reported that electrophilic organoboranes (e.g., (F5C6)2B−H) hydrogenate aliphatic alkenes (10−20 mol % B, 6 bar H2, 140 °C) via a two-step mechanism involving (1) alkene hydroboration and (2) C(alkyl)−B bond hydrogenolysis.7 Compared with boron, the manipulation of aluminum coordination environments for catalytic hydrogenation with molecular hydrogen as the reductant is far less explored. Molecular organoaluminum species (e.g., AliBu3, HAliBu2) hydrogenate mono- and dialkylated alkenes under severe © XXXX American Chemical Society
Received: September 28, 2016 Revised: November 29, 2016 Published: December 5, 2016 689
DOI: 10.1021/acscatal.6b02771 ACS Catal. 2017, 7, 689−694
Research Article
ACS Catalysis
out via X-ray photoemission spectroscopy (XPS), X-ray pair distribution function (PDF) studies, solid-state attenuated total reflectance Ir (ATR-IR) spectroscopy, 1H and 27Al magic-anglespinning (MAS) NMR spectroscopy, and ligand-displacement experiments. XPS characterization confirmed the trivalent state of aluminum in both systems (SI, Figure S6). X-ray differential pair distribution function (dPDF) studies on 2 and 3 confirmed the alumination of the CatPOP support. PDF features corresponding to Al−X bonds (X = O and/or C) at ∼1.95 Å were observed (SI, Figures S11−S12). Additionally, PDF data showed no new distances corresponding to Al−Al dimers, consistent with the single-site nature of the Al(III) centers in both systems. Infrared spectroscopy confirmed the presence of Al−C(alkyl) groups in both systems. Specifically, 2 and 3 show strong absorptions at 685 and 687 cm−1, respectively (Figure 2a), characteristically indicative of terminal Al−C(alkyl)
pyrophoric molecular congeners. Mechanistic studies revealed a heterolytic hydrogenation mechanism. Our study was motivated by the results of gas-phase catalyst synthesis and testing using an integrated atomic layer deposition−catalysis (I-ALD-CAT) tool developed in our group.11 One-cycle grafting of trimethylaluminum (TMA) on silica at 175 °C afforded supported methylaluminum sites (SiO2-Al-Me) that hydrogenate propylene under plug-flow conditions at 75 to 100 °C (see Supporting Information (SI) section 1). During the hydrogenation catalysis, the period of active propylene hydrogenation coincides with the detection of methane in the product stream, presumably via the hydrogenolysis of Al−CH3 groups. Prior reports on the grafting of TMA on oxide supports reveal the formation of a multitude of sites and the dynamic nature of these supported alkylaluminum species,12 making structure−hydrogenation activity correlation extremely challenging.13 Copéret and co-workers recently reported that tricoordinate Al(III) defect sites on activated γAl2O3 activate X−H bonds (X = H, CH3).14 These lowcoordinate Al sites on γ-Al2O3 surfaces could be the active catalytic sites responsible for the ethylene hydrogenation activity that Hindin and Weller reported six decades ago.15 Alternatively, Ozin and co-workers recently demonstrated that coordinatively unsaturated surface indium sites adjacent to a Lewis-basic surface hydroxide could form FLP sites that photocatalytically hydrogenate CO2.16 These studies suggest that supported coordinatively unsaturated main-group sites may be responsible for the observed reactivity of SiO2-Al-Me. Hence, our group purposefully developed low-coordinate alkylaluminum sites on a single-site support, CatPOP A2B1. CatPOP A2B1, a catecholate-containing porous organic polymer, is a polymeric support with oxygenated binding sites that allow to support10,17 isolated low-coordinate, monomeric organometallic species that are typically unstable in solution. The isolation of the catecholate site on CatPOP provides a unique ligand coordination environment that prevents bimolecular decomposition pathways. Exposure of a hexanes solution of AlR3 (R = iBu, CH3) to a stoichiometric amount of CatPOP A2B1 (1) affords precatalysts 2 [CatPOP-Al-iBu] and 3 [CatPOP-Al6(CH3)8] (Figure 1).
