Enthalpy of Formation of the Nitrogen-Rich Salt Guanidinium 5,5¿-Azotetrazolate (GZT) and a Simple Approach for Estimating the Enthalpy of Formation of Energetic C, H, N, O Salts

• Type: Article in International Scientific Journal
• Date: 2023

Authors

Silva, ALR (Author) FCUP; León, GP (Author) Other; Maria D M C R Ribeiro da Silva (Author) FCUP; Klapötke, TM (Author) Other; Reinhardt, J (Author) Other

Journal

The Journal is awaiting validation by the Administrative Services.

Title: Thermo

Vol. 3

Pages: 549-565

ISSN: 2673-7264

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-00Z-51X

DOI: 10.3390/thermo3040033

Abstract (EN): The discrepancy between the calculated (CBS-4M/Jenkins) and experimentally determined enthalpies of formation recently reported for the 2:1 salt TKX-50 raised the important question of whether the enthalpies of formation of other 2:1 C, H, N, O salts calculated using the CBS-4M/Jenkins method are reliable values. The standard (p degrees = 0.1 MPa) enthalpy of formation of crystalline guanidinium 5,5 '-azotetrazolate (GZT) (453.6 +/- 3.2 kJ/mol) was determined experimentally using static-bomb combustion calorimetry and was found to be in good agreement with the literature's values. However, using the CBS-4M/Jenkins method, the calculated enthalpy of formation of GZT was again in poor agreement with the experimentally determined value. The method we used recently to calculate the enthalpy of formation of TKX-50, based on the calculation of the heat of formation of the salt and of the corresponding neutral adduct, was then applied to GZT and provided excellent agreement with the experimentally determined value. Finally, in order to validate the findings, this method was also applied to predict the enthalpy of formation of a range of 1:1 and 2:1 salts (M+X- and (M+)2X2- salts, respectively), and the values obtained were comparable to experimentally determined values. The agreement using this approach was generally very good for both 1:1 and 2:1 salts; therefore, this approach provides a simple and reliable method which can be applied to calculate the enthalpy of formation of energetic C, H, N, O salts with much greater accuracy than the current, commonly used method.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 17