Mechanistic insight into the gas-phase reactions of methylamine with ground state Co+(3F) and Ni+(2D).
The gas-phase reaction mechanisms of methylamine (MA) with the ground-state Co(+)((3)F) and Ni(+)((2)D) are theoretically investigated using density functional theory at both the B3LYP/6-311++G(d,p) and B3LYP/6-311++G(3df,2p) levels. The reactions for hydride abstraction and dehydrogenation are analyzed in terms of the topology of potential energy surfaces (PESs). Co(+) and Ni(+) perform similar roles along the isomerization processes to the final products. Hydride abstraction takes place via the key species of metal cation-methyl-H intermediate, followed by a charge transfer process before the direct dissociation of CH(2)NH(2)(+)···MH (M = Co, Ni). The enthalpies of reaction, stability of metal cation-methyl-H species, and competition between different channels account for the sequence of the hydride abstraction products: CoH < NiH < CuH. The most competitive dehydrogenation route occurs through a stepwise reaction, consisting of initial C-H activation, amino-H shift, and direct dissociation of the precursor CH(2)NHM(+)···H(2). This theoretical work sheds new light on the experimental observations and provides fundamental understanding of the reaction mechanisms of amine prototype with late first-row transition metal cations.
College of Physics Science and Technology, China University of Petroleum, Dongying, Shandong 257061, People's Republic of China.
Xiaoqing
X
Lu
Shuxian
S
Wei
Wenyue
W
Guo
Chi-Man Lawrence
CM
Wu
D000588:Amines / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D002627:Chemistry, Physical / Q000379:methods*; D003035:Cobalt / Q000737:chemistry*; D003198:Computer Simulation; D005740:Gases; D006859:Hydrogen / Q000737:chemistry; D008027:Light; D008670:Metals / Q000737:chemistry; D008744:Methylamines / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D012984:Software
D000588:Amines; D002412:Cations; D005740:Gases; D008670:Metals; D008744:Methylamines; D003035:Cobalt; D009532:Nickel; D006859:Hydrogen; C027451:methylamine