The syntheses of the first examples of selenoparabanic acid derivatives (dialkylimidazolidine-2-selone-4,5-dione, 3eR R = Me, Et, Bu) are presented along with the X-ray crystal structure determination of 3eEt. To gain an insight in the properties of parabanic acid derivatives on the basis of their electronic structures, we report the results of comparative hybrid-DFT calculations performed on parabanic, thioparabanic, and selenoparabanic acids (3aH, 3bH, and 3eH) and on their N,N' -dimethyl derivatives (3aMe, 3bMe, and 3eMe). Calculations show that the different nature of the frontier orbitals of 3aR compared to those of 3bR and 3eR, might account for the different reactivities of these compounds. Moreover, the weak donor character of 3bR and 3eR towards molecular di-iodine, estimated by FT-Raman measurements is in agreement with the calculated NBO-charge distribution.Key words: selenation, selenoparabanic derivatives, crystal structure, DFT calculations.
首次合成了硒代对苯二甲酸衍生物的第一个例子(双烷基咪唑烷二硒酮-4,5-二酮,3eR R = Me, Et, Bu),并展示了3eEt的X射线晶体结构测定结果。为了深入了解对苯二甲酸衍生物的性质基础上的电子结构,我们报告了对对苯二甲酸、硫代对苯二甲酸和硒代对苯二甲酸(3aH、3bH和3eH)以及它们的N,N' -二甲基衍生物(3aMe、3bMe和3eMe)进行的比较混合-DFT计算的结果。计算结果表明,与3bR和3eR的前线轨道相比,3aR的前线轨道的不同性质可能解释了这些化合物的不同反应性。此外,通过FT-Raman测量估计的3bR和3eR对分子二碘的弱给体特性与计算的NBO-电荷分布一致。
关键词:硒化、硒代对苯二甲酸衍生物、晶体结构、DFT计算。