Figure 2. (a) Fingerprint region of the infrared spectra of 2 and 3 and the latter’s catechol and Bpy derivatives. Also shown are the respective solid-state (b) 1H and (c) 27Al MAS NMR spectra of 3 and its derivatives (mass normalized). The 1H MAS NMR chemical shifts for 3 at δ = 0.8 ppm (CH2) and 0.3 ppm (CH3) are due to solvent molecules entrapped in the CatPOP framework. A more detailed discussion of the spectral data is provided in the Supporting Information.
groups18 and consistent with density functional theory (DFT)-predicted terminal Al−C stretching frequencies (Table S2). The presence of Al−alkyl groups was also confirmed via protonolysis experiments; treatment with excess molecular catechol and exposure to air (Figure 3) resulted in the disappearance of the terminal Al−alkyl IR features (Figure 2a). Moreover, treatment with the polar aprotic ligand 2,2′bipyridine (Bpy) resulted in a derivative in which the Al−alkyl IR feature is conserved. The solid-state 1H MAS NMR spectra of 2 and 3 show signals attributable to Al−iBu (δ = 0.8 ppm (CH2) and 0.3 ppm (CH3)) and Al−CH3 (δ = 0 to −3 ppm (CH3)) groups, respectively (Figure 2b), consistent with the chemical shifts reported by Basset and co-workers on well-defined silicasupported isobutylaluminum species.12 The 27Al MAS NMR spectra of both precatalysts do not show any pronounced 27Al peak (Figure 2c), consistent with the presence of tricoordinate aluminum. DFT calculations of the NMR isotropic chemical shifts and quadrupolar coupling constants were carried out for selected Al model compounds (SI, Table S6). The tricoordinate Al sites in 2 and 3 were predicted to occur at 160 and 165 ppm,
Figure 1. Metalation reaction between AlR3 and CatPOP A2B1 (1). Complete metalation of 1 is achieved with 1−1.3 equiv of AlR3 per catechol unit (for details, see the Supporting Information).
Self-limiting, quantitative metallation of catechol units in 1 is achieved with 1 and 1.3 equiv of AliBu3 and AlMe3, respectively (see SI section II). Elemental analyses confirmed monoalumination of each catechol unit with AliBu3, while metallation with TMA affords a ∼ 4:1 mixture of monoaluminated (3a) and dialuminated (3b) catecholates. This difference in metallation selectivity is attributed to the respective solution-phase nuclearities of the precursors: AliBu3 is monomeric13a while AlMe3 is oligomeric,13b with the latter kinetically favoring the formation of dialuminum sites (3b). Elucidation of the aluminum coordination environment in 2 and 3 was carried 690
DOI: 10.1021/acscatal.6b02771 ACS Catal. 2017, 7, 689−694
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Figure 3. Formation of higher-coordinate aluminum centers 4 (red) and 5 (blue) upon exposure of 3 to excess molecular catechol and air, respectively. The 27Al chemical shift for the catechol derivative 4 (δ = 30 ppm) is consistent with the predicted value (see SI section II). The airexposed material 5 shows an 27Al chemical shift at 5 ppm, characteristic of hexacoordinate Al(III) sites.
