Ferraresi-Curotto Verónica, Echeverría Gustavo A, Piro Oscar E, Pis-Diez Reinaldo, González-Baró Ana C
CEQUINOR (CONICET, UNLP), CC 962, B1900AVV La Plata, Argentina; Depto. de Química, FACEyN-UNCa, Av. Belgrano 300, K4700AAP Catamarca, Argentina.
IFLP (CONICET, UNLP), CC 67, B1900AVV La Plata, Argentina.
Spectrochim Acta A Mol Biomol Spectrosc. 2015 Feb 25;137:692-700. doi: 10.1016/j.saa.2014.08.095. Epub 2014 Sep 6.
Five Schiff bases obtained from condensation of 4-methoxybenzohydrazide with related aldehydes, namely o-vanillin, vanillin, 5-bromovanillin, 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde were prepared. A detailed structural and spectroscopic study is reported. The crystal structures of four members of the family were determined and compared with one another. The hydrazones obtained from 5-chlorosalicylaldehyde and 5-bromosalicylaldehyde resulted to be isomorphic to each other. The solid-state structures are stabilized by intra-molecular O-H⋯N interactions in salicylaldehyde derivatives between the O-H moiety from the aldehyde and the hydrazone nitrogen atom. All crystals are further stabilized by inter-molecular H-bonds mediated by the crystallization water molecule. A comparative analysis between experimental and theoretical results is presented. The conformational space was searched and geometries were optimized both in gas phase and including solvent effects. The structure is predicted for the compound for which the crystal structure was not determined. Infrared and electronic spectra were measured and assigned with the help of data obtained from computational methods based on the Density Functional Theory.
制备了由4-甲氧基苯甲酰肼与相关醛（即邻香草醛、香草醛、5-溴香草醛、5-氯水杨醛和5-溴水杨醛）缩合得到的五种席夫碱。报道了详细的结构和光谱研究。测定了该家族四个成员的晶体结构并相互比较。由5-氯水杨醛和5-溴水杨醛得到的腙彼此同构。固态结构通过水杨醛衍生物中醛基的O-H部分与腙氮原子之间的分子内O-H⋯N相互作用得以稳定。所有晶体通过结晶水分子介导的分子间氢键进一步稳定。给出了实验结果与理论结果的对比分析。搜索了构象空间并在气相中以及包括溶剂效应的情况下优化了几何结构。预测了未测定晶体结构的化合物的结构。测量了红外光谱和电子光谱，并借助基于密度泛函理论的计算方法获得的数据进行了归属。
