(Chemical Equation Presented) Stable relations: Reaction of phenylazide with a phosphine borane derivative gives rise to an intramolecularly stabilized phosphazide 1 (R = iPr, R′ = mesityl) that undergoes an unprecedented photoisomerization process associated with a change from an N α→B to an Nβ→B interaction (see scheme). The generality and possible reversibility of such phenomena are demonstrated with the related phosphazine adduct 2
