Ethylene with active nitrogen

Fig. 4-5. Yields of HCN and 14N15N from the reaction of active nitrogen with 15NO-C2H4 mixtures ranging in composition from pure C2H4 to pure 15NO. The symbols ( ) and (O) represent experiments in which the ethylene flow rate was maintained at values in excess of titration end point while increasing increments of nitric oxide were added. The symbols ( ) and ( ) correspond to experiments in which nitric oxide flow rates were held at values in excess of titration end point while various amounts of ethylene were added (from Fersht and Back139 with permission of the National Research Council of Canada).

The most reliable results were obtained by Levy and Winkler (68) who investigated five different methods of terminating the reaction of active nitrogen with ethylene in the temperature range 22-400°C. The... 

Some controversy exists over the reactive species produced when nitrogen is passed through an R.f. or microwave discharge. Verbeke and Winkler investigated the reactions of active nitrogen with nitric oxide and ethylene and found that the amount of nitric oxide removed was greater than the maximum amount of HCN produced from ethylene. To account for this difference they postulated that vibrationally excited molecules were decomposing nitric oxide, viz. 

Protons attached to sp carbons are more acidic than protons attached to nonallylic sp carbons. Also, the inductive effect of a heteroatom further increases the acidity of an adjacent sp C-H bond, facilitating a-lithiation. The relative activating effect of heteroatoms is sulfur > oxygen > nitrogen. Thus, treatment of 2-ethoxy-l-(phenylthio)ethylene with t-BuLi results in exclusive lithiation at the phenylthio substituted carbon. ... 

Brookhart and co-workers [79-81] introduced catalysts based largely on chelating, nitrogen-based ligands that are active for the homopolymerization of ethylene and the copolymerization of ethylene with 1-olefins and polar comonomers (31). Ni, Co, Fe or Pd are used as late transition metals. The diimine ligands have big substituents to prevent 6-hydride elimination. Ni(II) or Pd(II) complexes form cations by combination with MAO and polymerize ethylene to highly branched polymers with molecular weights up to one million. The activities reach TON... 

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