To a better understanding of silver and mercury fulminates thermochemistry

Abstract

In the present work are calculated, for the first time, the lattice energies (kJmol−1) for mercury and silver fulminates (by using the Glasser-Jenkins equations): Hg(CNO)2 = 1399.1, Ag(CNO), orthorhombic = 389.5 and Ag(CNO), rhombohedral = 305.1 (assuming the following charges: Hg: +2, Ag: +1 and CNO: −1). By using SE-PM6 molecular modelling, the “real” charges were calculated, and the “corrected” UPOT values (kJmol−1) are: Hg(CNO)2 = 777.0, Ag(CNO), orthorhombic = 107.2 and Ag(CNO), rhombohedral = 83.97. By using absolute chemical hardness values, the specific impulse (Is) values are 217.05 s and 178.41 s, for Hg(CNO)2 and Ag(CNO), respectively. The following empirical equation was derived: D = 10 Is n (where D is the detonation velocity (ms−1, Is is the specific impulse and n is the number of CNO– per formulae). The gas phase explosion enthalpies (kJmol−1) are: Hg(CNO)2 = -420.6 and Ag(CNO) = -164.4. The sublimation enthalpy for mercury fulminate was calculated as 51.9 kJmol−1. Others relationship between thermochemical data to mercury and silver fulminates were also established.