title: A thermochromic europium(iii) room temperature ionic liquid with thermally activated anion-cation interactions.
abstract: We report the first example of an observable and reversible case of thermochromism due to the interaction of an alkylphosphonium (P6,6,6,14)+with a β-diketonate (1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dionate-fod) of an europium(iii) tetrakis-β-diketonate room temperature ionic liquid. This thermochromism is characterized by the conversion of a light yellow viscous liquid, at room temperature, to a reddish substance close to 80 °C. The reversibility of this optical effect was highlighted by the thermal stability of the Eu(iii) complex.
authors.affiliation: Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, Campus Tecnológico e Nuclear, Estrada Nacional 10, ao km 139,7, 2695-066 Bobadela, Portugal. jpleal@ctn.ist.utl.pt.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Monteiro
authors.affiliation: REQUIMTE, Dep. de Química, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal. ccl.pereira@fct.unl.pt catl@fct.unl.pt.
authors.forename: Mani
authors.initials: M
authors.lastname: Outis
authors.affiliation: REQUIMTE, Dep. de Química, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal. ccl.pereira@fct.unl.pt catl@fct.unl.pt.
authors.forename: Hugo
authors.initials: H
authors.lastname: Cruz
authors.affiliation: Centro de Ciências e Tecnologias Nucleares (C2TN), Instituto Superior Técnico, Universidade de Lisboa, Campus Tecnológico e Nuclear, Estrada Nacional 10, ao km 139,7, 2695-066 Bobadela, Portugal. jpleal@ctn.ist.utl.pt and Centro de Química e Bioquímica-Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: João Paulo
authors.identifier: http://orcid.org/0000-0003-1235-0107
authors.initials: JP
authors.lastname: Leal
authors.affiliation: REQUIMTE, Dep. de Química, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal. ccl.pereira@fct.unl.pt catl@fct.unl.pt.
authors.forename: César A T
authors.initials: CA
authors.lastname: Laia
authors.affiliation: REQUIMTE, Dep. de Química, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal. ccl.pereira@fct.unl.pt catl@fct.unl.pt.
authors.forename: Cláudia C L
authors.identifier: http://orcid.org/0000-0003-3421-8676
authors.initials: CC
authors.lastname: Pereira