The Distonic Hc+ (oh)och2 Radical Cation - a Stable Isomer of Ionized Methyl Formate

The distonic radical cation HC+ (OH)OCH2, an isomer of ionized methyl formate HC(O)OCH3+., has been generated from fragmentation of ionized isobutyl formate and ionized 2-methylbutyl formate and characterized by collisional activation (CA) and neutralization-reionization (NR) mass spectrometries. A mixture of both methyl formate and distonic radical cations has been detected following ionization of methyl formate. MO calculations at the UHF/6-31G** level showed that the distonic species is more stable its conventional isomer and that the energy difference between both isomers is essentially due to the difference of the O-H and C-H energies.