Phosphinylhydrazyls R2NNP(O)L2, an ESR Study. Influence of the Captodative Effect on the Three-Electron NN ? Bond

Article abstract of DOI:10.1021/jo00353a013

1,1-Dimethyl-2-phosphinylhydrazyls and 1-tert-butyl-2-phosphinylhydrazyls have been generated from the corresponding hydrazines.Their radical structures have been assigned on the basis of their ESR spectral parameters.In contrast with the behavior of trialkylhydrazyls or 1,2-dialkylhydrazyls it has been shown that in the phosphinylhydrazyls the larger nitrogen splitting is due to the tervalent nitrogen.Phosphinylhydrazyls have been shown to exist in equilibrium with their dimer form.The radical Me2NNP(O)(OEt)2 is particularly persistent, and the free activation energy for the rotation about the NN bond has been measured (ΔG<*>=9.8 +/- 0.5 mol)