A FLOW-TUBE STUDY OF ISOMERS OF C2H4CL- THE CHLORONIUM AND 1-CHLOROETHYL CATIONS( )

Reactions of the 1-chloroethyl and the chloronium cations with ammonia were observed in the gas phase at room temperature in helium at 0.36 Torr using the selected-ion flow tube (SIFT) technique. The 1-chloroet hyl cation in its reaction with ammonia only undergoes proton transfer The chloronium ion reacts with ammonia by association and the elimina tion of HCl. Association, which has not been observed in previous ICR studies, is the predominant channel. A value of 556 kJ mol(-1) was cal culated at MP4SDTQ(fc)16-31l++G(2df,p)//MP2(full)/6-311(d,p) for the s tandard enthalpy of formation of the adduct of the chloronium ion with ammonia, The adduct ion was observed to react further with NH3 to eli minate NH2Cl and NH2CH2Cl. A mechanism is proposed for the overall seq uential reaction of the chloronium ion with two molecules of ammonia.