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ID 40789
file
creator
Morishima, Fumiya
Dedonder, Claude
Feraud, Geraldine
Jouvet, Christophe
NDC
Chemistry
abstract
The geometric and electronic structures of cold host-guest complex ions of crown ethers (CEs) in the gas phase have been investigated by ultraviolet (UV) fragmentation spectroscopy. As host CEs, we chose 15-crown-5 (15C5), 18-crown-6 (18C6), 24-crown-8 (24C8), and dibenzo-24-crown-8 (DB24C8), and as guests protonated-aniline (aniline•H+) and protonated-dibenzylamine (dBAM•H+) were chosen. The ions generated by an electrospray ionization (ESI) source were cooled in a quadrupole ion-trap (QIT) by cryogenic cooler, and the UV spectra were obtained by UV photodissociation (UVPD) spectroscopy. The UV spectroscopy was complemented by quantum chemical calculations of the most probable complex structures. The UV spectrum of aniline•H+•CE is very sensitive to the symmetry of CE; aniline•H+•18C6 shows sharp electronic spectrum similar to aniline•H+, while aniline•H+•15C5 shows very broad structure with poor Franck-Condon factors. In addition, a remarkable cage effect in the fragmentation process after UV excitation was observed in both complex ions. In the aniline•H+•CE complexes, the cage effect completely removed the dissociation channels of the aniline•H+ moiety. A large difference in the fragmentation yield between dBAM•H+•18C6 and dBAM•H+•24C8 was observed due to a large barrier for releasing dBAM•H+ from the axis of rotaxane in the latter complex.
description
This study was supported in part by the France-Japan Collaboration Program (SAKURA), the Japan Society for Promotion of Science and the ANR Research Grant (ESPEM- ANR2010BLANC040501).
journal title
Physical Chemistry Chemical Physics
volume
Volume 17
issue
Issue 39
start page
25925
end page
25934
date of issued
2015-10-21
publisher
Royal Society of Chemistry
issn
1463-9076
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
Copyright (c) the Owner Societies 2015
This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.
relation is version of URL
http://doi.org/10.1039/C5CP01960E
department
Graduate School of Science