Showing papers by "Josep Salud published in 1999"
TL;DR: In this article, five experimental two-component phase diagrams between orientationally disordered crystals (ODICs) have been established from the low-temperature phase to the liquid state using thermal analysis and X-ray powder diffraction techniques.
Abstract: Five experimental two-component phase diagrams between orientationally disordered crystals (ODICs) have been established from the low-temperature phase to the liquid state using thermal analysis and X-ray powder diffraction techniques. The high-temperature orientationally disordered phases for the pure components, which belong to the series (CH
3
)
4–n1
C(CH
2
OH)
n1
(n
1
=1,2,3) and (NO
2
)(CH
3
)
3–n2
C(CH
2
OH)
n2
(n
2
=0,1) are all face centered cubic. Continuous disordered mixed crystals in the whole range of concentration have been found, which indicates the existence of an isomorphism relationship. The intermolecular interactions in the ODIC state of these systems and other related two-component systems are discussed using the evolution of the packing coefficient as a function of the composition.
33 citations
TL;DR: In this article, the orientationally disordered stable and metastable mixed crystals of the two-component system methylchloroform ((CH3)CCl3)+ carbon tetrachloride (CCl4) have been characterised from a crystallographic and thermodynamic point of view.
31 citations
TL;DR: In this article, a thermodynamic analysis was made of a set of two-component systems displaying isomorphous orientationally disordered phases (ODIC), and the Equal Gibbs Curve method was used in order to determine the Gibbs excess energy of the disordered mixed crystals.
Abstract: A thermodynamic analysis was made of a set of two-component systems displaying isomorphous orientationally disordered phases (ODIC). The pure compounds are molecular materials belonging to the series (CH
3
)
4–
n1
C(CH
2
OH)
n1
(n
1
=1, 2, 3), (NO
2
)(CH
3
)
3–
n2
C(CH
2
OH)
n2
(n
2
=0, 1) and (NH
2
)(CH
3
)
3–
n3
C(CH
2
OH)
n3
(n
3
=2, 3). The Equal Gibbs Curve method was used in order to determine the Gibbs excess energy of the orientationally disordered mixed crystals. The excess Gibbs energies of the disordered phases obtained from the disordered-liquid equilibria were used on the analysis of the low-temperature ordered-disordered equilibria. This excess property was correlated for the mentioned chemically coherent group of materials (neopentane derivatives) studied in this work, with a crystallographic parameter, the packing coefficient, which accounts for the steric factors and intermolecular interactions in the disordered mixed crystals.
12 citations