Self-Assembly through Noncovalent Preorganization of Reactants: Explaining the Formation of a Polyfluoroxometalate.

Autor: Schreiber RE; Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel., Avram L; Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 76100, Israel., Neumann R; Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, 76100, Israel.
Jazyk: angličtina
Zdroj: Chemistry (Weinheim an der Bergstrasse, Germany) [Chemistry] 2018 Jan 09; Vol. 24 (2), pp. 369-379. Date of Electronic Publication: 2017 Dec 08.
DOI: 10.1002/chem.201704287
Abstrakt: High-order elementary reactions in homogeneous solutions involving more than two molecules are statistically improbable and very slow to proceed. They are not generally considered in classical transition-state or collision theories. Yet, rather selective, high-yield product formation is common in self-assembly processes that require many reaction steps. On the basis of recent observations of crystallization as well as reactions in dense phases, it is shown that self-assembly can occur by preorganization of reactants in a noncovalent supramolecular assembly, whereby directing forces can lead to an apparent one-step transformation of multiple reactants. A simple and general kinetic model for multiple reactant transformation in a dense phase that can account for many-bodied transformations was developed. Furthermore, the self-assembly of polyfluoroxometalate anion [H 2 F 6 NaW 18 O 56 ] 7- from simple tungstate Na 2 WO 2 F 4 was demonstrated by using 2D 19 F- 19 F NOESY, 2D 19 F- 19 F COSY NMR spectroscopy, a new 2D 19 F{ 183 W} NMR technique, as well as ESI-MS and diffusion NMR spectroscopy, and the crucial involvement of a supramolecular assembly was found. The deterministic kinetic reaction model explains the reaction in a dense phase and supports the suggested self-assembly mechanism. Reactions in dense phases may be of general importance in understanding other self-assembly reactions.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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