Decomplexation and complexation of alkali metal cations by a crown-ether-type podand in dichloromethane: a steered molecular dynamics study

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Mario Valente (Author) Other; Sergio Filipe Sousa (Author) FCUP; Magalhaes, AL (Author) FCUP; Cristina Freire (Author) FCUP

Journal

Title: Theoretical Chemistry Accounts

Vol. 131 No. 3

Pages: 1-7

ISSN: 1432-881X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 4 Citations

Scopus - 4 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-CDA

DOI: 10.1007/s00214-012-1171-5

Abstract (EN): The decomposition of three complexes involving the alkali metal cations Li+, Na+ and K+ and a potentially octadentate polyethylene-glycol-type podand(1,2-bis-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-benzene, hereafter b33) in dichloromethane was studied by steered molecular dynamics (SMD). This technique proved applicable to the problem. Analysis of the resulting trajectories allowed phenomenological descriptions of the decomposition processes. Use of the Jarzynski identity allowed the estimation of the corresponding free energies, which in turn allowed the estimation of the complex formation free energies in dichloromethane. These are very similar to the experimental values determined by liquid-liquid extraction, as long as a strong reduction of the podand denticity is considered, possibly due to the presence of competing water molecules. To the best of our knowledge, the present study is the first to use SMD to address the problem of determination of the free energies involved in the complexation of alkali cations by an extraction agent (here a podand), in a bulk solvent (here dichloromethane).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7