posted on 2014-05-28, 00:00authored byMing 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.