Journal of the American Chemical Society
Communication
involving a Zn2+-binding Mn(IV)−oxo complex10 and a Sc3+-
binding [FeIV(O)(N4Py)]2+ complex.17
(3) (a) Rittle, J.; Green, M. T. Science 2010, 330, 933. (b) Abu-Omar,
M. M.; Loaiza, A.; Hontzeas, N. Chem. Rev. 2005, 105, 2227.
(c) Krebs, C.; Fujimori, D. G.; Walsh, C. T.; Bollinger, J. M., Jr. Acc.
Chem. Res. 2007, 40, 484. (d) Bruijnincx, P. C. A.; van Koten, G.; Klein
Gebbink, R. J. M. Chem. Soc. Rev. 2008, 37, 2716.
The contrasting effects of Sc3+ ion binding observed in the
OAT and HAT reactions by Mn(IV)−oxo species might be
explained by the difference in their reaction mechanisms. In the
case of OAT, ET from the thioanisole to 4, which may be the
rate-determining step, is followed by a fast OAT step, as shown
in Sc3+-promoted OAT reactions by [FeIV(O)(N4Py)]2+.9 The
proposed ET pathway is supported by the good linear
correlation between the reaction rate constants and the Eox
values for the para-substituted thioanisoles (Figure S13).9b,18
Such an ET pathway requires only a little interaction between 4
and the thioanisole, which is rather insensitive to the steric
effect caused by the Sc3+ ions bound to the Mn−oxo moiety. In
contrast, the HAT reaction requires significant interaction in
the substrate C−H bond activation by the Mn−oxo moiety in 3
or 4, which would be hindered by the Sc3+ ions bound to the
Mn−oxo moiety (see Figure 1).
(4) (a) Nam, W. Acc. Chem. Res. 2007, 40, 522. (b) Goldberg, D. P.
Acc. Chem. Res. 2007, 40, 626. (c) Aviv, I.; Gross, Z. Chem. Commun.
2007, 1987. (d) Gunay, A.; Theopold, K. H. Chem. Rev. 2010, 110,
1060. (e) Borovik, A. S. Chem. Soc. Rev. 2011, 40, 1870. (f) Mayer, J.
M. Acc. Chem. Res. 2011, 44, 36. (g) de Visser, S. P.; Rohde, J.-U.; Lee,
Y.-M.; Cho, J.; Nam, W. Coord. Chem. Rev. 2013, 257, 381.
(5) (a) Pfaff, F. F.; Kundu, S.; Risch, M.; Pandian, S.; Heims, F.;
Pryjomska-Ray, I.; Haack, P.; Metzinger, R.; Bill, E.; Dau, H.; Comba,
P.; Ray, K. Angew. Chem., Int. Ed. 2011, 50, 1711. (b) Yiu, S.-M.; Man,
W.-L.; Lau, T.-C. J. Am. Chem. Soc. 2008, 130, 10821. (c) Lam, W. W.
Y.; Yiu, S.-M.; Lee, J. M. N.; Yau, S. K. Y.; Kwong, H.-K.; Lau, T.-C.;
Liu, D.; Lin, Z. J. Am. Chem. Soc. 2006, 128, 2851. (d) Yiu, S.-M.; Wu,
Z.-B.; Mak, C.-K.; Lau, T.-C. J. Am. Chem. Soc. 2004, 126, 14921.
(e) Miller, C. G.; Gordon-Wylie, S. W.; Horwitz, C. P.; Strazisar, S. A.;
Peraino, D. K.; Clark, G. R.; Weintraub, S. T.; Collins, T. J. J. Am.
Chem. Soc. 1998, 120, 11540. (f) Du, H.; Lo, P.-K.; Hu, Z.; Liang, H.;
Lau, K.-C.; Wang, Y.-N.; Lam, W. W. Y.; Lau, T.-C. Chem. Commun.
2011, 47, 7143.
(6) (a) Umena, Y.; Kawakami, K.; Shen, J.-R.; Kamiya, N. Nature
2011, 473, 55. (b) Gatt, P.; Patrie, S.; Stranger, R.; Pace, R. J. Angew.
Chem., Int. Ed. 2012, 51, 12025.
(7) (a) Kanady, J. S.; Tsui, E. Y.; Day, M. W.; Agapie, T. Science
2011, 333, 733. (b) Park, Y. J.; Ziller, J. W.; Borovik, A. S. J. Am. Chem.
Soc. 2011, 133, 9258.
(8) Fukuzumi, S.; Morimoto, Y.; Kotani, H.; Naumov, P.; Lee, Y.-M.;
Nam, W. Nat. Chem. 2010, 2, 756.
(9) (a) Morimoto, Y.; Kotani, H.; Park, J.; Lee, Y.-M.; Nam, W.;
Fukuzumi, S. J. Am. Chem. Soc. 2011, 133, 403. (b) Park, J.; Morimoto,
Y.; Lee, Y.-M.; Nam, W.; Fukuzumi, S. J. Am. Chem. Soc. 2011, 133,
5236.
