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首页> 外文期刊>Journal of chemical crystallography >Synthesis and X-ray Crystal Structure of 2 and 4-Trifluoromethyl Substituted Phenyl Semicarbazone and Thiosemicarbazone
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Synthesis and X-ray Crystal Structure of 2 and 4-Trifluoromethyl Substituted Phenyl Semicarbazone and Thiosemicarbazone

机译：2和4-三氟甲基取代的苯基氨基脲和硫代蓟虫肼的合成和X射线晶体结构

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摘要

NMR and single crystal X-ray structure data for four structurally similar semicarbazones and thiosemicarbazones were compared. In solution, proton NMR showed considerable variation in their chemical shift values especially for the NH2 protons. In the case of the semicarbazones this peak appeared as a broad singlet with an integration ratio of two while for the thiosemicarbazones the amino group showed two distinct singlets with marked chemical shift differences. This is attributed to the differences in the canonical forms of the thiosemicarbazone amino group and the semicarbazone analogue. Additionally, we provide evidence that the 2-trifluoromethyl phenyl substituted semicarbazone (2) formed an intermolecular hydrogen bond with one of the hydrogens of the NH2 group while this was totally absent in the thiosemicarbazone. We explain this by the restricted rotation of the CN bond in the thiosemicarbazone due to its double bond character compared to the less restricted rotation in semicarbazone compound.
机译：比较了四种结构类似的胚素和硫代喹脱石的NMR和单晶X射线结构数据。在溶液中，质子NMR在其化学变换值中表明其尤其是NH 2质子的相当大的变化。在缩氨酸的情况下，该峰值出现为阔单的单线术，整合比为两种，而对于硫代蓟虫毒素而言，氨基显示出两个具有明显的化学变化差异的不同单曲。这归因于硫代喹甲腺苷氨基和胚肼类似物的规范形式的差异。另外，我们提供了二三氟甲基苯基取代的氨基脲（2）与NH 2组的氢氢氢键形成分子间氢键，同时在硫代噻虫中缺席。通过其双键特征，通过其双键性的缩小旋转在半咔哒萘化合物的较少旋转，我们通过限制硫代萘酮的限制旋转来解释这一点。

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