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双取代哌啶基二硫化物的动态~1H NMR谱的研究表明,分子内哌啶环的翻转活化自由能较哌啶有显著增加,△G值为71.43±0.25—73.27±0.46kJ·mol~(-1)同时观察到双哌啶基二硫化物分子内哌啶环的3、4、5-位所在平面的翻转,比1、2、6-位所在平面约快四倍,△G值低3.62kJ·mol~(-1);这充分显示了分子中N原子上带有较大基团的影响.比较双哌啶基二硫化物与相应三硫化物的环翻转能垒,也显示出空间障碍的影响.
The dynamic ~ 1H NMR spectra of disubstituted piperidinyl disulfides showed that the free activation energies of the piperidine ring were significantly increased compared with that of piperidine. The △ G values were 71.43 ± 0.25-73.27 ± 0.46 kJ · mol ~ (-1) At the same time, the inversion of the 3,4,5-position of the piperidine ring in the dipiperidyl disulfide molecule was observed, about four times faster than that of the 1,2,6-position. The △ G value Low 3.62kJ · mol ~ (-1), which fully shows the effect of larger groups on the N atom in the molecule.Comparing the ring-reversal barrier of dipiperidyl disulfide with the corresponding trisulfide also shows Out of space obstacles.