title: Thermal and structural study of the crystal phases and mesophases in the lithium and thallium(i) propanoates and pentanoates binary systems: formation of mixed salts and stabilization of the ionic liquid crystal phase.
abstract: The temperature and enthalpy vs composition phase diagrams of the binary systems [xC(2)H(5)CO(2)Li + (1 - x)C(2)H(5)CO(2)Tl], and [x(n-C(4)H(9)CO(2)Li) + (1 - x)n-C(4)H(9)CO(2)Tl], where x is the mole fraction, were determined by DSC. Both binary systems display the formation of one 2:1 mixed salt each (at x = 0.667) that appear as a peritectic (incongruent melting) at T(fus) = 512.0 K, and T(fus) = 461.1 K, with Delta(fus)H(m) = 13.76 and 8.08 kJ.mol(-1) for Li-Tl (I) propanoates, and n-pentanoate mixed salts, respectively. The thermotropic liquid crystal of the thallium(I) n-pentanoate transforms into a more stable liquid-crystal phase, which appears in the phase diagram between 380 and 488 K and for x = 0 up to x = 0.56. The crystal structure of thallium(I) propanoate and of the two mixed salts were obtained via X-ray synchrotron radiation diffraction measurements. These compounds present a bilayered structure similar to the two pure lithium salts previously found by our group.
authors.affiliation: BM16-Laboratori de Llum Sincrotó (LLS), c/o European Synchrotron Radiation Facility, 38043 Grenoble, France.
authors.forename: F J
authors.initials: FJ
authors.lastname: Martínez Casado
authors.forename: M
authors.initials: M
authors.lastname: Ramos Riesco
authors.forename: I
authors.initials: I
authors.lastname: da Silva
authors.forename: A
authors.initials: A
authors.lastname: Labrador
authors.forename: M I
authors.initials: MI
authors.lastname: Redondo
authors.forename: M V
authors.initials: MV
authors.lastname: García Pérez
authors.forename: S
authors.initials: S
authors.lastname: López-Andrés
authors.forename: J A
authors.initials: JA
authors.lastname: Rodríguez Cheda