Solid State NMR Spectroscopy as a Precise Tool for Assigning the Tautomeric Form and Proton Position in the Intramolecular Bridges of <i>o</i>-Hydroxy Schiff Bases
作者:Magdalena Jaworska、Paweł B. Hrynczyszyn、Mirosław Wełniak、Andrzej Wojtczak、Katarzyna Nowicka、Grzegorz Krasiński、Hassan Kassassir、Włodzimierz Ciesielski、Marek J. Potrzebowski
DOI:10.1021/jp108104g
日期:2010.12.2
Two analogous Schiff bases, (S,E)-2-((1-hydroxy-3-methyl-1,1-diphenylbutan-2-ylimino)methyl)phenol (1) and (S,Z)-2-hydroxy-6-((1-hydroxy-3-methyl-1,1-diphenylbutan-2-ylamino)methylene)cyclohexa-2,4-dienone (2), exist in the solid state as phenol-imine and keto-amine tautomers, respectively. Their crystal structures were solved using the X-ray diffraction method. Sample 1 forms orthorhombic crystals
两个类似的席夫碱(S,E)-2-(((1-hydroxy-3-methyl-1,1-diphenylbutan-2-ylimino)methyl)phenol(1)和(S,Z)-2-hydroxy- 6-(((1-羟基-3-甲基-1,1-二苯基丁烷-2-基氨基)亚甲基)环己-2,4-二烯酮(2)以酚亚胺和酮胺互变异构体的形式固态存在,分别。使用X射线衍射法解析了它们的晶体结构。样品1种形式的空间群的斜方晶体P 2(1)2(1)2(1),而2形式的空间群的斜晶体P2(1)。在每个样品中,一个分子位于晶体结构的不对称单元中。一维和二维固态NMR技术被用于结构分配和用于检查13 C和15 Ñδ II的化学位移张量(CST)的值。NMR研究表明,跨度(Ω=δ 11 - δ 33)和歪斜(κ= 3(δ 22 - δ异。/Ω)是极其敏感的在席夫碱的互变异构形式改变理论NMR屏蔽的计算1和2的参数使用具有B3LYP官能团和6-311