Thermodynamique de composes azotes. X. Etude thermochimique de quelques acides Ο‰-amines
(EN)
Sabbah, S. Skoulika et R.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
(EL)
Sabbah, S. Skoulika et R.
(EN)
In order to determine energetical values for intra- and intermolecular bonds in w-aminoacids which have the zwitterion configuration within the crystal lattice H3N+-(CH,),-COO-, five compounds of this family for which n = 2, 3, 4, 5 and 7 were studied by calorimetry. The energies for Van der Waals and hydrogen bonds which link together the molecules in the crystal were determined from the values of the enthalpy of sublimation. A comparison of the experimental values for the enthalpy of formation of these compounds in the gaseous state with the values calculated using Benson"™s scheme, showed that w-aminoacids take the molecular structure in the vapour phase, resulting from a proton transfer which oc5urs in the crystalline state between two molecules linked together with a hydrogen bond (N-H.. .o + N . . . H-O) with rearrangement of the electronic charges in these molecules.
(EN)
