Complete vibrational assignments have been performed for free base, cationic, and hydrochloride species derived from antiviral adamantadine by a combination of hybrid B3LYP with the 6‐31G* and 6‐311++G** basis sets and the scaled quantum force field methodology. Normal internal coordinates and scaling factors were used to obtain the harmonic force fields and scaled force constants of three species in gas phase and in aqueous solution. Bond lengths and angles of cationic and hydrochloride species show very good concordances with experimental amantadinium azide. The cationic species reveals a higher solvation energy value compared with antiviral agents; however, brincidofovir, the antiviral used for Ebola disease, presents a higher reactivity in contrast to adamantadine. A positive value of Mulliken charge on N1 of hydrochloride species in solution could justify the ionic character of the H29···Cl30 bond as it is possible to observe by bond order and atoms in molecules calculations. The hydrochloride species is the most reactive in both media, while the cationic species is the least reactive. High electrophilicity and nucleophilicity indices of cationic species in both media justify its higher hydration. Good concordances were observed between experimental and predicted ¹H and ¹³C NMR and electronic spectra. In solution, the three species are present as demonstrated by the experimental ultraviolet‐visible spectrum of hydrochloride amantadine.

中文翻译：

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抗病毒金刚烷胺衍生物种的正常内部坐标，力场和振动研究

通过将杂化B3LYP与6-31G *和6-311 ++ G **基组和比例量子力场方法相结合，对源自抗病毒金刚烷胺的游离碱，阳离子和盐酸盐类化合物进行了完整的振动分配。使用正常的内部坐标和比例因子来获得气相和水溶液中三种物质的谐波力场和比例力常数。阳离子和盐酸盐物种的键长和角度与实验性金刚烷叠氮化物显示出非常好的一致性。与抗病毒剂相比，阳离子物种显示出更高的溶剂化能值。然而，与金刚烷胺相比，用于埃博拉病的抗病毒药物brincidofovir具有更高的反应性。溶液中盐酸物种的N1上的Mulliken电荷为正值可以证明H29···Cl30键的离子性质是正当的，因为可以通过键序和分子计算观察到。在两种介质中，盐酸盐类的反应性最高，而阳离子类的反应性最低。两种介质中阳离子物种的高亲电性和亲核性指数证明其较高的水合性。实验和预测之间观察到良好的一致性 两种介质中阳离子物种的高亲电性和亲核性指数证明其较高的水合性。实验和预测之间观察到良好的一致性 两种介质中阳离子物种的高亲电性和亲核性指数证明其较高的水合性。实验和预测之间观察到良好的一致性¹ H和¹³ C NMR和电子光谱。在溶液中，通过盐酸金刚烷胺的紫外可见光谱实验证明了存在的三种物质。