Protonation of pyrrole and furan by H3O+ and NH4+ in the gas phase: A density functional theory study
- 化学化工－已发表论文 
Density functional theory and ab initio calculations have been used to determine structures and stabilities of the protonated aromatics species AH(+) and AH(2)(2+) (A=pyrrole, furan). Possible mechanisms and relative energetics for protonation of pyrrole and furan by H3O+ and AH(4)(+) in the gas phase have been explored. Calculations show that the C-alpha-protonated species was the most stable structure for AH(+), and the protonated AH(+) might accommodate the second proton to yield AH(2)(2+) if the free proton was available. The gas-phase H3O+ could protonate pyrrole and furan with significant exothermicity and almost without barrier. The proton transfer from AH(4)(+) to pyrrole and furan has a barrier ranging from 33.5 to 39.3 kJ/mol in the gas phase.