Abstract
Generating parahydrogen-induced polarization (PHIP) of nuclear spins with immobilized transition metal complexes as hydrogenation catalysts allows one to produce pure hyperpolarized substances, which can open new revolutionary perspectives for PHIP applications. A major drawback of immobilized complexes is their low stability under reaction conditions. In the present work we studied an immobilized iridium complex, Ir/SiO2P, synthesized by a covalent anchoring of Vaska’s complex on phospine-modified silica gel. This complex was used to obtain hyperpolarized gasses in the gas phase hydrogenation of propene, propyne and 1-butyne with parahydrogen in PASADENA and ALTADENA experiments. It was found that, in contrast to other immobilized complexes, Ir/SiO2P is stable under reaction conditions at up to 140°C, and the reduction of iridium does not occur according to XPS analysis. Moreover, the application of Ir/SiO2P catalyst allowed us to generate continuous flow of hyperpolarized propene and 1-butene with (300–500)-fold NMR signal enhancement which is significantly higher than commonly observed for most supported metal catalysts. The shape of polarized propene signals in PASADENA experiment has indicated that parahydrogen addition to propyne occurs non-stereospecifically, i.e. PHIP was observed for all protons of the vinyl fragment of propene. The analysis of the polarized signals has shown that syn pairwise addition dominates, which was confirmed by spectra simulations. It was found that storage of Ir/SiO2P under Ar atmosphere leads to a decrease in PHIP amplitude and an increase in the activity of the catalyst. This observation is discussed in terms of the interaction of Ir/SiO2P with trace amounts of oxygen in Ar, leading to partial oxidation of triphenylphosphine ligand to triphenylphosphine oxide accompanied by the activation of the immobilized complex. It was also found that the interaction of Ir/SiO2P with alkenes likely leads to formation of stable monohydride complexes, decreasing the production of PHIP in hydrogenations. At the same time, stable substrate complexes are likely formed in alkyne hydrogenations, leading to a significant decrease in the monohydride complex formation and to an increased production of PHIP.
Dedicated to: Kev Salikhov on the occasion of his 80th birthday.
Funding source: Russian Science Foundation
Award Identifier / Grant number: 14-35-00020
Funding statement: This work was financially supported by the Russian Science Foundation (project # 14-35-00020).
Acknowledgments
This work was financially supported by the Russian Science Foundation (project # 14-35-00020).
References
1. C. R. Bowers, in “Encyclopedia of Nuclear Magnetic Resonance”, volume 9, (Eds. D. M. Grant and R. K. Harris), John Wiley & Songs, Ltd, Chichester (2002), p. 750.Search in Google Scholar
2. S. B. Duckett, R. E. Mewis, Acc. Chem. Res. 45 (2012) 1247.10.1021/ar2003094Search in Google Scholar
3. H. E. Moller, X. J. Chen, B. Saam, K. D. Hagspiel, G. A. Johnson, T. A. Altes, E. E. de Lange, H. U. Kauczor, Magn. Reson. Med. 47 (2002) 1029.10.1002/mrm.10173Search in Google Scholar
