形状持久的分子构建块的灵活性由p-烯和乙烯单元组成
Gunnar Jeschke1, Muhammad Sajid, Miriam Schulte
1Laboratory for Physical Chemistry, ETH Zürich, 8093 Zürich, Switzerland. gunnar.jeschke@phys.chem.ethz.ch
Journal of the American Chemical Society
|July 2, 2010
概括
研究人员使用脉冲电子磁共振 (EPR) 研究纳米分子的骨干灵活性. 带有乙烯和p-烯单元的寡合物在灵活性上有轻微的差异,受溶剂性质的影响.
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
- 纳米技术 纳米技术
背景情况:
- 乙烯和p-烯单位是纳米分子的关键组成部分.
- 脊柱的灵活性极大地影响了分子形状,机械和电子性质.
- 端到端的距离分布是骨干灵活性的特征.
研究的目的:
- 开发一个一致的粗粒度模型,用于骨干灵活性在oligo (p-phenyleneethynylene) 和oligo (p-phenylenebutadiynylene) 中.
- 研究脊柱序列,长度和旋转标签对灵活性的影响.
- 为了比较Oligo (p-phenyleneethynylene) 和Oligo (p-phenylenebutadiynylene) 的灵活性.
主要方法:
- 使用极性标记合成四个具有不同p-phenylene/ethynylene序列和旋转标签的寡合体集.
- 脉冲电子磁共振 (EPR) 距离测量以确定端到端距离分布.
- 粗粒度建模和与形链和原子模拟进行比较.
主要成果:
- 获得了一种一致的粗粒度模型,用于骨干灵活性.
- 奥利戈 (p-phenylenebutadiynylene) 的灵活性略高于奥利戈 (p-phenyleneethynylene) 的灵活性.
- 端到端距离分布显示依赖于溶剂的玻璃过渡温度.
结论:
- 波细分链模型准确地描述了骨干灵活性.
- 预测在298K的持久度为 (13.8 ± 1.5) 纳米对于聚乙烯和 (11.8 ± 1.5) 纳米对于聚乙烯.
- 灵活性在定量上与在广泛的温度范围内的和曲模型相一致.
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