Chemical routes to atomic nitrogen
Chapter 1 contains a general introduction and review of the field of atomic nitrogen chemistry. Included here is mention of the occurrences, generation, detection and analysis, reactions and uses of atomic nitrogen. A summary of previous work towards the chemical generation of atomic nitrogen in solution is given, this being stated as the overall aim of the thesis. This aim encompasses bond-breaking: (a) in nitrogen containing heterocycles upon mild photolysis or thermolysis, (b) in azidyl radicals. Chapter 2 describes the benzocinnoline N-imine system along with its isomeric 5H-dibenzo[1,2,3][d,f]triazepine with a view to the selective derivatisation of the latter. The photochemical and oxidative reactions of these systems are investigated by esr. 1H-Benzotriazole and selected derivatives are examined as triazenyl models for the triazepinyl system. Chapter 3 considers the chemistry of the 1,3,4-dioxazol-2-ones particularly the unreported 5-O-linked derivatives which are sought as possible precursors to the novel 1,3,4-dioxazolidine-2,5-diones themselves potential atomic nitrogen precursors. Chapter 4 concerns the 1,2,4-dithiazolidine-3,5-diones as potential atomic nitrogen precursors and two routes are pursued to the little reported unsubstituted parent 1,2,4-dithiazolidinedione. Chapter 5 departs from the heterocyclic theme of chapters 2-4 and considers the generation and fragmentation of the azidyl radical as a possible source of atomic nitrogen. Evidence for the production of atomic nitrogen from this radical, generated from the persulphate oxidation of azide anion, is discussed.