Photosciences and Photonics Section, Chemical Sciences and Technology Division , CSIR-National Institute for Interdisciplinary Science and Technology , Trivandrum 695 019 , India.
J Phys Chem B. 2019 Sep 26;123(38):8131-8139. doi: 10.1021/acs.jpcb.9b05430. Epub 2019 Sep 13.
The present work deals with the tight molecular packing of a bis-inclusion complex into rigid, 1D nanofibers. The bis-adamantane (AD) linked anthracene derivative AD-AN-AD readily formed the β-CD bis-inclusion complex, β-CD⊂AD-AN-AD⊃β-CD, which spontaneously assembled into a nanofiber network. The wide angle X-ray scattering pattern of the dried nanofibers indicated that these are highly crystalline in nature. Spectroscopic data of the aggregate are identical to those of the monomeric species, suggesting that the aggregate is not a regular H- or J-aggregate. We propose that the nanofibers constitute another example of the recently proposed class of "null" aggregates, based on the crystal structure and molecular packing in compound , which is the precursor of AD-AN-AD. The molecular packing in actually provides a strategy for the design of null aggregates. We propose that the nanofibers are formed from null aggregates of β-CD⊂AD-AN-AD⊃β-CD, wherein the anthracene moieties are twisted in the range of 60-72°, and this assignment is in line with the spectroscopic studies and NMR titration experiments.
本工作研究了双主体包合物紧密的分子堆积，形成了刚性的一维纳米纤维。双金刚烷（AD）连接的蒽衍生物 AD-AN-AD 很容易形成 β-CD 双主体包合物，β-CD⊂AD-AN-AD⊃β-CD，该包合物自发组装成纳米纤维网络。干燥纳米纤维的广角 X 射线散射图谱表明，这些纤维本质上具有高结晶性。聚集体的光谱数据与单体物种的光谱数据相同，表明聚集体不是规则的 H 或 J 聚集体。我们提出，根据化合物的晶体结构和分子堆积情况，这些纳米纤维构成了最近提出的“空”聚集体的另一个例子，化合物是 AD-AN-AD 的前体。在 中，分子堆积实际上为设计“空”聚集体提供了一种策略。我们提出，纳米纤维是由 β-CD⊂AD-AN-AD⊃β-CD 的空聚集体形成的，其中蒽部分在 60-72°范围内扭曲，这一分配与光谱研究和 NMR 滴定实验一致。
