含氟β-二酮类化合物在质子溶剂中光稳定机理的研究

A STUDY ON THE PHOTOSTABILIZING MECHANISM OF FLUORO-CONTAINING β-DIKETONE IN PROTONIC SOLVENT

本工作利用吸收光谱及核磁共振氢谱的方法对两种含—CF_3基的β-二酮类化合物在质子溶剂中引起分子内氢键的破坏,缩醛化的发生及其动力学等进行了研究。工作探讨了光照使缩醛化产物回复至原有的分子内氢键结构以及回复后体系在暗场下继续进行缩醛化的过程,虽然光照使缩醛化产物破坏的原因尚待进一步研究,但这类含有—CF_3基的β-二酮类化合物在光照条件下能回复到含有分子内氢键的体系,这一特性可使这类化合物用作一种能在质子溶剂中应用的光稳定剂。其光稳定能力在本工作中已被证实。

The destruction of intramolecular hydrogen bond, hemiacetal formation and their kinetics for fluoro-containing β-diketone compounds in protonic solution have been studied by absorption and 'H NMR spectroscopy. The processes of photo-irradiation which induces the hemiacetal going back to the original intramolecular hydrogen bond structure and the hemiacetal formation for the system after irradiation in the dark have also been investigated. Although the reason of hemiacetal destruction by irradiation is not clear yet, this kind of β-diketone with -CF3 group which will return to intramolecular hydrogen bond under irradiation can be used as photostabilizer in the protonic solvents. The photostability of these compounds has been confirmed in this work.