Oblique Packing and Tunable Excitonic Coupling in DNA-Templated Squaraine Rotaxane Dimer Aggregates
Oblique Packing and Tunable Excitonic Coupling in DNA-Templated Squaraine Rotaxane Dimer Aggregates
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DOI：
10.1002/cptc.202200039
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发表时间：
2022-05-02
期刊：
影响因子：
3.7
通讯作者：
Pensack, Ryan D.
中科院分区：
文献类型：
--
作者：
Barclay, Matthew S.;Wilson, Christopher K.;Pensack, Ryan D.
当分子聚集到其激发态形成离域激子时，其空间排列或堆积可以通过模板粗略地控制，通过化学取代来精细控制；然而，在中等长度尺度上控制它们的堆积仍然存在挑战。在这里，我们使用一种基于机械互锁分子的方法来促进一系列三个方形轮烷二聚体中难以捉摸的倾斜堆积排列。我们用DNA作为方形轮烷二聚体的模板，并在其吸收光谱中观察到两个强度接近的激子分裂带--这是倾斜堆积的明显特征，并通过实验结果的理论建模进行了验证。通过对轮烷的大循环进行氟化，证明了对填充的额外精细控制，这促进了更紧密的填充和更强的激子相互作用。
When molecules are aggregated such that their excited states form delocalized excitons, their spatial arrangement, or packing, can be coarsely controlled by templating and finely controlled by chemical substitution; however, challenges remain in controlling their packing on intermediate length scales. Here, we use an approach based on mechanically interlocked molecules to promote an elusive oblique packing arrangement in a series of three squaraine rotaxane dimers. We template the squaraine rotaxane dimers using DNA and observe two excitonically split bands of near-equal intensity in their absorption spectra - a distinct signature of oblique packing, validated by theoretical modeling of the experimental results. Additional fine control of packing is demonstrated by fluorinating the macrocycle of the rotaxane, which promotes denser packing and stronger excitonic interactions.