Synthesis and X-ray Crystal Structure of 2 and 4-Trifluoromethyl Substituted Phenyl Semicarbazone and Thiosemicarbazone
作者:T. K. Venkatachalam、Paul V. Bernhardt、Gregory K. Pierens、David C. Reutens
DOI:10.1007/s10870-017-0677-z
日期:2017.4
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
摘要比较了四种结构相似的缩氨基脲和缩氨基硫脲的核磁共振和单晶 X 射线结构数据。在溶液中,质子 NMR 显示它们的化学位移值有相当大的变化,特别是对于 NH2 质子。在缩氨基脲的情况下,该峰表现为积分比为 2 的宽单峰,而对于缩氨基硫脲,氨基显示两个不同的单峰,具有显着的化学位移差异。这归因于缩氨基硫脲氨基和缩氨基脲类似物的规范形式的差异。此外,我们提供的证据表明,2-三氟甲基苯基取代的缩氨基脲 (2) 与 NH2 基团的一个氢形成分子间氢键,而这在缩氨基硫脲中完全不存在。