Monitoring the Solution Persistence of Porous Coordination Cages with Diffusion NMR Spectroscopy and Cryogenic Transmission Electron Microscopy

Research Focus

• Diffusion NMR spectroscopy, transmission electron microscopy, and cryogenic transmission electron spectroscopy were used to characterize porous cages in solution.
• A combination of the methods can be used to discriminate between assembled cages as opposed to decomposed or isomerized materials while dissolved in polar organic solvents, regardless of the metal cations used in their assembly.

Key Advances

• Diffusion NMR spectroscopy was used to confirm the presence of assembled cages in solution, even when the paramagnetic nature of their constituent metal cations obscure NMR interpretation in other experiments.
• Fragments of analogous cages were prepared and used to show the method is viable for these structures.
• TEM and cryo-TEM both confirm that these cages, which can be highly dynamic in solution, persist under the conditions we employed.

Interdisciplinary Research Group (IRG) 1: Peptide Active Materials (PAMs)