In situ and real-time monitoring of mechanochemical milling reactions using synchrotron X-ray diffraction

Journal name:
Nature Protocols
Volume:
8,
Pages:
1718–1729
Year published:
DOI:
doi:10.1038/nprot.2013.100
Published online

Abstract

We describe the only currently available protocol for in situ, real-time monitoring of mechanochemical reactions and intermediates by X-ray powder diffraction. Although mechanochemical reactions (inducing transformations by mechanical forces such as grinding and milling) are normally performed in commercially available milling assemblies, such equipment does not permit direct reaction monitoring. We now describe the design and in-house modification of milling equipment that allows the reaction jars of the operating mill to be placed in the path of a high-energy (∼90 keV) synchrotron X-ray beam while the reaction is taking place. Resulting data are analyzed using conventional software, such as TOPAS. Reaction intermediates and products are identified using the Cambridge Structural Database or Inorganic Crystal Structure Database. Reactions are analyzed by fitting the time-resolved diffractograms using structureless Pawley refinement for crystalline phases that are not fully structurally characterized (such as porous frameworks with disordered guests), or the Rietveld method for solids with fully determined crystal structures (metal oxides, coordination polymers).

At a glance

Figures

  1. Milling equipment for in situ X-ray diffraction measurements.
    Figure 1: Milling equipment for in situ X-ray diffraction measurements.

    (a) An assembled 14-ml PMMA jar, as used in the experiments described herein. (b) Milling jars of different sizes made from steel, aluminum or PMMA. The milling media are steel balls. (c,d) Side view (c) and front view (d) of the modified Retsch MM200 mill with the milling stations lifted above the mill to allow for the X-ray beam to pass above the mill and through the jars.

  2. Chemical reaction and experimental setup.
    Figure 2: Chemical reaction and experimental setup.

    (a) Scheme of the general reaction for the mechanochemical (LAG or ILAG) conversion of zinc oxide into porous ZIFs. (b) Fragment of the crystal structure for the ZIF-8 product based on zinc(II) and 2-methylimidazolate ions. (c) Positioning of the modified Retsch MM200 mill on a motorized stand, movable in the x-, y- (horizontal) and z-directions (vertical).

  3. Experiment preparation.
    Figure 3: Experiment preparation.

    (a) Proper handling of the two halves of the PMMA milling jar before snapping them together. (b) The milling jar after snapping the two halves together. The left side contains the milling liquid and milling balls. The right side contains the reactants (white powder). (c) Horizontal positioning of the PMMA milling jar on the milling station. (d) The positioning of the milling jar with respect to the X-ray beam is verified using a theodolite.

  4. Outside control of mill operation.
    Figure 4: Outside control of mill operation.

    View of the improvised robotic 'finger' for remote switching on and switching off of the modified Retsch MM200 mill. The control is achieved by having the finger press the 'START' or 'STOP' buttons on the horizontal mill control board.

  5. Data processing.
    Figure 5: Data processing.

    Screenshots of Fit2d after opening the data file and at the end of integration data input, with the values for the experimental setup as previously determined from a calibration procedure involving a standard sample.

  6. Data presentation and quantitative analysis.
    Figure 6: Data presentation and quantitative analysis.

    (a) Example of a time-resolved PXRD pattern (diffractogram) for the LAG synthesis of ZIF-8. The simulated powder diffraction pattern of the product is displayed on top. (b) Combined Pawley and Rietveld refinement for reaction a after 9 min and 40 s. The blue tick marks designate calculated positions of reflections for the product. Blue, observed pattern; red, calculated pattern/background; gray, difference pattern. The contribution of ZnO (blue) is inserted below the experimental pattern. Selected reflections of the product, as well as steel from the milling balls, are highlighted.

  7. Qualitative identification of products using Mercury.
    Figure 7: Qualitative identification of products using Mercury.

    (a,b) Screenshots of simulating the PXRD pattern for a known crystal structure (a) and of changing the wavelength for the simulated diffraction pattern (b).

