The Question of Tautomerism of Alkylnitrile and Isonitrile Cations

Article abstract of DOI:10.1002/oms.1210171005

The isomeric pairs^+. and ^+. and ^+. and ^+. have been established as stable, noninterconverting structures.The conclusion derives from studies of collision induced decomposition spectra.The same conclusion pertains for the ions ^+. and ^+., and for +., ^+. and HNCCHCHCNH>^+..The energy barrier of a <1,3>-hydrogen shift, a possible isomerization mechanism, is determined to be at least 163kJ mol^-1 for the ^+. and ^+. pair, and the barrier may be as high as 318kJ*mol^-1.The C3H5N and C4H4N2 radical cations decompose before they can be activated with 318 kJ mol^-1 of internal energy.