On the Crystallography and Thermodynamics in Orientationally Disordered Phases in Two-Component Systems

• Published in: Journal of solid state chemistry Vol. 133; no. 2; pp. 536 - 544
• Main Authors: Salud, J., López, D.O., Barrio, M., Tamarit, J.Ll, Oonk, H.A.J., Negrier, P., Haget, Y.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: San Diego, CA Elsevier Inc 01-11-1997; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Heat capacities of solids; Physics; Semi-periodic solids; Structure of solids and liquids; crystallography; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermodynamic properties; Intermolecular interaction; Temperature dependence; Disordered systems; Phase diagrams; Orientation disorder; Stacking sequence; Phase transformations; XRD; Experimental study; Thermodynamic properties; Polymorphism; Crystal structure
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.1997.7530

The experimental two-component phase diagram between the orientationally disordered crystals 2-amino-2-methyl-1,3-propanediol (AMP) and 1,1,1-tris(hydroxymethyl)propane (PG) has been established from room temperature to the liquid state using thermal analysis and X-ray powder diffraction techniques. The intermolecular interactions in the orientationally disordered mixed crystals of the mentioned system and other related two-component systems are discussed by analyzing the evolution of the packing coefficient as a function of the the composition. A thermodynamic analysis of the presented phase diagram and the redetermined AMP/NPG (2,2-dimethyl-1,3-propanediol) is reported on the basis of the enthalpy–entropy compensation theory.