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对分子稳定性的区域化学影响:对1,4和1,5异位的三醇进行机械化学评估
Johnathan N Brantley1, Sai Sriharsha M Konda, Dmitrii E Makarov
1Department of Chemistry and Biochemistry, The University of Texas, Austin, Texas 78712, USA.
Journal of the American Chemical Society
|June 12, 2012
概括
超声波照射触发了含有1,4-和1,5-异位三醇的聚甲基烯酸) 链的循环逆转. 由于增强的机械可变性,1,5异构体的降解速度更快.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
背景情况:
- 1,2,3-三醇是聚合物合成中的多功能构建模块.
- 超声波诱导的反应为聚合物修饰提供了新的途径.
- 了解区域化学对聚合物降解的影响对于材料设计至关重要.
研究的目的:
- 为了研究用1,4-和1,5-异位1,2,3-triazoles功能化的聚甲基烯酸) 链的超声波诱导的循环逆转.
- 为了比较含有不同三醇区域异构体的聚合物的降解速率.
- 阐明异构体结构对机械可变性和反应动力学的影响.
主要方法:
- 通过"点击"化学合成聚甲基酸盐,使用1,4和1,5非替代的三醇.
- 聚合物溶液在酸中进行超声波处理.
- 谱分析 (例如,NMR,UV-Vis) 和化学标签,以监测循环逆转.
- 动力学研究以确定反应速率常数.
- 使用扩展的贝尔理论进行计算建模.
主要成果:
- 成功合成了聚甲基烯酸) 与1,4-和1,5-非替代的三醇.
- 超声波辐射诱导了两种聚合物类型中的三醇单元的正式循环逆转.
- 与1,4-异构体相比,1,5-异位的三醇异构体表现出比1,4-异构体快1.2倍的循环逆转速率常数.
- 计算研究支持了实验结果,将降解速率与机械可变性相关联.
结论:
- 三醇替代剂的区域化学显著影响了聚甲酸的超声波诱导降解动力学.
- 1,5-regioisomer 的机械可变性增加,在超声波下促进了更快的循环逆转.
- 这项研究提供了对含有三醇的聚合物的结构性质关系及其对机械刺激的反应的见解.
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