TY - JOUR
T1 - The methylamine radical cation [CH3NH2]+˙ and its stable isomer the methylenammonium radical cation [CH2NH3]+˙
AU - Bouma, Willem J.
AU - Dawes, Judith M.
AU - Radom, Leo
PY - 1983
Y1 - 1983
N2 - The potential energy surface for the [CH5N]+˙ system has been investigated using ab initio molecular orbital calculations with large, polarization basis sets and incorporating valence‐electron correlation. Two [CH5N]+˙ isomers can be distinguished: the well known methylamine radical cation, [CH3NH2]+˙, and the less familiar methylenammonium radical cation, [CH2NH3]+˙. The latter is calculated to lie 8 kJ mol−1 lower in energy. A substantial barrier (176 kJ mol−1) is predicted for rearrangement of [CH2NH3]+˙ to [CH3NH2]+˙. In addition, a large barrier (202 kJ mol−1) is found for loss of a hydrogen radical from [CH2NH3]+˙ via direct N—H bond cleavage to give the aminomethyl cation [CH2NH2]+. These results are consistent with the existence of the methylenammonium ion [CH2NH3]+˙ as a stable observable species. The barrier to loss of a hydrogen radical from [CH3NH2]+˙ is calculated to be 140 kJ mol−1.
AB - The potential energy surface for the [CH5N]+˙ system has been investigated using ab initio molecular orbital calculations with large, polarization basis sets and incorporating valence‐electron correlation. Two [CH5N]+˙ isomers can be distinguished: the well known methylamine radical cation, [CH3NH2]+˙, and the less familiar methylenammonium radical cation, [CH2NH3]+˙. The latter is calculated to lie 8 kJ mol−1 lower in energy. A substantial barrier (176 kJ mol−1) is predicted for rearrangement of [CH2NH3]+˙ to [CH3NH2]+˙. In addition, a large barrier (202 kJ mol−1) is found for loss of a hydrogen radical from [CH2NH3]+˙ via direct N—H bond cleavage to give the aminomethyl cation [CH2NH2]+. These results are consistent with the existence of the methylenammonium ion [CH2NH3]+˙ as a stable observable species. The barrier to loss of a hydrogen radical from [CH3NH2]+˙ is calculated to be 140 kJ mol−1.
UR - http://www.scopus.com/inward/record.url?scp=84989040384&partnerID=8YFLogxK
U2 - 10.1002/oms.1210180104
DO - 10.1002/oms.1210180104
M3 - Article
AN - SCOPUS:84989040384
SN - 0030-493X
VL - 18
SP - 12
EP - 15
JO - Organic Mass Spectrometry
JF - Organic Mass Spectrometry
IS - 1
ER -