In summary, we have reported the synthesis, characterization,
and reactivity of mononuclear non-heme Mn(IV)−oxo
complexes binding Sc3+ ions and the contrasting effect of the
bound metal ion on the reactivities of the Mn(IV)−oxo species
in OAT and HAT reactions. The increased reactivity in OAT is
rationalized by the involvement of an ET pathway, whereas the
decreased reactivity in HAT is interpreted in terms of the steric
hindrance caused by the Sc3+ ions bound to the Mn−oxo
moiety. The present results provide an example demonstrating
a diverse effects of a redox-inactive metal ion on the reactivities
of high-valent metal−oxo species in oxidation reactions.
ASSOCIATED CONTENT
* Supporting Information
■
S
(10) Leeladee, P.; Baglia, R. A.; Prokop, K. A.; Latifi, R.; de Visser, S.
P.; Goldberg, D. P. J. Am. Chem. Soc. 2012, 134, 10397.
(11) Wu, X.; Seo, M. S.; Davis, K. M.; Lee, Y.-M.; Chen, J.; Cho, K.-
B.; Pushkar, Y. N.; Nam, W. J. Am. Chem. Soc. 2011, 133, 20088.
(12) Evans, D. F.; Jakubovic, D. A. J. Chem. Soc., Dalton Trans. 1988,
2927.
Experimental section, crystal structure of 1-CF3SO3 (CIF),
spectroscopic data for 1−4, reactivity data for 2−4, and DFT
Calculations section. This material is available free of charge via
(13) Cho, K.-B.; Shaik, S.; Nam, W. J. Phys. Chem. Lett. 2012, 3, 2851.
(14) Direct binding of two Sc3+ ions to the Mn−O moiety in 4 may
be unlikely to occur, since the resulting structure is 40 kcal/mol higher
in energy than the one with only one bound Sc3+ (see Figure S15).
(15) Although 3 showed a reactivity between those of 2 and 4 in the
oxidation of thioanisole, we were not able to determine an accurate
rate constant because of poor kinetic fitting in the first-order decay
profile for thioanisole oxidation by 3.
AUTHOR INFORMATION
Corresponding Author
■
Notes
The authors declare no competing financial interest.
(16) (a) Garcia-Bosch, I.; Company, A.; Cady, C. W.; Styring, S.;
Browne, W. R.; Ribas, X.; Costas, M. Angew. Chem., Int. Ed. 2011, 50,
5648. (b) Sawant, S. C.; Wu, X.; Cho, J.; Cho, K.-B.; Kim, S. H.; Seo,
M. S.; Lee, Y.-M.; Kubo, M.; Ogura, T.; Shaik, S.; Nam, W. Angew.
Chem., Int. Ed. 2010, 49, 8190. (c) Jeong, Y. J.; Kang, Y.; Han, A.-R.;
Lee, Y.-M.; Kotani, H.; Fukuzumi, S.; Nam, W. Angew. Chem., Int. Ed.
2008, 47, 7321.
ACKNOWLEDGMENTS
■
The authors gratefully acknowledge research support of this
work by the NRF of Korea through CRI, WCU (R31-2008-
000-10010-0), GRL (2010-00353), Basic Research Program
(2010-0002558) (to M.S.S.) and by a Grant-in-Aid (20108010)
and a Global COE Program from MEXT, Japan (to S.F.). The
research at Purdue was supported by DOE-BES (DE-FG02-
10ER16184 to Y.N.P.) and an NSF Graduate Research
Fellowship (0833366 to K.M.D.). Synchrotron facilities were
provided by the APS at Argonne National Laboratory, operated
by DOE-BES under Contract DE-AC02-06CH11357. We
thank Dr. Steve Heald and Dr. Dale Brewer for help with
experiments at BM-20, APS.
(17) Morimoto, Y.; Park, J.; Suenobu, T.; Lee, Y.-M.; Nam, W.;
Fukuzumi, S. Inorg. Chem. 2012, 51, 10025.
(18) (a) Goto, Y.; Matsui, T.; Ozaki, S.; Watanabe, Y.; Fukuzumi, S. J.
Am. Chem. Soc. 1999, 121, 9497. (b) Taki, M.; Itoh, S.; Fukuzumi, S. J.
Am. Chem. Soc. 2002, 124, 998. (c) Arias, J.; Newlands, C. R.; Abu-
Omar, M. M. Inorg. Chem. 2001, 40, 2185. (d) McPherson, L. D.;
Drees, M.; Khan, S. I.; Strassner, T.; Abu-Omar, M. M. Inorg. Chem.
2004, 43, 4036. (e) Kumar, A.; Goldberg, I.; Botoshansky, M.;
Buchman, Y.; Gross, Z. J. Am. Chem. Soc. 2010, 132, 15233.
REFERENCES
■
(1) Nam, W. Acc. Chem. Res. 2007, 40, 465 and references therein.
(2) Hammarstrom, L.; Hammes-Schiffer, S. Acc. Chem. Res. 2009, 42,
̈
1859 and references therein.
6391
dx.doi.org/10.1021/ja312113p | J. Am. Chem. Soc. 2013, 135, 6388−6391