Multiple Hydrogen Transfer during Metastable Time Window on Gas Phase Unimolecular Dissociation Using a Four Sector Tandem Mass Spectrometer

Abstract

In order to search for structural probe to estimate the intrinsic relative reactivity as intramolecular hydrogen donor/acceptor, electron ionized molecular ions for unsymmetrical bis(omega-phenylalkanoyl)imidazplidin(e)-2-(thi)ones have been subjected to metastable ion spectroscopy using a four sector tandem mass spectrometer. Competitive single/double/triple hydrogen transfers have been newly found by amide bond cleavage from acyl donors into nitrogen and/or nitrogen and/or oxygen atoms in imidazolidin(e)-2-(thi)one acceptors giving 2-mercapto/hydroxy-4,5-dihydroimidazolium ion. It is noteworthy that reactivity has been dramatically changed depend on difference of chain length in omega-phenylalkanoyl groups in such the unsymmetrical competitive channels.