- Simon A. J. Kimber, Neutron Sciences Directorate
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.
Refreshments will be served, starting at 9:30 am.