4. J. H. Ardenkjaer-Larsen, J. Magn. Reson. 264 (2016) 3.10.1016/j.jmr.2016.01.015Search in Google Scholar
5. C. R. Bowers, D. P. Weitekamp, Phys. Rev. Lett. 57 (1986) 2645.10.1103/PhysRevLett.57.2645Search in Google Scholar
6. C. R. Bowers, D. P. Weitekamp, J. Am. Chem. Soc. 109 (1987) 5541.10.1021/ja00252a049Search in Google Scholar
7. S. B. Duckett, N. J. Wood, Cord. Chem. Rev. 252 (2008) 2278.10.1016/j.ccr.2008.01.028Search in Google Scholar
8. J. Natterer, J. Bargon, Prog. Nucl. Magn. Res. 31 (1997) 293.10.1016/S0079-6565(97)00007-1Search in Google Scholar
9. K. V. Kovtunov, V. V. Zhivonitko, I.V. Skovpin, D. A. Barskiy, O. G. Salnicov, I. V. Koptyug, J. Phys. Chem. C 117 (2013) 22887.10.1021/jp407348rSearch in Google Scholar
10. R. Eisenberg, T. Eisenschmid, M. Chinn, R. Kirss, in “Homogeneous Transition Metal Catalyzed Reaction” volume 240, (Ed. W. R. Moser, D. W. Slocum) American Chemical Society, Washington, DC (1992), pp. 47–74.10.1021/ba-1992-0230.ch004Search in Google Scholar
11. S. B. Duckett, C. J. Sleigh, Prog. Nucl. Magn. Reson. Spectrosc. 34 (1999) 71.10.1016/S0079-6565(98)00027-2Search in Google Scholar
12. V. V. Zhivonitko, V.-V. Telkki, K. Chernichenko, T. Repo, M. Leskelä, V. Sumerin, I. V. Koptyug, J. Am. Chem. Soc. 136 (2014) 598.10.1021/ja410396gSearch in Google Scholar PubMed
13. K. V. Kovtunov, I. E. Beck, V. I. Bukhtiyarov, I. V. Koptyug, Angew. Chem. Int. Ed. 47 (2008) 1492.10.1002/anie.200704881Search in Google Scholar PubMed
14. K. V. Kovtunov, V. V. Zhivonitko, I. V. Skovpin, D. A. Barskiy, I. V. Kotyug, Top. Curr. Chem. 338 (2013) 123.10.1007/128_2012_371Search in Google Scholar PubMed
15. V. V. Zhivonitko, K. V. Kovtunov, I. V. Skovpin, D. A. Barskiy, O. G. Salnikov, I. V. Kotyug, Understanding Organometallic Reaction Mechanisms and Catalysis; Computational and Experimental Tools, Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany (2014), p. 145.Search in Google Scholar
16. R. Zhou, W. Cheng, L. M. Neal, E. W. Zhao, K. Ludden, H. E. Hagelin-Weaver, C. R. Bowers, Phys. Chem. Chem. Phys. 17 (2015) 26121.10.1039/C5CP04223BSearch in Google Scholar
17. V. V. Zhivonitko, I. V. Skovpin, M. Crespo-Quesada, L. Kiwi-Minsker, I. V. Kotyug, J. Phys. Chem. C 120 (2016) 4945.10.1021/acs.jpcc.5b12391Search in Google Scholar
18. K. V. Kovtunov, D. A. Barskiy, O. G. Salnikov, A. K. Khudorozhkov, V. I. Bukhtiyarov, I. P. Prosvirin, I. V. Kotyug, Chem. Commun. 50 (2014) 875.10.1039/C3CC44939DSearch in Google Scholar PubMed
19. T. Gutmann, T. Ratajczyk, Y. Xu, H. Breitzke, A. Grunberg, S. Dillenberger, U. Bommerich, T. Trantzschel, J. Bernarding, G. Buntkowsky, Solid State NMR. 38 (2011) 90.10.1016/j.ssnmr.2011.03.001Search in Google Scholar PubMed
20. A. M. Balu, S. B. Duckett, R. Luque, Dalton Trans. 26 (2009) 5074.10.1039/b906449dSearch in Google Scholar PubMed
21. S. Abdulhussain, H. Breitzke, T. Ratajczyk, A. Grunberg, M. Srour, D. Arnaut, H. Weidler, U. Kunz, H. J. Kleebe, U. Bommerich, J. Bernarding, T. Gutmann, G. Buntkowsky, Chem. Eur. J. 20 (2014) 1159.10.1002/chem.201303020Search in Google Scholar PubMed
