Authors: G. Barone and R. Puliti
View More View Less
Restricted access

Abstract  

In this paper a review of recent results concerning thermodynamic properties of solid uncharged derivatives of some amino acids and small peptides is reported. The experimental data obtained by different calorimetric methods are: sublimation enthalpies, heat capacities, enthalpies and temperatures of fusion and, in few cases, enthalpies and temperatures of solid-to-solid transitions. The standard molar and specific enthalpies and entropies of sublimation at 298.15 K have been calculated integrating the heat capacities of solids and vapours as function of temperature or directly measuring by calorimetry the heating enthalpies. The first ones have been obtained by interpolation of the values calculated according to the group additivity method of Benson. The sublimation thermodynamic properties have regarded N-acetylamides of glycine (NAGA), L-alanine (L-NAAA), L-valine (L-NAVA), D- and L-leucine (D-NALA and L-NALA, respectively) and L-isoleucine (L-NAIA) as well as the cyclic dipeptides glycyl-glycine (c-Gly-Gly), glycyl-L-alanine (c-Gly-L-Ala), L-alanyl-L-alanine (c-L-Ala-L-Ala) and sarcosyl-sarcosine (c-Sar-Sar). Heat capacities of the solid phases have been included also for N-acetylamide of L-proline (L-NAPA), N-methyl derivatives of the N-acetylamides previously cited and other amino acids, such as phenylalanine (F), isobutyric acid (isoBu), norvaline (norV) and norleucine (norL). In the text these substances are indicated as NAFAMe, etc. The heat capacities of their racemes are also reported. The fusion properties have concerned only two raceme mixtures (D,L-NAAA and D,L-NALA) and N-acetylamides of the cited amino acids, sarcosine (NASarA) and the following di-or tripeptides: glycyl-L-alanine (NAGAA), L-alanyl-L-alanine (NAA2A), glycyl-L-proline (NAGPA), L-prolyl-glycine (NAPGA), L-leucyl-L-proline (NALPA) and L-prolyl-L-leucyl-glycine (NAPLGA). Finally, solid-to-solid transitions have been found and characterized for L-NALA and NAGPA. All thermodynamic properties are discussed in the light of the crystal packing parameters determined during parallel crystallographic studies. It allows a comprehensive rationale of the behaviour of the solid state and its transitions for this interesting family of substances.

Manuscript Submission: HERE

  • Impact Factor (2019): 2.731
  • Scimago Journal Rank (2019): 0.415
  • SJR Hirsch-Index (2019): 87
  • SJR Quartile Score (2019): Q3 Condensed Matter Physics
  • SJR Quartile Score (2019): Q3 Physical and Theoretical Chemistry
  • Impact Factor (2018): 2.471
  • Scimago Journal Rank (2018): 0.634
  • SJR Hirsch-Index (2018): 78
  • SJR Quartile Score (2018): Q2 Condensed Matter Physics
  • SJR Quartile Score (2018): Q2 Physical and Theoretical Chemistry

For subscription options, please visit the website of Springer.

Journal of Thermal Analysis and Calorimetry
Language English
Size A4
Year of
Foundation
1969
Volumes
per Year
4
Issues
per Year
24
Founder Akadémiai Kiadó
Founder's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Publisher Akadémiai Kiadó
Springer Nature Switzerland AG
Publisher's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
CH-6330 Cham, Switzerland Gewerbestrasse 11.
Responsible
Publisher
Chief Executive Officer, Akadémiai Kiadó
ISSN 1388-6150 (Print)
ISSN 1588-2926 (Online)