Journal article
Flexible Pores of a Metal Oxide-Based Capsule Permit Entry of Comparatively Larger Organic Guests
Journal of the American Chemical Society, Vol.131(18), pp.6380-6382
05/13/2009
DOI: 10.1021/ja900452d
PMID: 19290673
Abstract
In zeolites and other rigid solid-state oxides, substrates whose sizes exceed the pore dimensions of the material are rigorously excluded. Now, using a porous 3 nm diameter capsule-like oxomolybdate complex [{(Mo6O21)-O-VI(H2O)(6)}(12){((Mo2O4)-O-V)(30)(OAc)(21)(H2O)(18})](33-) as a water-soluble analogue of solid-state oxides (e.g., as a soluble analogue of 3 A molecular sieves), we show that carboxylates (RCO2-) can negotiate passage through flexible Mo9O9 pores in the surface of the capsule and that the rates follow the general trend R = 1 degrees >> 2 degrees > 3 degrees >> phenyl (no reaction). Surprisingly, the branched alkanes (R = iso-Pr and tert-Bu) enter the capsule even though they are larger than the crystallographic dimensions of the Mo9O9, pores. Four independent lines of spectroscopic and kinetic evidence demonstrate that these organic guests enter the interior of the capsule through its Mo9O9 apertures and that no irreversible changes in the metal oxide framework are involved. This unexpected phenomenon likely reflects the greater flexibility of molecular versus solid-state structures and represents a sharp departure from traditional models for diffusion through porous solid-state (rigid) oxides.
Details
- Title: Subtitle
- Flexible Pores of a Metal Oxide-Based Capsule Permit Entry of Comparatively Larger Organic Guests
- Creators
- Ayala Ziv - Ben-Gurion University of the NegevAlina Grego - Ben-Gurion University of the NegevSivil Kopilevich - Ben-Gurion University of the NegevLeila Zeiri - Ben-Gurion University of the NegevPere Miro - Ben-Gurion University of the NegevCarles Bo - Ben-Gurion University of the NegevAchim Mueller - Univ Bielefeld, Fac Chem, D-33501 Bielefeld, GermanyIra A. Weinstock - Ben-Gurion University of the Negev
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.131(18), pp.6380-6382
- Publisher
- Amer Chemical Soc
- DOI
- 10.1021/ja900452d
- PMID
- 19290673
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Number of pages
- 5
- Grant note
- Toman Foundation Deutsche Forschungsgmeinschaft 1720/08 / ISF; Israel Science Foundation CSD2006-0003 / Consolider Ingenio; Ministry of Science and Innovation, Spain (MICINN); Spanish Government
- Language
- English
- Date published
- 05/13/2009
- Academic Unit
- Chemistry
- Record Identifier
- 9984618646102771
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