
%0 Journal Article
%A Crow, WD 
%A Khan, AN 
%A Paddon-Row, MN 
%A Sutherland, DS 
%T The C<sub>6</sub>H<sub>5</sub>N energy surface. V. Isomerization of pyridylcarbenes to phenylnitrene&#8211;a <sup>13</sup>C-labelling study
%J Australian Journal of Chemistry
%D 1975/08/01
%V 28
%N 8
%P 1763-1773
%K 
%R https://doi.org/10.1071/CH9751763
%U https://www.publish.csiro.au/paper/CH9751763 
%X 5-(2-, 3- and 4-Pyridyl)tetrazoles have been synthesized with a 13C- label at the 5-position and pyrolysed at 500-600° under reduced pressure to generate the corresponding pyridylcarbenes. Analysis of the aniline which results from their isomerization to phenylnitrene has been carried out by pulsed Fourier transform 13C N.M.R. The results show that, although both the cycloperambulatory (CP) and insertion-extrusion (IEP) mechanisms are operative, the latter predominates to a very great extent. As in the case of tolylcarbenes, this result is ascribed to a kinetic effect, i.e. the (largely irreversible) nitrogen extrusion step which generates phenylnitrene. The preferred modes of isomerization in the pyridylcarbenes are discussed. 
