A Comparative Theoretical Study of the Reactivities of the Al and Cu Ions Toward Methylamine and Dimethylamine

作者：Liu Peng; Liu Jianqiang; Zhang Dongju^*; Zhang Changqiao

来源：International Journal of Quantum Chemistry, 2010, 110(9): 1583-1593.

DOI：10.1002/qua.22314

• aluminum ion
• copper ion
• methylamine
• dimethylamine
• reaction mechanism
• DFT

A very recent laser ablation-molecular beam experiment shows that an Al ion can react with a single methylamine (MA, CH2NH2) or dimethylamine (DMA, (CH3)(2)NH) molecule to form a 1:1 ion molecule complex Al [CH3NH2] or Al [(CH3)(2)NH)], whereas a dehydrogenated complex ion Cu [CH3N] or Cu [C2H5N] is detected, respectively, in the similar reaction for a Cu ion. Here, we show a comparative density functional theory study for the reactivities of the Al and Cu ions toward MA and DMA to reveal the intrinsic mechanism. It is found that the interactions of the Al ion with MA and DMA are mostly electrostatic, leading to the direct ion molecule complexes, Al -NH2CH3 and Al -NH(CH3)(2), in contrast to the non-negligible covalent character in the corresponding Cu -containing complexes, Cu -NH2CH3 and Cu- NH(CH3)(2). The general dehydrogenation mechanism for MA and DMA promoted by the Cu ion has been shown, and the preponderant structures contributing to the mass spectra of the product ions Cu [CH3N] and Cu [C2H5N] are rationalized as Cu -NHCH2 and Cu -N(CH2)(CH3). The presumed dehydrogenation reactions are also discussed for the Al -containing systems. However, the involved barriers are found to be too high to be overcome at low energy conditions. These results have rationalized all the experimental observations well.

• 出版日期2010-8-5
• 单位山东大学