References

  1. James, S.L. et al. Mechanochemistry: opportunities for new and cleaner synthesis. Chem. Soc. Rev. 41, 413447 (2012).
  2. Takacs, L. The historical development of mechanochemistry. Chem. Soc. Rev. http://dx.doi.org/10.1039/C2CS35442J (7 February 2013).
  3. Ling, A.R. & Baker, J.L. Halogen derivatives of quinone. Part III. Derivatives of quinhydrone. J. Chem. Soc. 63, 13141327 (1893).
  4. Wiggins, K.M., Brantely, J.N. & Bielawski, C.W. Methods for activating and characterizing mechanically responsive polymers. Chem. Soc. Rev. http://dx.doi.org/10.1039/C3CS35493H (7 February 2013).
  5. Beyer, M.K. & Clausen-Schaumann, H. Mechanochemistry: the mechanical activation of covalent bonds. Chem. Rev. 105, 29212948 (2005).
  6. Stolle, A., Szuppa, T., Leonhardt, S.E.S. & Ondruschka, B. Ball milling in organic synthesis: solutions and challenges. Chem. Soc. Rev. 40, 23172329 (2011).
  7. Belcher, W.J., Longstaff, C.A., Neckening, M.R. & Steed, J.W. Channel-containing 1D coordination polymers based on a linear dimetallic spacer. Chem. Commun. 2002, 16021603 (2002).
  8. Lazuen Garay, A., Pichon, A. & James, S.L. Solvent-free synthesis of metal complexes. Chem. Soc. Rev. 36, 846855 (2007).
  9. Rodríguez, B., Bruckmann, A., Rantanen, T. & Bolm, C. Solvent-free carbon-carbon bond formations in ball mills. Adv. Synth. Catal. 349, 22132233 (2007).
  10. Belenguer, A.M., Friščić, T., Day, G.M. & Sanders, J.K.M. Solid-state dynamic combinatorial chemistry: reversibility and thermodynamic product selection in covalent mechanosynthesis. Chem. Sci. 3, 696700 (2011).
  11. Užarević, K. et al. Dynamic molecular recognition in solid state for separating mixtures of isomeric dicarboxylic acids. Angew. Chem. Int. Ed. 52, 55045508 (2013).
  12. Urakaev, F.Kh. & Boldyrev, V.V. Mechanism and kinetics of mechanochemical processes in comminuting devices 2. Applications of the theory. Experiment. Powder Technol. 107, 197206 (2000).
  13. Takacs, L. Self-sustaining reactions induced by ball milling. Prog. Mater. Sci. 47, 355414 (2002).
  14. Friščić, T. et al. Real-time and in situ monitoring of mechanochemical milling reactions. Nat. Chem. 5, 6673 (2013).
  15. Burmeister, C.F. & Kwade, A. Process engineering with planetary ball mills. Chem. Soc. Rev. http://dx.doi.org/10.1039/C3CS35455E (7 February 2013).
  16. Friščić, T., Halasz, I., Štrukil, V., Eckert-Maksić, M. & Dinnebier, R.E. Clean and efficient synthesis using mechanochemistry: coordination polymers, metal-organic frameworks and metallodrugs. Croat. Chem. Acta 85, 367378 (2012).
  17. Friščić, T. Supramolecular concepts and new techniques in mechanochemistry: cocrystals, cages, rotaxanes, open metal-organic frameworks. Chem. Soc. Rev. 41, 34933510 (2012).
  18. Friščić, T. & Jones, W. Recent advances in understanding the mechanism of cocrystal formation via grinding. Cryst. Growth Des. 9, 16211637 (2009).
  19. Bowmaker, G.A. Solvent-assisted mechanochemistry. Chem. Commun. 49, 334348 (2013).
  20. Braga, D. et al. Mechanochemical preparation of molecular and supramolecular organometallic materials and coordination networks. Dalton Trans. 12491263 (2006).
  21. Friščić, T. et al. Ion- and liquid-assisted grinding: improved mechanochemical synthesis of metal-organic frameworks reveals salt inclusion and anion templating. Angew. Chem. Int. Ed. 49, 712715 (2010).
  22. Kuroda, R., Yoshida, J., Nakamura, A. & Nishikiori, S.-i. Annealing assisted mechanochemical syntheses of transition-metal coordination compounds and co-crystal formation. CrystEngComm 11, 427432 (2009).
  23. Hsueh, S.-Y., Cheng, K.-W., Lai, C.-C. & Chiu, S.-H. Efficient solvent-free syntheses of [2]- and [4]Rotaxanes. Angew. Chem. Int. Ed. 47, 44364439 (2007).
  24. Friščić, T. New opportunities for materials synthesis using mechanochemistry. J. Mat. Chem. 20, 75997605 (2010).
  25. Trask, A.V., Motherwell, W.D.S. & Jones, W. Solvent-drop grinding: green polymorph control of cocrystallisation. Chem. Commun. 890891 (2004).
  26. Friščić, T., Childs, S.L., Rizvi, S.A.A. & Jones, W. The role of solvent in mechanochemical and sonochemical cocrystal formation: a solubility-based approach for predicting cocrystallisation outcome. CrystEngComm 11, 418426 (2009).
  27. Beldon, P.J. et al. Rapid room-temperature synthesis of zeolitic imidazolate frameworks by using mechanochemistry. Angew. Chem. Int. Ed. 49, 96409643 (2010).
  28. Zhang, J.-P., Zhang, Y.-B., Lin, J.-B. & Chen, X.-M. Metal azolate frameworks: from crystal engineering to functional materials. Chem. Rev. 112, 10011033 (2012).
  29. Šepelák, V., Bégin-Colin, S. & Le Caër, G. Transformations in oxides induced by high-energy ball-milling. Dalton Trans. 41, 1192711948 (2012).
  30. Ravnsbæk, D.B., Sørensen, L.H., Filinchuk, Y., Besenbacher, F. & Jensen, T.R. Screening of metal borohydrides by mechanochemistry and diffraction. Angew. Chem. Int. Ed. 51, 35823586 (2012).
  31. Biswal, B.P. et al. Mechanochemical synthesis of chemically stable isoreticular covalent organic frameworks. J. Am. Chem. Soc. 135, 53285331 (2013).
  32. Içli, B. et al. Synthesis of molecular nanostructures by multicomponent condensation reactions in a ball mill. J. Am. Chem. Soc. 131, 31543155 (2009).
  33. Cliffe, M.J., Mottilo, C., Stein, R.S., Bučar, D.-K. & Friščić, T. Accelerated aging: a low energy, solvent-free alternative to solvothermal and mechanochemical synthesis of metal–organic frameworks. Chem. Sci. 3, 24952500 (2012).

