American Chemical Society
ja503223j_si_004.cif (8.26 kB)

Acid- and Base-Stable Porous Organic Cages: Shape Persistence and pH Stability via Post-synthetic “Tying” of a Flexible Amine Cage

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posted on 2014-05-28, 00:00 authored by Ming Liu, Marc A. Little, Kim E. Jelfs, James T. A. Jones, Marc Schmidtmann, Samantha Y. Chong, Tom Hasell, Andrew I. Cooper
Imine cage molecules can be reduced to amines to improve their chemical stability, but this introduces molecular flexibility. Hence, amine cages tend not to exhibit permanent solid-state porosity. We report a synthetic strategy to achieve shape persistence in amine cages by tying the cage vertices with carbonyls such as formaldehyde. Shape persistence is predicted by conformer stability calculations, providing a design basis for the strategy. The tied cages show enhanced porosity and unprecedented chemical stability toward acidic and basic conditions (pH 1.7–12.3), where many other porous crystalline solids would fail.