Statistic-Driven Proton Transfer Affecting Nanoscopic Organization in an Ethylammonium Nitrate Ionic Liquid and 1,4-Diaminobutane Binary Mixture: A Steamy Pizza Model
1
Department of Chemistry, La Sapienza University of Rome, piazzale Aldo Moro 5, 00185 Rome, Italy
2
Helmholtz Institute Ulm (HIU), Helmholtzstrasse 11, 89081 Ulm, Germany
3
Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe, Germany
4
Department of Chemistry and NIS Interdepartmental Centre and INSTM Reference Centre, University of Turin, via Pietro Giuria 7, 10125 Turin, Italy
*
Authors to whom correspondence should be addressed.
Symmetry 2019, 11(11), 1425; https://doi.org/10.3390/sym11111425
Received: 8 October 2019 / Revised: 13 November 2019 / Accepted: 15 November 2019 / Published: 19 November 2019
(This article belongs to the Special Issue Materials Science and X-Ray Diffraction)
Herein, we report on the theoretical and experimental investigation of the chemical equilibrium in a Ethylammonium Nitrate (EAN)/1,4-Diaminobutane (DAB) binary mixture displaying a significant excess of the latter component (namely, a 1:9 mole ratio). Both the neutral compounds, i.e., ethylamine (EtNH2) and DAB, present very similar chemical properties, especially concerning their basic strength, resulting in a continuous jump of the proton from the ethylammonium to the diamine (and vice-versa). Due to the significant excess of DAB, the proton is (statistically) expected to be bound to one of its nitrogen atoms, leading to the formation of a new (ternary) mixture containing DAB (ca. 80%), ethylamine (ca. 10%) and 4-amino-1-butylammonium nitrate (ABAN, ca. 10%). This is probed by means of SAXS measurements, showing LqE (low q excess) that increases over time. This feature tends to stabilize after approximately one day. When the measurement is repeated after one year, the LqE feature shows an increased intensity. Based on the results of our simulations, we suggest that this phenomenon is likely due to partial ethylamine evaporation, pushing the equilibrium toward the formation of ABAN.
View Full-Text
Keywords:
Ionic liquids; binary mixtures; proton transfer; SAXS; molecular dynamics
▼
Show Figures
Graphical abstract
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
MDPI and ACS Style
Mariani, A.; Bonomo, M.; Passerini, S. Statistic-Driven Proton Transfer Affecting Nanoscopic Organization in an Ethylammonium Nitrate Ionic Liquid and 1,4-Diaminobutane Binary Mixture: A Steamy Pizza Model. Symmetry 2019, 11, 1425.
Show more citation formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
