A remarkable phenomenon: Carboxylates negotiate passage through flexible Mo9O9 pores of a 3 nm diameter “capsule-like” open-framework macroion that functions as soluble analog of a porous metal oxide. Branched-alkane substituted carboxylate “guests” enter the host/capsule even though they are larger than the size of the capsule’s metal-oxide pores.

Artwork by Pere Miro. All rights reserved by the American Chemical Society

Ziv, A.; Grego, A.; Kopilevich,  S.; Zeiri, L.; Miro, P.; Bo, C.; Müller, A.; Weinstock, I. A.* “Flexible Pores of a Metal-Oxide-Based Capsule Permit Entry of Comparatively Larger Organic Guests” J. Am. Chem. Soc. 2009, 131, 6380-6382.

Highlighted in Chemistry World, “Capsules with flexi-pores open wide”, March 19, 2009; Chemical & Engineering News, “Inorganic oxides maintain a flexible attitude” 2009, 87(14), 26-27 (April 6, 2009).

JACS Beta Image Challenge and Enhanced Cover-Art Podcast #11 (and below)

Highlighted on the cover of The Journal of the American Chemical Society, Volume 131 (18) (May 13, 2009).