title: The Uptake and Assembly of Alkanes within a Porous Nanocapsule in Water: New Information about Hydrophobic Confinement.
abstract: In Nature, enzymes provide hydrophobic cavities and channels for sequestering small alkanes or long-chain alkyl groups from water. Similarly, the porous metal oxide capsule [{Mo(VI) 6 O21 (H2 O)6 }12 {(Mo(V) 2 O4 )30 (L)29 (H2 O)2 }](41-) (L=propionate ligand) features distinct domains for sequestering differently sized alkanes (as in Nature) as well as internal dimensions suitable for multi-alkane clustering. The ethyl tails of the 29 endohedrally coordinated ligands, L, form a spherical, hydrophobic "shell", while their methyl end groups generate a hydrophobic cavity with a diameter of 11 Å at the center of the capsule. As such, C7 to C3 straight-chain alkanes are tightly intercalated between the ethyl tails, giving assemblies containing 90 to 110 methyl and methylene units, whereas two or three ethane molecules reside in the central cavity of the capsule, where they are free to rotate rapidly, a phenomenon never before observed for the uptake of alkanes from water by molecular cages or containers.
authors.affiliation: Department of Chemistry, Ben-Gurion University of the Negev and the Ilse Katz Institute for Nanoscale Science & Technology, Beer Sheva, 84105, Israel.
authors.forename: Sivil
authors.initials: S
authors.lastname: Kopilevich
authors.affiliation: Department of Chemistry, Bar-Ilan University, Ramat Gan, 529002, Israel.
authors.forename: Hugo
authors.initials: H
authors.lastname: Gottlieb
authors.affiliation: Department of Chemistry, Bar-Ilan University, Ramat Gan, 529002, Israel.
authors.forename: Keren
authors.initials: K
authors.lastname: Keinan-Adamsky
authors.affiliation: Fakultät für Chemie, Universität Bielefeld, Postfach 100131, 33501, Bielefeld, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Müller
authors.affiliation: Department of Chemistry, Ben-Gurion University of the Negev and the Ilse Katz Institute for Nanoscale Science & Technology, Beer Sheva, 84105, Israel. iraw@bgu.ac.il.
authors.forename: Ira A
authors.identifier: http://orcid.org/0000-0002-6701-2001
authors.initials: IA
authors.lastname: Weinstock
keywords: alkanes; confinement effect; hydrophobicity; molybdenum; porous capsules