Rotamerism and tautomerism in hydrazone derivatives of ethylacetoacetate: Spectroscopic features, Hammett relationships, and computational calculations
作者:Mohammad Reza Zamanloo、Rogayeh Salmanzadeh、Mehdi D. Esrafili、Bahareh Seyednoruziyan、Gholamhassan H. Imanzadeh、Habibollah Eskandari
DOI:10.1002/poc.4487
日期:——
structure–property correlation on the base of Hammett relationships. All of the hydrazone derivatives were found to equilibrate in acetone solution, and more of them existed in one rotameric form in solid state. The aryl substituents influence the intermolecular and intramolecular interactions differently, because the derivatives could be isolated as two distinct crystals only in a few members. Moreover, the RAHB concept
β-二羰基化合物的腙衍生物显示出完整的构型和构象变化,这使得它们被认为是揭示氢键在氢转移和转换中重要性的探针。3-氧代-丁酸乙酯衍生的腙通过 Japp-Klingemann 反应合成,并采用薄层色谱、红外 (IR)、紫外-可见 (UV-vis) 和 1 H 等色谱和光谱行为对其进行了表征13C核磁共振(NMR)技术。通过参考的光谱测量,确定并详细研究了两种可能的旋转异构体之间的构象异构化及其互变异构形式,并详细研究了共振辅助氢键 (RAHB) 概念。此外,使用获得的光谱数据评估取代基影响,并基于哈米特关系评估结构-性质相关性。发现所有腙衍生物在丙酮溶液中达到平衡,并且其中更多以一种旋转异构形式存在于固态。芳基取代基对分子间和分子内相互作用的影响不同,因为衍生物只能在少数成员中分离为两种不同的晶体。而且,RAHB 概念被发现可以在不同程度上稳定腙衍生物的构象异构体,从而导致不同的平衡常数。量子化学计算