Investigation of the Correlations Between Nitro Group Charges and Some Properties of Nitro Organic Compounds

摘要

The so-called nitro group charge method(NGCM)is successfully established to investigate some properties of nitro compounds including the molecular stability measured by total energy(only for isomers),the bond lengths,bond dissociation energies(BDE),and the nitrating activities,in that the method considers the molecular structure.These properties are intrinsically and especially thermodynamically consistent with each other and can be well related qualitatively and even quantitatively with nitro group charges(Q_(Nitro)).The correlations between Q_(Nitro)and the properties are:(1)for nitro isomers,the more negative the average Q_(Nitro),the lower the total energy and the more stable is the isomer;(2)for any separate group of nitro compounds,the more negative Q_(Nitro),the shorter the R-nitro bond length;(3)for the bond dissociation energy,more negative Q_(Nitro)corresponds to a higher BDE of the R-nitro bond;(4)by NGCM,the conditions,the reaction rates and the occurrence ratios of products of some nitration can be predicted and compared:the more negative Q_(Nitro)of the product,the easier and faster the nitration,and the higher the occurrence ratio of the corresponding product.