Relation between the N-NO2 bond length and stability of the secondary nitramines

The fact of the constancy of activation entropy of N-NO2 bond homolysis in a series of secondary nitramines was utilized for correction of the experimental values of activation energy E of this process proceeding from the reliable data for the rate constants of the nitramines decomposition in solutions. When comparing the refined values of E (kJ mol−1) with the N-N bond length d N-N (Å) the following correlations were obtained: for cyclic and framework nitramines E = 663 − 356d N-N, and for the aromatic nitramines E = 1810 − 1227d N-N. A linear relationship between E and d is observed in the series of similar compounds. It depends on the electronic and steric effects of substituents.