Solid state structure and properties of phenyl diketopyrrolopyrrole derivatives
Solid state structure and properties of phenyl diketopyrrolopyrrole derivatives
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DOI：
10.1039/d1ce00039j
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发表时间：
2021-02-28
期刊：
影响因子：
3.1
通讯作者：
Amabilino, David B.
中科院分区：
文献类型：
--
作者：
Humphreys, Joshua;Pop, Flavia;Amabilino, David B.
二酮基吡咯并吡咯衍生物（DPPs）的固态超分子相互作用及其与薄膜光学性质的相关性由于这些材料在有机电子学中的应用而引起人们的特别兴趣。在这项研究中，我们报告的单晶X-射线结构的几个苯基DPP衍生物，含有4-甲氧基苯基，4-羟基苯基和4-（（四氢-2H-吡喃-2-基）氧基）苯基芳基单元，并显示如何微妙的变化，在侧或端位置的发色团的取代基链可以导致非常不同的包装。他们相比，他们的苯基对应物，探索如何的烷基链和芳基单元的性质的影响，已在固体和溶液状态下测量的光学性质。重要的是，对于三个家庭的N-取代的化合物的研究，结构被改变的分子的构象，显然是占主导地位的晶体堆积效应，边到面的相互作用是有利的，而不是π堆叠，只有一个化合物显示出平坦的形式，促进分子间的芳香区域之间的接触。因此，DPP晶体中DPP和苯基单元之间的扭曲可能是由边-面相互作用（而不是N-取代基和连接到芳环的质子之间的空间相互作用）引起的，这可能在更扩展的结构中被克服。氢键占主导地位的包装，以产生链的DPP单元的苯酚衍生物。远距离大基团确实影响核心构象。作为薄膜的材料的发射由材料的堆积中的局部效应主导，所述局部效应对于每种情况是独特的，因为结构彼此不同。电荷迁移率（根据晶体结构计算）由于扭曲构象和大位移而不受欢迎，但有时高发射和大斯托克斯位移可能使材料对其他用途感兴趣，例如发光体。
The solid state supramolecular interactions of diketopyrrolopyrrole derivatives (DPPs) and their correlation with thin film optical properties are of particular interest because of the applications of these materials in organic electronics. In this study, we report the single crystal X-ray structures of several phenyl DPP derivatives, containing 4-methoxyphenyl, 4-hydroxyphenyl and 4-((tetrahydro-2H-pyran-2-yl)oxy)phenyl aryl units, and show how subtle changes in the substituent chains at side or end positions of the chromophore can lead to very different packing. They are compared to their phenyl counterpart to explore how the nature of both the alkyl chain and the aryl unit influence the optical properties that have been measured in solid and solution states. Importantly, for the three families of N-substituted compounds studied, the structures are changed by the conformation of the molecules and are apparently dominated by crystal packing effects where edge-to-face interactions are favoured rather than pi stacking, with only one of the compounds showing a flat form, promoted by intermolecular contacts between the aromatic regions. It is therefore possible that the twist between DPP and phenyl units in crystals of DPPs results from edge-to-face interactions (rather than steric interactions between the N-substituent and the protons attached to the aromatic ring) that might be overcome in more extended structures. Hydrogen bonding dominates the packing to generate chains of DPP units for phenol derivatives. Remote bulky groups do affect the core conformation. The emission of the materials as thin films is dominated by local effects in the packing of the materials that are unique for each case as the structures are distinct from one another. Charge mobility (as calculated from the crystal structures) is not favoured because of twisted conformations and large displacement, but the sometimes high emission and large Stokes shift could make the materials interesting for other purposes, such as light emitters.