Molecular self-modification: homolog of a manganese laundry bleach catalyst oxidatively transforms its tetradentate ligand into a novel hexadentate derivative

  • Guochuan Yin
  • Suparna Baksi Roy
  • Andrew M. Danby
  • Victor Day
  • John Carter
  • William M. Scheper
  • Daryle H. Busch
Original Article


On the basis of mass spectral studies alone, the relatively new manganese complex, Mn(Et2EBC)Cl2 (Et2EBC = 4,11-diethyl-1,4,8,11-tetraazabicyclo[6.6.2]hexadecane), a homolog of the well proven, peroxide-based laundry bleach, Mn(Me2EBC)Cl2, has been reported to undergo a sequence of 2-electron oxidation steps, ultimately converting its ethyl groups into chelated ethoxo and methylene carboxylato groups, [MnIV{(OCH2CH2)(O2CCH2)}EBC)](PF6)2. We report here the isolation and characterization of that unusual product, and provide insight into the remarkable catalytic pathway to its formation. At temperatures above 0 °C, oxidation by aqueous H2O2 reliably transforms Mn(Et2EBC)Cl2 into [MnIV{(OCH2CH2)(O2CCH2)}EBC)]2+. The experimental data for this intramolecular ethyl group transformation is consistent with oxygen insertion into a methyl C–H moiety of the ethyl group, –NCH2C(–H)H2, by the MnIV–OOH functional group.


Molecular self-modification Oxidation catalyst Hexadentate ligand Manganese(IV) complex Bleach catalyst Insertion mechanism Cross-bridged macrocycle Inorganic chemistry Transition metal chemistry Manganese chemistry Reaction mechanisms Oxygen atom insertion 



Support by the Procter and Gamble Company is deeply appreciated, and we also thank the National Science Foundation Engineering Research Center Grant (EEC-0310689), at the University of Kansas, for partial support. At KU, MS analyses of the manganese(IV) complex under various conditions were performed under the guidance of R. C. Drake, and the crystal structure was determined by Dr Victor Day.

Supplementary material

10847_2011_9974_MOESM1_ESM.doc (97 kb)
Supplementary material 1 (DOC 97 kb)


