Photochemistry inside the cavities of coordination cages

Rafal Klajn

Nature inspires chemists with abilities to develop strategies for stabilizing ephemeral chemical species, performing chemical reactions with unprecedented rates and selectivities, and synthesizing complex molecules and exquisite inorganic nanostructures. What natural systems consistently exploit—which is yet fundamentally different from how chemists perform reactions—is the aspect of nanoscale confinement. Our research focuses on studying the behavior of chemical species within various types of nanoconfined environments, including surfaces of colloidal nanoparticles, cavities within coordination cages, and nanopores within porous materials (such as porous aromatic frameworks). We also develop novel families of synthetic materials featuring confined spaces; examples include reversibly self-assembling colloidal crystals (“dynamic nanoflasks”), bowl-shaped metallic nanoparticles, and non–close-packed nanoparticle superlattices. While these objectives are predominantly fundamental, they can also generate an array of applications. Our ultimate goals are as diverse as preparing a new family of inverse opals, studying protein folding inside “artificial chaperones”, and controlling polymerization reactions according to the size and shape of the “nanoflask”. We believe that studying chemistry under nanoconfinement has the potential to teach us novel ways to perform chemical reactions, paving the way to discovery of new phenomena and unique structures.