Exploratory Photochemistry of Polyfluorinated 2-Naphthyl Azide

Abstract

The photochemistry of perfluoro-2-naphthylazide was examined. At low temperature (77 K), photolysis of the azide produces a persistent triplet nitrene which can be characterized by UV−vis and EPR spectroscopy. Photolysis at ambient temperature releases a short-lived (τ < 1 ns) singlet nitrene which can be captured in neat pyridine to form an isolable ylide. Thus the lifetime of singlet perfluoro-2-naphthylnitrene is more similar to that of phenylnitrene where τ = 0.01−0.1 ns than to perfluorophenylnitrene where τ has been deduced to be ≈20 ns. In the absence of concentrated pyridine, singlet perfluoro-2-naphthylnitrene forms a closed-shell azirine or ketenimine intermediate which forms intractable polymeric material.