• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >The Selective OH Radical Oxidation of Sorbitylfurfural: A Combined Experimental and Theoretical Study
【24h】

The Selective OH Radical Oxidation of Sorbitylfurfural: A Combined Experimental and Theoretical Study

机译：山梨糖基糠醛的选择性OH自由基氧化：组合的实验和理论研究。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Sorbitylfurfural (Furalglucitol), widely used in the cosmetic industry as antioxidant and antiinflammatory agent, reacts with hydroxyl radical in neutral aqueous solution with a rate constant almost at the diffusional limit, k_1 = 7.3 * 10~9 M~(-1) s~(-1). Despite the unselective character of the OH radical, addition to the 5'-position in the furanic ring seems to provide the dominant path. The consequent allylic radical undergoes the cleavage of the C-O bond (k_2 = 1.7 * 10~6 s`(-1)) in β position to form a pseudo-seven-atom ring via a hydrogen bond between the attacking OH group and the furanic oxygen. A 1,6 H-shift between the two oxygen atoms (k_3 = 1.4 * 10~5 s~(-1)) then precedes a disproportionation reaction which leads to the final products (k_4 = 2.0 * 10~7 M~(-1) s~(-1)). The proposed mechanism is based on the UV-vis spectra of intermediates and final products obtained after pulse and gamma radiolysis, on nonlinear kinetic fittings of absorbance versus time curves, on quantum-mechanical calculations of electronic transitions and reaction enthalpies. The two most important final products have been isolated and characterized as sorbityl-but-2-enal derivatives by LC-MS.
机译：山梨糖基糠醛（果糖醇），在化妆品工业中广泛用作抗氧化剂和消炎剂，与中性水溶液中的羟基自由基反应，速率常数几乎在扩散极限处，k_1 = 7.3 * 10〜9 M〜（-1）s〜 （-1）。尽管OH自由基具有非选择性特征，但在呋喃环中的5'-位看来似乎提供了主要途径。随后的烯丙基自由基在进攻的OH基团与呋喃基之间通过氢键在β位置经历CO键的裂解（k_2 = 1.7 * 10〜6 s`（-1））以形成假七原子环。氧。然后在两个氧原子之间发生1,6 H位移（k_3 = 1.4 * 10〜5 s〜（-1）），然后发生歧化反应，最终产生最终产物（k_4 = 2.0 * 10〜7 M〜（- 1）s〜（-1））。所提出的机理是基于脉冲和伽马射线辐解后获得的中间体和最终产物的紫外可见光谱，吸光度与时间曲线的非线性动力学拟合，电子跃迁和反应焓的量子力学计算。 LC-MS已分离出两个最重要的最终产物，并将其表征为山梨醇-丁-2-烯醛衍生物。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号