Chemistry Beyond the Crystal

Chemistry Beyond the Crystal

Presenter

  • Simon A. J. Kimber, Neutron Sciences Directorate
October 11, 2017 - 10:00am to 11:00am

Abstract 

Molecular structure determines much of what is important in chemistry, yet crystallographers are wedded to the solid state rather than the solution phase. In this presentation, I will show how we can think in terms of “chemistry beyond the crystal” using high-energy x-rays and neutrons.

Many new questions present themselves. For example,

  • The electronic states important for catalysis and optical properties, vibrational modes etc., are determined by molecular point groups. Should we measure the solid-state structure, bound by intermolecular forces, or should we determine the equilibrium solution phase structure? I will show how total scattering allows the refinement of metal cluster structures during UV induced catalytic cycles.
  • Crystallization by evaporation is an intrinsically nonequilibrium process. How often do we miss the true thermodynamic product of a reaction in solution? I will show how a simple hydrolysis reaction produces magic size clusters, with a delicate interplay between solvent and time. Similarly, in situ experiment detect a crossover from amorphous -crystalline ZnO nanoparticles during synthesis.
  • Is a snapshot of molecules and co-crystallized species relevant to reaction rates or to ion association in solution? Can the solutes and solvent structures influence each other? I will show how scattering experiments detect apparently ubiquitous solvent restructuring at the surface of solvated nanoparticles. 

Additional Information 

Refreshments will be served, starting at 9:30 am.

Sponsoring Organization 

Physical Sciences Directorate Materials and Chemistry Seminar Series

Location

  • Weinberg Auditorium
  • Building: 4500-N
  • Room: I-126

Contact Information

Share