Reversible Interlayer Sliding and Conductivity Changes in Adaptive Tetrathiafulvalene-Based Covalent Organic Frameworks
Reversible Interlayer Sliding and Conductivity Changes in Adaptive Tetrathiafulvalene-Based Covalent Organic Frameworks
复制标题
自适应四硫富瓦烯共价有机框架中的可逆层间滑动和电导率变化
DOI：
10.1021/acsami.0c03280
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发表时间：
2020-04-22
影响因子：
9.5
通讯作者：
Liu, Yi
中科院分区：
文献类型：
--
作者：
Cai, Songliang;Sun, Bing;Liu, Yi
有序层间堆积是二维共价有机框架（2D COF）中固有的，并对COF的光电性能有很强的影响。可逆层间滑动，对应于二维层沿着其基面的剪切，是一个有吸引力的结构和性质的动态控制，但它仍然是在二维COF领域的探索。在此，我们证明了可逆的层间滑动可以实现在亚胺连接的四硫富瓦烯（TTF）为基础的COF TTF-DMTA。溶剂处理诱导结晶相之间的变化，提出了阶梯状的sql网络结构和一个轻微的滑动重叠的sql网络结构。溶剂化诱导的结晶度变化与可逆的光谱和电导率变化密切相关，如取向COF薄膜所示。相比之下，在相关TTF-TA COF中没有观察到可逆转换，其与TTF-DMTA的不同之处在于亚苯基连接基上不存在甲氧基。这项工作代表了第一个2D COF的例子，其中日食和楼梯状聚合状态可互换地通过层间滑动，一个未知的结构特征，可以使应用程序，如化学电阻传感器访问。
Ordered interlayer stacking is intrinsic in two-dimensional covalent organic frameworks (2D COFs) and has strong implications on COF's optoelectronic properties. Reversible interlayer sliding, corresponding to shearing of 2D layers along their basal plane, is an appealing dynamic control of both structures and properties, yet it remains unexplored in the 2D COF field. Herein, we demonstrate that the reversible interlayer sliding can be realized in an imine-linked tetrathiafulvalene (TTF)-based COF TTF-DMTA. The solvent treatment induces crystalline phase changes between the proposed staircase-like sql net structure and a slightly slipped eclipsed sql net structure. The solvation-induced crystallinity changes correlate well with reversible spectroscopic and electrical conductivity changes as demonstrated in oriented COF thin films. In contrast, no reversible switching is observed in a related TTF-TA COF, which differs from TTF-DMTA in terms of the absence of methoxy groups on the phenylene linkers. This work represents the first 2D COF example of which eclipsed and staircase-like aggregated states are interchangeably accessed via interlayer sliding, an uncharted structural feature that may enable applications such as chemiresistive sensors.