Title
Dimers or trimers? A characterization of the halogen bonded complexes of <tex>$CF_{3}X$</tex> (X = I or Br) with dimethyl ether and acetone in cryosolutions Dimers or trimers? A characterization of the halogen bonded complexes of <tex>$CF_{3}X$</tex> (X = I or Br) with dimethyl ether and acetone in cryosolutions
Author
Faculty/Department
Faculty of Sciences. Chemistry
Publication type
article
Publication
Oxford ,
Subject
Physics
Chemistry
Source (journal)
Spectrochimica acta: part A: molecular and biomolecular spectroscopy. - Oxford
Volume/pages
171(2016) , p. 60-71
ISSN
1386-1425
Carrier
E
Target language
English (eng)
Affiliation
University of Antwerp
Abstract
Acetone molecules dissolved in liquid krypton are inclined to self-associate into dimers. This behavior affects its use as a prototype Lewis base in studies of weak intermolecular interactions. In this study infrared spectra of mixed solutions of dimethyl ether and CF3X and of acetone and CF3X (with X = I or Br) dissolved in liquid argon and liquid krypton are recorded at constant temperature. The dataset for dimethyl ether is used to validate a numerical method based on least-squares fitting of a model including contributions of both monomers and a heterodimer with 1:1 stoichiometry. The resulting monomer and dimer spectra show excellent agreement with previous studies found in literature. The analysis of the dataset for acetone requires an extension of the model with contributions for the acetone homodimer and for (acetone)2·CF3X and acetone·(CF3X)2 trimers. The results show that many signals for acetone·CF3I and (acetone)2·CF3I are observed, while only a few bands due to acetone·(CF3I)2 occur. The use of numerical approaches adjusted to the specificities of a mixture of two compounds allows to reliably resolve overlapping spectra of monomers and heterocomplexes and characterizing heterocomplex features that could not be deduced using earlier methods. To support the assignments made, ab initio calculations predicting geometries, relative stabilities and harmonic vibrational frequencies for the species envisaged are performed.
E-info
https://repository.uantwerpen.be/docman/iruaauth/ebb1a9/134485.pdf
Handle