with quadrupolar coupling constant values (Cq) of 34 and 35 MHz, respectively (see models I and II in SI, Table S6). The lack of observable 27Al peaks in the NMR experiments can be attributed to the low-symmetry coordination and strong quadrupolar interactions arising from the quadrupolar nature of 27Al nuclei (S = 5/2).19 Stephan and co-workers reported a molecular three-coordinate carbene−alane complex that is similarly 27Al NMR-silent.20 Exposure of 2 and 3 to air or an excess of molecular catechol “healed” the low-symmetry threecoordinate aluminum sites to form six-coordinate Al(III) derivatives with intense 27Al peaks centered at 5 and 30 ppm, respectively (Figures 2c and SI, Figure S17), consistent with the DFT calculations (see model IV in SI, Table S6). The 27Al MAS NMR findings, coupled with IR data and the NMR-scale alumination reaction between CatPOP A2B1 and AliBu3, are the basis for the proposed Al coordination in 2 and 3: the Al(III) center is stabilized by a dianionic catecholate unit and an anionic alkyl group. Both 2 and 3 are active for hydrogenation of aliphatic and aryl-substituted alkenes and alkynes under mild conditions. Using a high-throughput batch reactor system and 1-octene (in dodecane) as the substrate, it was observed that 3 is more active than 2 over the range of conditions explored (1−15 mol % Al, 5−14 bar H2, 75−100 °C; for details, see SI section III). Optimum hydrogenation with 3 was observed with Al loadings of 8 mol % and higher at 75 °C and 14 bar H2 (96% conversion; octane (90%) and internal octenes (6%)). Hydrogenation is slower at lower H2 pressures (85% conversion, 8 mol % Al with 3 or 5 bar H2) and, surprisingly, at higher temperatures. Experiments at 100 °C (14 bar H2, 8 mol % Al) effected 75% conversion to a mixture of internal octenes (60%) and octane (15%). The lower hydrogenation rate and increased selectivity to internal olefins at elevated temperatures are presumably due to higher β-H transfer/ elimination rates. The lower activity of 2 (SI, Figures S18−S19) is attributed to the steric encumbrance of the Al by bulkier isobutyl groups. Under the conditions explored, the nonmetallated CatPOP support does not react, while the molecular precursors AlMe3 and AliBu3 effect stoichiometric conversions; molecular catecholate−AlMe,21 which is generally oligomeric in solution, is completely unreactive. Replacement of the H2 atmosphere with N2 gave only isomerization products (20 to 30% conversion) in the presence of either 2 or 3 (Table S1). Both precatalysts can be stored in an air- and moisture-free environment for 6 months with very little decrease in catalytic activity. Exposure to air results in loss of catalytic activity. The relative reactivities of the more active catalyst 3 toward alkenes and alkynes with varying degrees of substitution were evaluated under identical testing conditions (9 mol % Al, 75 °C, 14 bar H2, 20 h; Table 1). Catalyst 3 hydrogenates aliphatic alkenes (entries A−C). 1-Octene is quantitatively reduced to a
Table 1. Catalytic Hydrogenation of Aliphatic and Aromatic Alkenes and Alkynes Using 3 as the Precatalyst
a
Each hydrogenation experiment was carried out under batch reactor conditions using 9 mol % Al and 0.25 M substrates in dodecane at 75 °C and 14 bar H2 for 20 h.
mixture mainly composed of n-octane (97%). tert-Butylethylene, a nonisomerizable alkene, is hydrogenated to the corresponding alkane with 62% conversion and 100% selectivity (entry B). The lower conversion is attributed to its high volatility (bp = 41 °C), which limits its liquid-phase solubility. 2,3-Dimethyl-2-butene (entry C), a tetrasubstituted alkene, was hydrogenated at a much lower rate because of the sterically encumbered CC bond. Both 2 and 3 hydrogenate aryl-substituted alkenes and alkynes (see SI, Table S1 for hydrogenation studies with 2). Phenylacetylene, a terminal alkyne (entry D), is completely hydrogenated to styrene (73%) and ethylbenzene (27%), while the internal alkynes 1phenylpropyne and diphenylacetylene (entries E and F) are converted to mixtures composed of cis/trans-alkenes and the corresponding C2 alkane products. Substrates with a disubstituted vinyl carbon (1-phenylcyclohexene and 1,1-diphenyl691
DOI: 10.1021/acscatal.6b02771 ACS Catal. 2017, 7, 689−694
