STRUCTURE OF [C8H7](-TRANSFER REACTIONS IN 3-PHENYL-1-BUTYN-3-OL BY MS() AND INTRAMOLECULAR PROTON)MS TECHNIQUE/

The electron impact mass spectrum (EIMS) of 3-phenyl-1-butyn-3-ol was reported in this paper. Collision-induced dissociation (CID) was used to study the gas phase ion structure of [C8H7](+) formed by the fragme ntation of ionized 3-phenyl-1-butyn-3-ol, and that it has the same str ucture as m/z 103 ions generated by cinnamic acid and alpha-methylstyr ene. Deuterium labelling, metastable ion (MI) and CID experimental res ults indicate the formation of m/z 103 ion resulting from molecular io n of 3-phenyl-1-butyn-3-ol, which is a stepwise procedure via twice pr oton transfers, rather than concerted process during the successive el imination of methyl radical and neutral carbon monoxide accompanying h ydrogen transfer. Moreover, in order to rationalized these fragmentati on processes, the bimolecular proton bound complex between benzyne and acetylene intermediate has been proposed.