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Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
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在极地介质中扭曲染色体的前所未有的超极化性
Alexander J-T Lou1, Stefania Righetto2, Christopher Barger1
1Department of Chemistry and the Materials Research Center , Northwestern University , 2145 Sheridan Road , Evanston , Illinois 60208 , United States.
Journal of the American Chemical Society
|June 19, 2018
概括
新的基于的染色体克服了聚合问题,在极性溶剂中保持强烈的光学非线性 (μβ). 通过将分子设计与性能联系起来,
科学领域:
- 材料科学
- 有机化学
- 非线性光学
背景情况:
- 扭曲分子内电荷转移 (TICT) 染色体具有很大的二次光学非线性 (μβ).
- 聚合在低极性介质中和极性驱动的电子结构变化在极性溶剂中限制了它们在电光 (E-O) 材料中的使用.
研究的目的:
- 在电光应用中开发基于的新型TICT染色体.
- 调查TICT染色体中interaryl扭转角度,电子结构和光学非线性之间的关系.
主要方法:
- 基于的TICT染色体的合成,其间扭转角度可变 (64-77°).
- 在非极性和极性溶剂中使用直流电场诱导的第二波生成 (EFISH) 来测量光学非线性 (μβ).
- 使用单晶X射线衍射和核Overhauser效应 (NOE) NMR进行结构性表征.
主要成果:
- 最扭曲的染色体B2TMC-2在CH2Cl2中表现出一个大的μβvec.
- 这种高的μβ值在极性DMF中保持 (μβvec = -20,370 × 10−48 esu),表明聚合减少和电子结构稳定.
- 由于扭转角度与增强的μβ相关,即使在中间扭转角度也会增加合的破坏.
结论:
- 在基于的TICT染色体中强制施加的扭转角度导致高光学非线性.
- 这些染色体在极性溶剂中表现出减少的聚合和稳定的性能,克服了E-O材料的关键限制.
- 这些发现为分子设计与宏观染色体性能提供了一条通路,用于先进的EO应用.
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