22. V.-V. Telkki, V. V. Zhivonitko, S. Ahola, K. V. Kovtunov, J. Jokisaari, I. V. Koptyug, Angew. Chem. Int. Ed. 49 (2010) 8363.10.1002/anie.201002685Search in Google Scholar PubMed
23. V. V. Zhivonitko, V.-V. Telkki, I. V. Koptyug, Angew. Chem. Int. Ed. 51 (2012) 8054.10.1002/anie.201202967Search in Google Scholar
24. V. V. Zhivonitko, K. V. Kovtunov, I. E. Beck, A. B. Ayupov, V. I. Bukhtiyarov, I. V. Koptyug, J. Phys. Chem. C 115 (2011) 13386.10.1021/jp203398jSearch in Google Scholar
25. M. Tada, Y. Iwasawa, Chem. Commun. (2006) 2833.10.1039/b601507gSearch in Google Scholar
26. I. V. Koptyug, I. V. Koptyug, S. R. Burt, M. S. Anwar, C. Hilty, S. I. Han, A. Pines, R. Z. Sagdeev, J. Am. Chem. Soc. 129 (2007) 5580.10.1021/ja068653oSearch in Google Scholar
27. I. V. Skovpin, V.V. Zhivonitko, I. V. Koptyug, Appl. Magn. Reson. 41 (2011) 393.10.1007/s00723-011-0255-zSearch in Google Scholar
28. I. V. Skovpin, V. V. Zhivonitko, R. Kaptein, I. V. Koptyug, Appl. Magn. Reson. 44 (2013) 289.10.1007/s00723-012-0419-5Search in Google Scholar
29. J. Blumel, Coord. Chem. Rev. 252 (2008) 2410.10.1016/j.ccr.2008.06.013Search in Google Scholar
30. W. Strohmeier, J. Organometal. Chem. 32 (1971) 137.10.1016/S0022-328X(00)80168-0Search in Google Scholar
31. W. Strohmeier, R. Fleischmann, T. Onoda, J. Organometal. Chem. 28 (1971) 281.10.1016/S0022-328X(00)84577-5Search in Google Scholar
32. C. Mastes, Homogeneous Transition-metal Catalysis: A Gentle Art, Springer, Netherlands (1981), p. 38.Search in Google Scholar
33. F. Holsboer, W. Beck, H. D. Bartunik, J. Chem. Soc. Dalt. Trans. 17 (1973) 1828.10.1039/DT9730001828Search in Google Scholar
34. R. Zanoni, R. Psaro, C. Dossi, L. Garlaschelli, R. Pergola, D. Roberto, J. Clust. Sci. 1 (1990) 241.10.1007/BF00702743Search in Google Scholar
35. M. P. Lanci, D. W. Brinkley, K. L. Stone, V. V. Smirnov, J. P. Roth, Angew. Chem. Int. Ed. Engl. 44 (2005) 7273.10.1002/anie.200502096Search in Google Scholar PubMed
36. K. D. Schramm, T. H. Tulip, J. A. Ibers, Inorg. Chem. 19 (1980) 3183.10.1021/ic50212a074Search in Google Scholar
37. P. B. Chock, J. Halpern, J. Am. Chem. Soc. 88 (1966) 3511.10.1021/ja00967a009Search in Google Scholar
38. L. Vaska, Science 140 (1963) 809.10.1126/science.140.3568.809Search in Google Scholar PubMed
39. L. Vaska, Acc. Chem. Res. 1 (1968) 335.10.1021/ar50011a003Search in Google Scholar
40. B.R. James, N. A. Memon, Can. J. Chem. 46 (1968) 217.10.1139/v68-034Search in Google Scholar
41. F. van Rantwijk, Th. G. Speek, H. van Bekkum, Rec. Trav. Chim. 91 (1972) 1057.10.1002/recl.19720910905Search in Google Scholar
42. L. Vaska, J. Am. Chem. Soc. 88 (1966) 4100.10.1021/ja00969a043Search in Google Scholar PubMed
43. J. S. Valentine, J. Chem. Commun. (1973) 857.10.1039/c39730000857Search in Google Scholar
44. M. A. Bennett, D. L. Milner, J. Am. Chem. Soc. 91 (1969) 6983.10.1021/ja01053a016Search in Google Scholar
45. M. A. Bennett, D. L. Milner, Chem. Commun. (1967) 581.10.1039/c19670000581Search in Google Scholar
Supplemental Material:
The online version of this article (DOI: 10.1515/zpch-2016-0824) offers supplementary material, available to authorized users.
©2017 Walter de Gruyter GmbH, Berlin/Boston