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ACS Catalysis ethylene; entries G and H) undergo substoichiometric hydrogenation, presumably because of the larger barriers to Al coordination with the sterically hindered vinyl carbons. Polar unsaturated groups (ketones and imines, entries I and J) do not react at all, consistent with the Lewis acidic nature of the active sites. In addition, catalytic hydrogenation is completely suppressed in aromatic hydrocarbon solvents such as toluene. Prior reports on trialkylaluminum grafting on oxide supports revealed that supported alkylaluminum fragments do not undergo protonolysis in ether and toluene as a result of the formation of stable Lewis acid−π adducts.13b The hydrogenation activity of 2 and 3 validates our activesite design motif for catalytic hydrogenation: coordinatively unsaturated monocatecholato monoalkyl Al(III) centers. We attribute the hydrogenation activity to low Al coordination that is not easily achieved with freely soluble monocatecholate Al(III) species. This is further confirmed by the inactivity of the higher-coordinated catechol, Bpy, and air-exposed derivatives.22 No aromatic ring hydrogenation was observed for phenylsubstituted substrates, thus ruling out metal-nanoparticlecatalyzed hydrogenation. Overall, alkene and alkyne dimerization/oligomerization products from radical-mediated pathways were not observed. At this point, the contributions of the redox-active catecholato ligand to the activity are still unclear; however, the hydrogenation activity of the SiO2-Al-R catalysts (vide supra) suggests that redox activity of the support is not a prerequisite (SI, Figures S20−S21). Catalytic deuteration of 1-octene was carried out to gain insights into the hydrogenation mechanism. Deuteration of 1octene with 3 (1 mol %, 75 °C, 14 bar D2 ) gave dideuterooctane C8H16D2 (10%; M+ = 116 by GC−MS) and a mixture of internal octenes (24%). Octene dideuteration is consistent with a two-step hydrogenation mechanism similar to the hydroalumination/C−N bond hydrogenolysis mechanism proposed by Stephan and co-workers.8b On the other hand, 1octene deuteration at 100 °C resulted in near-quantitative isomerization to monodeuterated internal octenes, consistent with the observed lower rate of 1-octene hydrogenation at 100 °C due to the competitive isomerization. One intriguing question is the mechanism of activation of hydrogen by precatalysts 2 and 3. The tricoordinate alkylaluminum sites in both systems can potentially activate hydrogen via σ-bond metathesis-like direct hydrogenolysis of the Al−C(alkyl) bond to give the corresponding alkane and an active Al−H intermediate (a → c; Figure 4). The importance of Al−C groups in the precatalyst to generate supported hydrogenation-active Al−H species was earlier demonstrated by Basset and co-workers on isobutylaluminum species supported on Al2O3, where the hydrogenolysis product Al−H was shown to be active for ethylene hydrogenation and polymerization.23 Wang et al.7 have shown this to be the main H2 activation pathway for highly electrophilic organoboranes with a B−C(alkyl) moiety. Alternatively, heterolytic H2 activation over an Al−O bond can generate a monoprotic catecholato backbone and a hydrido alkylaluminum species (a → b). The Al−C bond in b can then undergo protonation to generate the corresponding alkane and an active Al−H species. This mechanism is similar to the heterolytic activation of H−H and C−H bonds over a metal−oxygen bond proposed for supported transition (Cr3+, Fe2+, Co2+)24 and post-transition (Zn2+, Ga3+)25 metals, where the metal site acts as a Lewis acid catalyst. DFT calculations predict that the free energy barrier (ΔG⧧) for H2 activation over the Al−O bond in 3a is 34.2 kcal/
Figure 4. Probable hydrogenation mechanisms.
mol, nearly 16 kcal/mol lower than the corresponding barrier for H2 activation over the Al−C(alkyl) bond (50 kcal/mol), suggesting that the heterolytic H2 activation mechanism is kinetically more favorable. IR analysis of spent catalysts 2 and 3 showed no active aluminum hydride species; the characteristic IR features of both spent catalysts are very similar to those of 2, indicating that an aluminum-bound alkyl species (d) is the catalyst resting state (Figure 4; see the detailed IR spectra in SI, Figures S9 and S10), indicating potential catalyst recyclability. A three-cycle 1-octene hydrogenation test using both systems confirmed their recyclability (see SI, Figure S22), a feature that cannot be easily achieved with their pyrophoric and highly unstable molecular congeners. To gain further insight into the H2 activation mechanism, we carried out natural-bond-orbital (NBO) analyses of the corresponding transition states TS1 and TS2 (Figure 5).
Figure 5. Natural bond orbitals involved in charge transfer in the transition states for H2 activation over (a) the Al−O bond (TS1) and (b) the Al−C bond (TS2).
