Recent efforts have established the possibility of pharmaceutical applications for several nitrate ester salts, and their Abstract: Nitrate (anion) salts with nitroxy-functionalized ammonium cations were synthesized. Several revealed surprising thermal and hydrolytic stability. Various physical properties were measured, and Gibbs free energy (DG r (298)) differences between the salts and postulated products of their thermal decomposition were computed. The computed differences indicate that salts with cations that have more than one nitroxy group are endothermic at 298 K. Nevertheless, the stability observed for some salts with this property indicates that kinetic barriers are sufficient to prevent facile decomposition at this temperature. This is in contrast to the case observed for nitrate salts of nitroxy-functionalized ammonium cations with acidic protons.

The interactions between nitrate plasticizer ingredients nitroglycerine, diethylene glycol dinitrate (DEGDN), and triethylene glycol dinitrate (TEGDN) have been investigated theoretically and experimentally. Density functional theory (DFT) and second order perturbation theory (MP2) calculations show that intermolecular N−O electrostatic interactions and hydrogen bonding between alkyl hydrogens and oxygen atoms govern the dimer structures, which have predicted binding energies ranging from 20.6 to 39.3 kJ mol−1. Vibrational frequencies observed in the nitrate band fingerprint region of the infrared spectra are in good agreement with the DFT scaled harmonic frequencies. The relative volatility observed in thermal gravimetric analysis (TGA) measurements of the pure ingredients and their 1 : 1 mixtures show reasonable correlation with the DFT dimer binding energies. The similarity in the dimer binding energies of all three plasticizers suggest that their mixtures should be uniformly miscible.

The back cover picture shows computed molecular electrostatic potentials (top left) and selected heterogeneous dimer interactions (top right) of nitrate plasticizer ingredients nitroglycerine (NG), diethylene glycol dinitrate (DEGDN), and triethylene glycol dinitrate (TEGDN), used as a qualitative assessment of the expected degree of miscibility between these ingredients in propellant formulations. The general similarity in the binding energies of homogenous and heterogeneous dimers, highlighted by a network of hydrogen bonds between alkyl hydrogens and the ether or nitrate oxygen atoms, suggests these plasticizers should be miscible. Predicted infrared vibrational spectra of the TEGDN‐TEGDN, DEGDN‐DEGDN, and TEGDN‐DEGDN dimers are in good qualitative agreement with the corresponding experimental spectra of TEDGN, DEGDN, and their 1:1 mixture (bottom left). Further details are presented in the Short Communication by Buszek et al. on page 115 ff.