Tautomerism in azo dyes: Border cases of azo and hydrazo tautomers as possible NMR reference compounds
作者:V. Deneva、A. Lyčka、S. Hristova、A. Crochet、K.M. Fromm、L. Antonov
DOI:10.1016/j.dyepig.2019.02.015
日期:2019.6
hydrazone tautomers. The tautomeric state is not substantially influenced by nitro group substitution in the phenyl ring. Consequently, the studied compounds can be used as model tautomers in the NMR evaluation of the tautomeric state in various azo dyes in solution. According to the crystallographic data (obtained by us or available in the literature) the conclusions about the tautomerism of the studied
为了满足互变异构偶氮染料研究中对NMR参考化合物的需求,衍生自3-甲基-1-苯基-4-(苯基二氮烯基)-1H-吡唑-5-胺和5-的两个系列偶氮染料甲基-2-苯基-4-(2-苯基肼基)-2,4-二氢-3H-吡唑-3-酮已通过分子光谱法(UV-Vis和NMR)和量子化学计算(M06- 2X / TZVP)。结果清楚地表明3-甲基-1-苯基-4-(苯基二氮烯基)-1H-吡唑-5-胺以纯偶氮互变异构形式存在,而5-甲基-2-苯基-4-(2-苯基肼基) -2,4-二氢-3H-吡唑-3-酮以互变异构体的形式存在。互变异构状态基本上不受苯环中硝基取代的影响。所以,所研究的化合物可在溶液中各种偶氮染料的互变异构状态的NMR NMR评价中用作模型互变异构体。根据晶体学数据(由我们获得或可从文献中获得),关于所研究化合物在溶液中的互变异构的结论在固态下也是有效的。