Theoretical Investigation on the Intermolecular and Intramolecular Nucleophilic Substitution at Nitrogen

In an effort to explore the reactivity trends and the alpha-effect in the bimolecular-substitution reactions at formally neutral saturated nitrogen in gas-phase, more than 200 model intermolecular nucleophilic substitution reactions at nitrogen, SN2@(N), including a series of normal nucleophiles covering the Groups 14-17 elements (without an adjacent lone pair electrons) or alpha-nucleophiles (with adjacent lone pair electrons), will be theoretically investigated using ab initio MP2 and high-level Gaussian-2(+) methods. Meanwhile, some prototypic SN2@(N) reactions in nanotube, and intramolecular nucleophilic substitution at nitrogen, SNi@(N), will be also studied. The results will shed light to some similarities and differences between substitution reactions at nitrogen and at carbon. Moreover, the information from this study will help to better understand the origin of alpha-effect in the SN2 reactions, which has been a matter of debate for many years. Our calculated results may also be helpful for the further experimental studies.