NBO analysis revealed significant two-way charge transfer in the transition states, from H2 to Al in 3 and vice versa, resulting in transition state stabilization. Charge transfer from H2 to 3 involves the σ bonding orbital of H2 (donor) and an empty 3p orbital of Al (acceptor), both observed in the transition states for Al−O and Al−C bond hydrogenolysis. The reverse charge transfer from 3 to H2 involves the σ* antibonding orbital of H2 (acceptor); however, the donor orbital is different for the two 692
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ACS Catalysis transition states. In TS2, the Al−C σ orbital acts as the electron donor (σ-bond metathesis), while in the case of TS1, an oxygen nonbonding p orbital is the donor (direct hydrogenolysis of the Al−O bond). An additional charge-transfer stabilization mechanism is also observed in TS1 involving a filled nonbonding 2p orbital of O donating charge to the empty 3p orbital on Al. This explains the more facile H2 activation over an Al−O bond. By contrast, this additional stabilization is missing in TS2 since the Al-bound carbon center does not have a nonbonding electron pair. Additionally, DFT calculations also suggest that the energy barrier for H2 scission over an Al−O bond in the dialuminum species 3b is lower by ∼15 kcal/mol compared with the monoaluminum sites 3a (SI, Figures S24 and S25). At this point, it is still unclear whether the dinuclear Al moieties in 3 significantly contribute to the observed higher reactivity. In summary, well-defined CatPOP-supported organoaluminum precatalysts were synthesized and rigorously characterized. The hydrogenation activity displayed by the Al(III) sites in 2 and 3 is rare in the area of organoaluminum catalysis, validating the effectiveness of the catalyst design strategy: isolated, monomeric, and coordinatively unsaturated organoaluminum sites that are not easily formed in solution can mediate organic transformations that are unprecedented compared with their dimeric congeners. More rigorous mechanistic studies are currently underway to gain insights into the mechanism of hydrogenation and the nature of the active hydrogenation species.
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ANL. High-energy X-ray scattering data suitable for PDF analyses were collected at beamline 11-ID-B at the Advanced Photon Source (APS) at ANL. APS is a U.S. DOE User Facility operated for the DOE Office of Science by ANL under Contract DE-AC02-06CH11357. We also thank Dr. Javier Bareño for the assistance with the air-sensitive XPS experiments.