Download references

Author information

Affiliations

  1. Division of Materials Chemistry, Ruđer Bošković Institute, Zagreb, Croatia.

    • Ivan Halasz
  2. Structure of Materials Group, European Synchrotron Radiation Facility, Grenoble, France.

    • Simon A J Kimber &
    • Veijo Honkimäki
  3. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK.

    • Patrick J Beldon
  4. Department of Chemistry, University of Cambridge, Cambridge, UK.

    • Ana M Belenguer,
    • Richard C Nightingale &
    • Tomislav Friščić
  5. Max Planck-Institute for Solid State Research, Stuttgart, Germany.

    • Frank Adams &
    • Robert E Dinnebier
  6. Department of Chemistry and Centre for Green Chemistry and Catalysis, McGill University, Montreal, Quebec, Canada.

    • Tomislav Friščić

Contributions

The manuscript was composed and research was performed by I.H., S.A.J.K., P.J.B., A.M.B., F.A., V.H. and T.F. Detailed designs for mill modification were provided by R.C.N. Research was organized by T.F., I.H. and R.E.D. Manuscript preparation and submission were organized by T.F.

Competing financial interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to:

Author details

Supplementary information

PDF files

  1. Supplementary Manual (526 KB)

    Technical drawings of the mill extension and milling jar.

Additional data