结合聚合物中的激发性能量迁移:链间形态的关键作用
Zhongjian Hu1, Takuji Adachi, Ryan Haws
1Center for Nano and Molecular Science and Technology, Department of Chemistry, University of Texas , Austin, Texas 78712, United States.
Journal of the American Chemical Society
|October 1, 2014
概括
结合聚合物形态决定了激发性能量迁移. 高排序的聚合物允许长距离迁移,而无序或重的侧链抑制了这一过程,影响了能量传输效率.
科学领域:
- 材料科学 材料科学 材料科学
- 频谱学是一种光谱学.
- 聚合物化学 聚合物化学
背景情况:
- 刺激性能量迁移对于有机电子设备至关重要.
- 了解形态学对合聚合物 (CPs) 能量转移的影响是关键.
研究的目的:
- 调查链间形态如何影响CP的激发性能量迁移.
- 为了将聚合物结构与能量传输途径相关联.
主要方法:
- 单个CP链和聚合物的单分子光谱学.
- 溶剂蒸汽回火以控制链间形态.
- 单聚合物光谱学. 单聚合物光谱学.
- 结构模拟.结构模拟.
主要成果:
- 高排序的rr-P3HT可以实现远程链间的能量迁移.
- 无序的rra-P3HT阻碍了链间的能量迁移.
- 在POMeOPT中,庞大的侧链完全抑制了链际能量迁移.
- 侧链诱导的扭曲,不仅仅是距离,也会影响链间合.
- 链内合与链内传输相竞争.
结论:
- 链间形态是CP中激发性能量迁移效率的关键决定因素.
- 聚合物设计,包括侧链工程,可以调整能量传输路径.
- 顺序包装促进了高效的能量迁移,这对于光电子应用至关重要.
相关概念视频
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.4K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.4K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.1K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.1K
01:17Thermal Electrocyclic Reactions: Stereochemistry
1.6K
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
1.6K
01:37Energy to Drive Translocation
2.0K
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
2.0K
01:21Energy Associated With a Charge Distribution
2.0K
The work done to bring a charge through a distance r is given by the potential difference between the initial and the final position. To assemble a collection of point charges, the total work done can be expressed in terms of the product of each pair of charges divided by their separation distance, defined with respect to a suitable origin. Solving this expression gives the energy stored in a point charge distribution.
2.0K
01:14Molecular Spectroscopy: Absorption and Emission
4.1K
Molecules possess discrete energy levels called quantum states. Unlike atoms, which have simpler energy levels, molecules possess additional rotational and vibrational energy levels. Each energy level is separated by an energy gap, with the gaps between adjacent electronic, vibrational, and rotational levels varying significantly. The three types of energy levels in a diatomic molecule are shown in Figure 1.
4.1K