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(1) (a) Bartholomew, C. H.; Farrauto, R. J. Fundamentals of Industrial Catalytic Processes; John Wiley & Sons: Hoboken, NJ, 2011. (b) Ford, M. E. Catalysis of Organic Reactions; CRC Press: Boca Raton, FL, 2000. (c) Johnstone, R. A. W.; Wilby, A. H.; Entwistle, I. D. Chem. Rev. 1985, 85, 129−170. (d) Halpern, J. Inorg. Chim. Acta 1981, 50, 11−19. (e) Copéret, C.; Comas-Vives, A.; Conley, M. P.; Estes, D. P.; Fedorov, A.; Mougel, V.; Nagae, H.; Nuńez-Zarur, F.; Zhizhko, P. A. Chem. Rev. 2016, 116, 323−421. (2) (a) Dyson, P. J. Appl. Organomet. Chem. 2002, 16, 495−500. (b) Camacho-Bunquin, J.; Ferguson, M. J.; Stryker, J. M. J. Am. Chem. Soc. 2013, 135, 5537−5540. (c) Chirik, P. J. Acc. Chem. Res. 2015, 48, 1687−1695. (3) (a) Clapham, S. E.; Hadzovic, A.; Morris, R. H. Coord. Chem. Rev. 2004, 248, 2201−2237. Baiker, A. Chem. Soc. Rev. 2015, 44, 7449− 7464. (4) (a) Stephan, D. W. Acc. Chem. Res. 2015, 48, 306−316. (b) Stephan, D. W.; Erker, G. Angew. Chem., Int. Ed. 2015, 54, 6400− 6441. (5) (a) Chernichenko, K.; Madarász, Á .; Pápai, I.; Nieger, M.; Leskelä, M.; Repo, T. Nat. Chem. 2013, 5, 718−723. (b) Reddy, J. S.; Xu, B.-H.; Mahdi, T.; Fröhlich, R.; Kehr, G.; Stephan, D. W.; Erker, G. Organometallics 2012, 31, 5638−5649. (6) (a) Ghattas, G.; Chen, D.; Pan, F.; Klankermayer, J. Dalton Trans. 2012, 41, 9026. (b) Chen, D.; Wang, Y.; Klankermayer, J. Angew. Chem., Int. Ed. 2010, 49, 9475−9478. (c) Spies, P.; Schwendemann, S.; Lange, S.; Kehr, G.; Fröhlich, R.; Erker, G. Angew. Chem., Int. Ed. 2008, 47, 7543−7546. (d) Xu, B.-H.; Kehr, G.; Fröhlich, R.; Wibbeling, B.; Schirmer, B.; Grimme, S.; Erker, G. Angew. Chem., Int. Ed. 2011, 50, 7183−7186. (7) Wang, Y.; Chen, W.; Lu, Z.; Li, Z. H.; Wang, H. Angew. Chem., Int. Ed. 2013, 52, 7496−7499. (8) (a) Jezl, J. L.; Stuart, A. P. Hydrogenation of Olefins. U.S. Patent 2,983,770, 1960. (b) Hatnean, J. A.; Thomson, J. W.; Chase, P. A.; Stephan, D. W. Chem. Commun. 2014, 50, 301−303. (9) (a) Deno, K. C.; Peterson, H. J.; Saines, G. S. Chem. Rev. 1960, 60, 7−14. (b) Dobereiner, G. E.; Crabtree, R. H. Chem. Rev. 2010, 110, 681−703. (c) Wang, D.; Astruc, D. Chem. Rev. 2015, 115, 6621− 6686. (10) (a) Camacho-Bunquin, J.; Siladke, N. A.; Zhang, G.; Niklas, J.; Poluektov, O. G.; Nguyen, S. T.; Miller, J. T.; Hock, A. S. Organometallics 2015, 34, 947−952. (b) Tanabe, K. K.; Ferrandon, M. S.; Siladke, N. A.; Kraft, S. J.; Zhang, G.; Niklas, J.; Poluektov, O. G.; Lopykinski, S. J.; Bunel, E. E.; Krause, T. R.; Miller, J. T.; Hock, A. S.; Nguyen, S. T. Angew. Chem., Int. Ed. 2014, 53, 12055−12058. (11) Camacho-Bunquin, J.; Shou, H.; Aich, P.; Beaulieu, D. R.; Klotzsch, H.; Bachman, S.; Marshall, C. L.; Hock, A. S.; Stair, P. C. Rev. Sci. Instrum. 2015, 86, 084103. (12) Pelletier, J.; Espinas, J.; Vu, N.; Norsic, S.; Baudouin, A.; Delevoye, L.; Trébosc, J.; Le Roux, E.; Santini, C.; Basset, J.-M.; Gauvin, R. M.; Taoufik, M. Chem. Commun. 2011, 47, 2979−2981. (13) (a) Kermagoret, A.; Kerber, R. N.; Conley, M. P.; Callens, E.; Florian, P.; Massiot, D.; Copéret, C.; Delbecq, F.; Rozanska, X.; Sautet, P. Dalton Trans. 2013, 42, 12681−12687. (b) Li, J.; DiVerdi, J. A.; Maciel, G. E. J. Am. Chem. Soc. 2006, 128, 17093−17101. (14) Wischert, R.; Laurent, P.; Copéret, C.; Delbecq, F.; Sautet, P. J. Am. Chem. Soc. 2012, 134, 14430−14449. (15) Hindin, S. G.; Weller, S. W. J. Phys. Chem. 1956, 60, 1501− 1506.
ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acscatal.6b02771. Details of the catalyst synthesis, characterization, and reactivity studies (PDF)
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REFERENCES
AUTHOR INFORMATION
Corresponding Authors
*E-mail:
[email protected]. *E-mail:
[email protected]. ORCID
Jeffrey Camacho-Bunquin: 0000-0003-2297-3404 Adam S. Hock: 0000-0003-1440-1473 SonBinh T. Nguyen: 0000-0002-6977-3445 Christopher L. Marshall: 0000-0002-1285-7648 Massimiliano Delferro: 0000-0002-4443-165X Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This work was supported by the U.S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, under Contract DEAC02-06CH11357. A.E.P-.P. acknowledges a Beatriu de Pinós Fellowship (BP-DGR 2014) from the Catalan Agency for Administration of University and Research (AGAUR). Theoretical calculations were performed using the computational resources at the Argonne National Laboratory (ANL) Center for Nanoscale Materials and resources provided on Fusion and Blues, two high-performance computing clusters operated by the Laboratory Computing Resource Center at 693
DOI: 10.1021/acscatal.6b02771 ACS Catal. 2017, 7, 689−694
Research Article
ACS Catalysis (16) Ghuman, K. K.; Hoch, L. B.; Szymanski, P.; Loh, J. Y. Y.; Kherani, N. P.; El-Sayed, M. A.; Ozin, G. A.; Singh, C. V. J. Am. Chem. Soc. 2016, 138, 1206−1214. (17) (a) Totten, R. K.; Weston, M. H.; Park, J. K.; Farha, O. K.; Hupp, J. T.; Nguyen, S. T. ACS Catal. 2013, 3, 1454−1459. (b) Weston, M. H.; Farha, O. K.; Hauser, B. G.; Hupp, J. T.; Nguyen, S. T. Chem. Mater. 2012, 24, 1292−1296. (18) (a) Kvisle, S.; Rytter, E. Spectrochim. Acta Part A 1984, 40, 939. (b) Yates, D.; Dembinski, G. W.; Kroll, W. R.; Elliott, J. J. J. Phys. Chem. 1969, 73, 911−921. (19) (a) van Bokhoven, J. A.; Van der Eerden, A.; Koningsberger, D. C. J. Am. Chem. Soc. 2003, 125, 7435−7442. (b) Deng, F.; Du, Y.; Ye, C.; Wang, J.; Ding, T.; Li, H. J. Phys. Chem. 1995, 99, 15208−15214. (20) Cao, L. L.; Daley, E.; Johnstone, T. C.; Stephan, D. W. Chem. Commun. 2016, 52, 5305−5307. (21) Boudier, A.; Breuil, P. R.; Magna, L.; Olivier-Bourbigou, H.; Braunstein, P. Dalton Trans. 2015, 44, 12995−12998. (22) (a) Nandi, P.; Solovyov, A.; Okrut, A.; Katz, A. ACS Catal. 2014, 4, 2492−2495. (b) Nandi, P.; Tang, W.; Okrut, A.; Kong, X.; Hwang, S.-J.; Neurock, M.; Katz, A. Proc. Natl. Acad. Sci. U. S. A. 2013, 110, 2484−2489. (23) Mazoyer, E.; Trebosc, J.; Baudouin, A.; Boyron, O.; Pelletier, J.; Basset, J.-M.; Vitorino, M. J.; Nicholas, C. P.; Gauvin, R. M.; Taoufik, M.; Delevoye, L. Angew. Chem., Int. Ed. 2010, 49, 9854−9858. (24) (a) Hu, B.; Schweitzer, N. M.; Zhang, G.; Kraft, S. J.; Childers, D. J.; Lanci, M. P.; Miller, J. T.; Hock, A. S. ACS Catal. 2015, 5, 3494− 3503. (b) Hu, B.; Getsoian, A.; Schweitzer, N. M.; Das, U.; Kim, H.; Niklas, J.; Poluektov, O.; Curtiss, L. A.; Stair, P. C.; Miller, J. T.; Hock, A. S. J. Catal. 2015, 322, 24−37. (c) Estes, D. P.; Siddiqi, G.; Allouche, F.; Kovtunov, K. V.; Safonova, O. V.; Trigub, A. L.; Koptyug, I. V.; Copéret, C. J. Am. Chem. Soc. 2016, 138, 14987−14997. (d) Delley, M. F.; Silaghi, M.-C.; Nuñez-Zarur, F.; Kovtunov, K. V.; Salnikov, O. G.; Estes, D. P.; Koptyug, I. V.; Comas-Vives, A.; Copéret, C. Organometallics 2016, DOI: 10.1021/acs.organomet.6b00744. (25) (a) Schweitzer, N. M.; Hu, B.; Das, U.; Kim, H.; Greeley, J.; Curtiss, L. A.; Stair, P. C.; Miller, J. T.; Hock, A. S. ACS Catal. 2014, 4, 1091−1098. (b) Getsoian, A.; Das, U.; Camacho-Bunquin, J.; Zhang, G.; Gallagher, J. R.; Hu, B.; Cheah, S.; Schaidle, J. A.; Ruddy, D. A.; Hensley, J. E.; Krause, T. R.; Curtiss, L. A.; Miller, J. T.; Hock, A. S. Catal. Sci. Technol. 2016, 6, 6339−6353.
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DOI: 10.1021/acscatal.6b02771 ACS Catal. 2017, 7, 689−694
