title: Triggering the Chemical Instability of an Ionic Liquid under High Pressure.
abstract: Ionic liquids are an interesting class of materials due to their distinguished properties, allowing their use in an impressive range of applications, from catalysis to hypergolic fuels. However, the reactivity triggered by the application of high pressure can give rise to a new class of materials, which is not achieved under normal conditions. Here, we report on the high-pressure chemical instability of the ionic liquid 1-allyl-3-methylimidazolium dicyanamide, [allylC1im][N(CN)2], probed by both Raman and IR techniques and supported by quantum chemical calculations. Our results show a reaction occurring above 8 GPa, involving the terminal double bond of the allyl group, giving rise to an oligomeric product. The results presented herein contribute to our understanding of the stability of ionic liquids, which is of paramount interest for engineering applications. Moreover, gaining insight into this peculiar kind of reactivity could lead to the development of new or alternative synthetic routes to achieve, for example, poly(ionic liquids).
authors.affiliation: Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo , Av. Prof. Lineu Prestes 748, Sao Paulo 05508-000, Brazil.
authors.forename: Luiz F O
authors.initials: LF
authors.lastname: Faria
authors.affiliation: Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo , Av. Prof. Lineu Prestes 748, Sao Paulo 05508-000, Brazil.|LENS, European Laboratory for Nonlinear Spectroscopy , Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Marcelo M
authors.initials: MM
authors.lastname: Nobrega
authors.affiliation: Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo , Av. Prof. Lineu Prestes 748, Sao Paulo 05508-000, Brazil.
authors.forename: Marcia L A
authors.initials: ML
authors.lastname: Temperini
authors.affiliation: LENS, European Laboratory for Nonlinear Spectroscopy , Via Nello Carrara 1, 50019 Sesto Fiorentino, Florence, Italy.|Dipartimento di Chimica "Ugo Schiff" dell' Università degli Studi di Firenze , Via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bini
authors.affiliation: Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo , Av. Prof. Lineu Prestes 748, Sao Paulo 05508-000, Brazil.
authors.forename: Mauro C C
authors.initials: MC
authors.lastname: Ribeiro