ABSTRACT
Radiolysis of Polymers .................................................................. 43 4.3 Radical Reactions Initiated by Nitrogen Trioxide ......................... 46 4.4 Free Radical and Ion-Radical Reactions under Action
of Nitrogen Dioxide and its Dimers ............................................... 48 4.4.1 Preparation of Spin-Labelled Rubbers ............................... 49 4.4.2 On the Mechanism of Initiation of Radical Reactions by
Nitrogen Dioxide Dimers ................................................... 52 4.5 AB Initio Calculations of Energies for Conversions of Nitrogen
Dioxide Dimmers ........................................................................... 58 4.6 Detecting Radical Cations in Reactions of Electron
Transfer to NN ............................................................................... 60 4.7 Conclusion ..................................................................................... 62 Keywords ................................................................................................ 63 References ............................................................................................... 63
4.1 INTRODUCTION
Nitrogen oxides play the important role in various chemical processes proceeding in an atmosphere, and affect on an environment [1-4]. These compounds ejected to atmosphere by the factories and transport in huge amounts creates thus serious problems for fauna and flora as well as synthetic polymeric materials. In this connection, the researches of the mechanism of nitrogen oxide reactions with various organic compounds including polymers are important for definition of stability of these materials in polluted atmosphere. On the other hand, these researches can be used in synthetic chemistry [5-7], in particular for development of methods of the polymer modification, for example, for preparation of spin-labelled macromolecules [8, 9]. The generation of spin labels occurs thus in consecutive reactions including formation and conversion of specific intermediate molecular products and active free radicals. It is necessary to note essential advantages of such way of obtaining spin labels not requiring application of complex synthetic methods based on reactions of stable nitroxyl radicals with functional groups of macroradicals [10]. If the polymers are capable of reacting with nitrogen oxides, the formation of stable radicals in them takes place spontaneously or by thermolysis of molecular products of nitration [11, 12].
