Počet záznamů: 1
Surface Behavior of Hydrated Guanidinium and Ammonium Ions: A Comparative Study by Photoelectron Spectroscopy and Molecular Dynamics
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SYSNO ASEP 0430362 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Surface Behavior of Hydrated Guanidinium and Ammonium Ions: A Comparative Study by Photoelectron Spectroscopy and Molecular Dynamics Tvůrce(i) Werner, J. (SE)
Wernersson, Erik (UOCHB-X)
Ekholm, V. (SE)
Ottosson, N. (SE)
Öhrwall, G. (SE)
Heyda, Jan (UOCHB-X)
Persson, I. (SE)
Söderström, J. (SE)
Jungwirth, Pavel (UOCHB-X) RID, ORCID
Björneholm, O. (SE)Celkový počet autorů 10 Zdroj.dok. Journal of Physical Chemistry B. - : American Chemical Society - ISSN 1520-6106
Roč. 118, č. 25 (2014), s. 7119-7127Poč.str. 9 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova XPS ; MD simulations ; aqueous solutions ; air/water interface ; liquid micro-jet Vědní obor RIV CF - Fyzikální chemie a teoretická chemie CEP GBP208/12/G016 GA ČR - Grantová agentura ČR Institucionální podpora UOCHB-X - RVO:61388963 UT WOS 000338184400014 EID SCOPUS 84903466740 DOI 10.1021/jp500867w Anotace Through the combination of surface sensitive photoelectron spectroscopy and molecular dynamics simulation, the relative surface propensities of guanidinium and ammonium ions in aqueous solution are characterized. The fact that the N Is binding energies differ between these two species was exploited to monitor their relative surface concentration through their respective photoemission intensities. Aqueous solutions of ammonium and guanidinium chloride, and mixtures of these salts, have been studied in a wide concentration range, and it is found that the guanidinium ion has a greater propensity to reside at the aqueous surface than the ammonium ion. A large portion of the relative excess of guanidinium ions in the surface region of the mixed solutions can be explained by replacement of ammonium ions by guanidinium ions in the surface region in combination with a strong salting-out effect of guanidinium by ammonium ions at increased concentrations. This interpretation is supported by molecular dynamics simulations, which reproduce the experimental trends very well. The simulations suggest that the relatively higher surface propensity of guanidinium compared with ammonium ions is due to the ease of dehydration of the faces of the almost planar guanidinium ion, which allows it to approach the water-vapor interface oriented parallel to it. Pracoviště Ústav organické chemie a biochemie Kontakt asep@uochb.cas.cz ; Kateřina Šperková, Tel.: 232 002 584 ; Jana Procházková, Tel.: 220 183 418 Rok sběru 2015
Počet záznamů: 1