Experimental solid-liquid equilibria for systems containing alkan-1-ol+1,3-diaminopropane - Heat capacities of alkan-1-ols and amines - Thermodynamic functions of dissociation and enthalpies of melting of the congruently melting compounds for the sys

摘要

Solid-liquid phase diagrams (SLE) have been determined for (octan-1-ol, or nonal-1-ol, or decan-1-ol, or undecan-1-ol+1,3-diaminopropane) mixtures. Solid addition compounds form with the empirical formulae: {(C8H17OH)(2)center dot C3H10N2}, {(C9H19OH)(2)center dot C3H10N2}, {(C10H21OH)(2)center dot C3H10N2}, {(C11H23OH)(2)center dot C3H10N2}. All these compounds are congruently melting compounds. Compound formation is attributed to a strong A-B interaction. An alkan-1-ol and amine are associated by formation O-H center dot center dot center dot O and N-H center dot center dot center dot N hydrogen bonds. Strong cross association between the hydroxyl and the amine group (OH center dot center dot center dot NH2) is the dominant effect and a 2:1 congruently melting solid compound is formed at low temperatures. Standard thermodynamic functions of the dissociation of the compound have been calculated.The paper includes basic thermodynamic properties of pure substances-the enthalpy of fusion, the difference in the solute heat capacity between the liquid and solid phase at the melting temperature, determined by the differential scanning calorimetry (DSC) for alkan-1-ols (nonan-1-ol, decan-1-ol and undecan-1-ol) and amines (hexylamine, octylamine, decylamine, 1,3-diaminopropane). The values of the enthalpies of fusion of congruently melting compounds in the binary systems (an alkan-1-ol + amine) are also presented. (c) 2005 Elsevier B.V. All rights reserved.