Liquid Mixtures Involving Hydrogenated and Fluorinated Alcohols: Thermodynamics, Spectroscopy, and Simulation

This article reports a combined thermodynamic, spectroscopic, and computational study on the interactions and structure of binary mixtures of hydrogenated and fluorinated substances that simultaneously interact through strong hydrogen bonding. Four binary mixtures of hydrogenated and fluorinated alcohols have been studied, namely, (ethanol + 2,2,2-trifluoroethanol (TFE)), (ethanol + 2,2,3,3,4,4,4-heptafluoro-1-butanol), (1-butanol (BuOH) + TFE), and (BuOH + 2,2,3,3,4,4,4-heptafluoro-1-butanol). Excess molar volumes and vibrational spectra of all four binary mixtures have been measured as a function of composition at 298 K, and molecular dynamics simulations have been performed. The systems display a complex behavior when compared with mixtures of hydrogenated alcohols and mixtures of alkanes and perfluoroalkanes. The combined analysis of the results from different approaches indicates that this results from a balance between preferential hydrogen bonding between the hydrogenated and fluorinated alcohols and the unfavorable dispersion forces between the hydrogenated and fluorinated chains. As the chain length increases, the contribution of dispersion increases and overcomes the contribution of H-bonds. In terms of the liquid structure, the simulations suggest the possibility of segregation between the hydrogenated and fluorinated segments, a hypothesis corroborated by the spectroscopic results. Furthermore, a quantitative analysis of the infrared spectra reveals that the presence of fluorinated groups induces conformational changes in the hydrogenated chains from the usually preferred all-trans to more globular arrangements involving gauche conformations. Conformational rearrangements at the CCOH dihedral angle upon mixing are also disclosed by the spectra.

Lisboa olhando o Rio: vestígios da coleção fluminense de Gastão Penalva (1887-1944)

Oficial da marinha brasileira, cronista e crítico, Gastão Penalva (1887- 1944) foi um coleccionador de cerâmica e profundo admirador de Rafael Bordalo Pinheiro (1846-1905), artista que conheceu muito jovem e lhe causou uma impressão inextinguível. Orgulhava-se de ter reunido no Rio de Janeiro o maior número de peças de cerâmica da Fábrica de Faianças das Caldas da Rainha fora de Portugal e afiançava que grande parte da colecção tinha o selo que correspondia ao tempo em que Bordalo foi seu Director Artístico. Tanto quanto se conseguiu apurar até ao momento, a memória desta colecção não se fixou de forma particular, nem de um lado, nem do outro do Atlântico. Em Lisboa existem alguns vestígios em cartas inéditas e fotografias que aqui se publicam pela primeira vez, testemunhando a relação entre museus e coleccionadores.

The marriage of João de Alarcão and Margarida Soares and the creation of a transnational Portuguese-Spanish nobility

The main aim of this chapter is to analyze the social and political effects of dynastic marriages between the Portuguese and Castilian-Aragonese crowns on the configuration of transnational, aristocratic families during the sixteenth and seventeenth centuries. To illustrate these questions we have chosen to follow the Soares de Alarcão family (known in Spain as Suárez de Alarcón) and the paths it took between the royal houses of Portugal and Castile for seven generations. The working hypothesis of the chapter is that the identity of the Iberian nobility during this era was characterized by a shared noble culture rather than by any particular features derived from the family’s land of origin. That assumption allows us to discuss whether the use of a particular language or culture indicates ties or political loyalties based on criteria of nationality, or, at the very least, place of birth. Therefore, this essay discusses the miscegenation of Iberian nobilities derived from dynastic marriages. It articulates the structural characteristics of this group and its political impact with the individual trajectories and historical contexts in which they developed. While these topics can be of interest for the comprehension of Portuguese early modern history, they can also help us to reflect more broadly on processes of identity construction.