  1. 1.
    Yin, G., McCormick, J.M., Buchalova, M., Danby, A.M., Rodgers, K., Smith, K., Perkins, C., Kitko, D., Carter, J., Scheper, W.M., Busch, D.H.: Synthesis, characterization, and solution properties of a novel cross-bridged cyclam manganese(IV) complex having two terminal hydroxo ligands. Inorg Chem 45, 8052–8061 (2006)CrossRefGoogle Scholar
  2. 2.
    Ferreira, K.N., Iverson, T.M., Maghlaoui, K., Barber, J., Iwata, S.: Architecture of the photosynthetic oxygen-evolving center. Science 303, 1831–1838 (2004)CrossRefGoogle Scholar
  3. 3.
    Tommos, C., Babcock, G.T.: Oxygen production in nature: a light-driven metalloradical enzyme process. Acc. Chem. Res. 31, 18–25 (1998)CrossRefGoogle Scholar
  4. 4.
    Vrettos, J.S., Brudvig, G.W.: Oxygen evolution. In: Comprehensive coordination chemistry II. 8, 507–547 (2004)Google Scholar
  5. 5.
    Pecoraro, V.L., Baldwin, M.J., Caudle, M.T., Hsieh, W., Law, N.A.: A proposal for water oxidation in photosystem II. Pure Appl. Chem. 70, 925–929 (1998)CrossRefGoogle Scholar
  6. 6.
    Yin, G., Buchalova, M., Danby, A.M., Perkins, C.M., David Kitko, D., Carter, J., Scheper, W.M., Busch, D.H.: Olefin oxygenation by the hydroperoxide adduct of a nonheme manganese(IV) complex: epoxidations by a metallo-peracid produces gentle selective oxidations. J. Am. Chem. Soc. 127, 17170–17171 (2005)CrossRefGoogle Scholar
  7. 7.
    Yin, G., Buchalova, M., Danby, A.M., Perkins, C.M., David Kitko, D., Carter, J., Scheper, W.M., Busch, D.H.: Olefin epoxidation by the hydrogen peroxide adduct of a novel non-heme mangangese(IV) complex: demonstration of oxygen transfer by multiple mechanisms. Inorg. Chem 45, 3467–3474 (2006)CrossRefGoogle Scholar
  8. 8.
    Yin, G., Danby, A.M., Kitko, D., Carter, J.D., Scheper, W.M., Busch, D.H.: Understanding the selectivity of a moderate oxidation catalyst: hydrogen abstraction by a fully characterized, activated catalyst, the robust dihydroxo manganese(IV) complex of a bridged cyclam. J. Am. Chem. Soc. 129, 1512–1513 (2007)CrossRefGoogle Scholar
  9. 9.
    Busch, D.H.; Collinson, S.R.; Hubin, T.J.; Labeque, R.; Williams, B.K.; Johnston, J.P.; Kitko, D.J.; St. Laurent, J.C.T.R.B.; Perkins, C.M. Bleach compositions containing metal bleach catalyst for detergents. WO 98/39406Google Scholar
  10. 10.
    Busch, D.H.; Collinson, S.R.; Hubin, T.J. Catalysts and methods for catalytic oxidation. WO98/39098, 1998Google Scholar
  11. 11.
    Yin, G.; Danby, A.M.; Day, V.R; Roy, S.B.; Carter, J.; Scheper, W.M.; Busch, D.H.: Similarities and differences in properties and behavior of two H2O2-activated manganese catalysts having structures differing only by methyl and ethyl substituents. J. Coordinat. Chem. 2011, 64(1), 4-17, 40th Anniversary IssueGoogle Scholar
  12. 12.
    Yu-LRan, Liu.: Bond dissociation energies in organic compounds. CRC Press, Boca Raton, FL (2003)Google Scholar
  13. 13.
    Frey, P.A., Hegeman, A.D.: Enzymatic reaction mechanisms. Oxford University Press, New York (2007)Google Scholar
  14. 14.
    Vaz, D.N., McGinnity, D.F., Coon, M.J.: Epoxidation of olefins by cytochrome P450: evidence from site-specific mutagenesis for hydroperoxo-iron as an electrophilic oxidant. Proc. Natl. Acad. Sci. USA 95, 3555–3560 (1998)CrossRefGoogle Scholar
  15. 15.
    Newcomb, M., Aebisher, D., Shen, R., Chandrasena, R.E.P., Hollenberg, P.F., Coon, M.J.: Kinetic isotope effects implicate two electrophilic oxidants in cytochrome P450-catalyzed hydroxylations. J. Am. Chem. Soc. 125, 6064–6065 (2003)CrossRefGoogle Scholar
  16. 16.
    Toy, P.H., Newcomb, M., Coon, M.J., Vaz, A.D.N.: Two distinct electrophilic oxidants effect hydroxylation in cytochrome P-450-catalyzed reactions. J. Am. Chem. Soc. 120, 9718–9719 (1998)CrossRefGoogle Scholar
  17. 17.
    Bach, R.D., Su, M.D., Andres, J.L., Schlegel, H.B.: Structure and reactivity of diamidoiron(III) hydroperoxide. The mechanism of oxygen-atom transfer to ammonia. J. Am. Chem. Soc. 115, 8763–8769 (1993)CrossRefGoogle Scholar
  18. 18.
    Nam, W., Ho, R., Valentine, J.S.: Iron-cyclam complexes as catalysts for the epoxidation of olefins by 30% aqueous hydrogen peroxide in acetonitrile and methanol. J. Am. Chem. Soc. 113, 7052–7054 (1991)CrossRefGoogle Scholar
  19. 19.
    Sam, J.W., Tang, X.J., Peisach, J.: Electrospray mass spectrometry of iron bleomycin: demonstration that activated bleomycin is a ferric peroxide complex. J. Am. Chem. Soc. 116, 5250–5256 (1994)CrossRefGoogle Scholar
  20. 20.
    Ho, R.Y.N., Roelfes, G., Feringa, B.L., Que Jr., L.: Raman evidence for a weakened O−O bond in mononuclear low-spin iron(III)−hydroperoxidesJ. Am. Chem. Soc. 121, 264–265 (1999)CrossRefGoogle Scholar
  21. 21.
    Nam, W., Lim, M.H., Lee, H.J., Kim, C.: Evidence for the participation of two distinct reactive intermediates in iron(III) porphyrin complex-catalyzed epoxidation reactions. J. Am. Chem. Soc. 122, 6641–6647 (2000)CrossRefGoogle Scholar
  22. 22.
    Wadhwani, P., Mukherjee, M., Bandyopadhyay, D.: The prime reactive intermediate in the iron(III) porphyrin complex catalyzed oxidation reactions by tert-butyl hydroperoxide. J. Am. Chem. Soc. 123, 12430–12431 (2001)CrossRefGoogle Scholar
  23. 23.
    Kim, C., Chen, K., Kim, J., Que Jr., L.: Stereospecific alkane hydroxylation with H2O2 catalyzed by an iron(II)−tris(2-pyridylmethyl)amine complex. J. Am. Chem. Soc. 119, 5964–5965 (1997)CrossRefGoogle Scholar
  24. 24.
    Sano, S., Sano, T., Morishima, I., Shiro, Y., Maeda, Y.: On the mechanism of the chemical and enzymic oxygenations of α-oxyprotohemin IX to Fe-biliverdin IXα. Proc. Natl. Acad. Sci. USA 83, 531–535 (1986)CrossRefGoogle Scholar
  25. 25.
    Ortiz de Montellano, P.R.: Heme oxygenase mechanism: evidence for an electrophilic, ferric peroxide species. Acc. Chem. Res. 31, 543–549 (1998)CrossRefGoogle Scholar
  26. 26.
    Avila, L., Huang, H., Damaso, C.O., Lu, S., Moënne-Loccoz, P., Rivera, M.: Coupled oxidation vs. heme oxygenation: insights from axial ligand mutants of mitochondrial cytochrome b5. J. Am. Chem. Soc. 125, 4103 (2003)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Guochuan Yin
    • 1
  • Suparna Baksi Roy
    • 1
  • Andrew M. Danby
    • 1
  • Victor Day
    • 1
  • John Carter
    • 2
  • William M. Scheper
    • 2
  • Daryle H. Busch
    • 1
  1. 1.Department of ChemistryThe University of KansasLawrenceUSA
  2. 2.The Procter and Gamble CompanyCincinnatiUSA

Personalised recommendations