Kinetic differentiation between non-specific hydrogen rearrangement and hydrogen scrambling in phenyl n-propyl ether. A field ionisation and collisional activation study

Abstract

The different kinetics of non-specific hydrogen rearrangements on the one hand, and hydrogen scrambling processes on the other, can be used to distinguish between these two processes as demonstrated for C 3H 6 elimination from the phenyl n-propyl ether molecular ion. The kinetic results support the conclusion, reached previously in an electron-impact study [2], that the rearrangement in phenyl alkyl ethers is a non-specific hydrogen transfer involving transition states of different ring sizes. Collisional activation spectra, reported in this study, show that the [C 6H 6O] +− ion formed by this rearrangement has the structure of the ionised phenol, which suggests that the hydrogen atoms from all positions of the side chain are transferred to the oxygen and not to the ortho-position of the phenyl ring.