Hydride abstraction of methylamine with Cu+(1S) in the gas phase: A density functional theory study

Mechanistic Insight into the Gas-Phase Reactions of Methylamine with Ground State Co+(3F) and Ni+(2D)

“…The binding energy of 59.7 kcal/mol for Ni + −MA obtained at the B3LYP/6-311++G(d,p) level (see Figure ) is in good agreement with the previous result at the B3LYP/6-311G(d,p) level (58.8 kcal/mol) . The calculated binding energies of the Co + −MA and Ni + −MA associations are also very close to the binding energy of 60.7 kcal/mol for the Cu + −MA association at the B3LYP/6-311++G(3df,2p) level . However, NBO analysis shows, quite different from the bonding situation of σ(Cu−N) (8.05% Cu(4s) + 91.95% N(2s 1 2p 5 )) in the Cu + −MA association, the Co + and Ni + associations are stabilized by the electron donation of the lone pair on the N atom into the metal 4s orbital (Δ E (2) : 43.25 and 47.45 kcal/mol for Co + −MA and Ni + −MA; see Table ).…”

“…However, only two isomers are found to exist stably in the reaction of MA with M + (M = Co, Ni), namely N-attached complex 1 and η 1 -methyl-H-attached complex 3 , as shown in Figures and . Complex 1 corresponds to the global minimum, and the existence of a lone pair on the N atom makes it the most suitable position for the attack of M + , characteristic of association involving amines and M + , for example, Na + , Mg + , − Co + , , Ni + , Cu + , − , and Ag + . This fact can be understood by considering the electron transfer that occurs from the N lone pair into the empty metal 4s orbital, and taking into account the reduction of repulsion caused by the 3d/4s hybridization at the metal center that moves electron density away from the M + −N axis.…”

“…Vibrational frequencies of all the optimized species were calculated at the same levels to identify the stationary points (minima or transition states) and to estimate the zero-point-energy (ZPE) corrections that are applied to all reported energies. Scaling factor for the ZPE was selected as 0.961. , To confirm the connection of transition states with the corresponding reactants and products for some key steps, intrinsic reaction coordinate (IRC) calculations , were performed to follow the reaction pathways. The values of ⟨S 2 ⟩ for all the calculated species were detected to evaluate if spin contamination can influence the quality of the results and found it is less than 5% (see Supporting Information Tables S1 and S2), suggesting that spin contamination is negligibly small in the calculated results.…”

Decomposition mechanism of methylamine to hydrogen cyanide on Pt(111): selectivity of the C–H, N–H and C–N bond scissions

“…Theoretical investigations are of great help for understanding the reaction mechanisms, especially for DFT investigations applied to reveal the microscopic adsorption structures, decomposition congurations, reaction pathways, and reaction kinetics and thermodynamics. [21][22][23] Lv et al 24 carried out DFT modelling to understand the initial CH 3 NH 2 decomposition on Ni(111) and Ni(100), and found that CH 3 NH 2 scission sequence took place with the order of C-H > N-H > C-N. Moreover, they investigated CH 3 NH 2 decomposition on Mo(100) 25,26 and Pd(111), 27 and the results showed that the most likely decomposition pathway was CH 28 and Co(111), 29 and found that the reaction mechanism of the hydrogenation pathway on both surfaces was HCN / CNH 2 + HCNH / CH 2 NH / CH 2 NH 2 + CH 2 NH / CH 3 NH 2 .…”

Formation of Organometallic Species, [M – H]+ Ions and Radical Cations upon Mass Spectrometric Fragmentation of Mercury–Crown Ether Complexes

“…Hydride abstraction is a known phenomenon in the chemistry of metal complexes. 22,23 In this paper it is demonstrated that the [M -H] + type of ions can be generated from mercury complexes by electrospray ionisation. further decomposition of this type of ion for some compounds (by using ion trap or fourier transform ion cyclotron resonance instruments, MS n mode, n > 2), could have practical applications (for example, for isomer differentiation).…”