Approaching two-dimensional copolymers: photoirradiation of anthracene- and diaza-anthracene-bearing monomers in Langmuir monolayers.
Approaching two-dimensional copolymers: photoirradiation of anthracene- and diaza-anthracene-bearing monomers in Langmuir monolayers.
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DOI：
10.1002/marc.201400569
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发表时间：
2015
影响因子：
4.6
通讯作者：
Payam Payamyar;M. Servalli;Tim Hungerland;Andri Schütz;Zhikun Zheng;A. Borgschulte;A. Dieter Schlüter
中科院分区：
文献类型：
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作者：
Payam Payamyar;M. Servalli;Tim Hungerland;Andri Schütz;Zhikun Zheng;A. Borgschulte;A. Dieter Schlüter
通过使用结构相似的两亲性单体，研究表明，在空气/水界面上不同数量的两亲性单体的压缩单层可以通过光照射转化为相应的共价连接的单层片。由于其中一个单体携带三个蒽单元，另一个携带三个1,8-二氮杂蒽单元，因此生长反应被认为是通过光化学方法在这些共面排列的单元对之间实现[4+4]环加成，以提供相应的共价二聚体。虽然这两种同型二聚体的证据都很充分，但需要在模型反应的帮助下确定异型二聚体的存在，以支持这项工作的概念方面，即二维共聚。薄片共聚物具有很强的鲁棒性，它们可以跨越20 × 20 μm(2)大小的孔而不会在自身重量下破裂。x射线光电子能谱（XPS）研究表明，单体根据进料的不同被掺入到薄片共聚物中。这些结果确定了第一个共价层共聚物的存在，这被认为是迈向新型二维材料的一步。
By using structurally similar amphiphilic monomers, it is shown that compressed monolayers of varying amounts of such monomers at the air/water interface can be converted by photo-irradiation into the corresponding covalently connected monolayer sheets. Since one of the monomers carries three anthracene units and the other three 1,8-diaza-anthracene units, the growth reaction is proposed to take place through photochemically achieved [4+4]-cycloaddition between pairs of these units that are co-facially (face-to-face) arranged, to furnish the corresponding covalent dimers. While evidence for both homodimers is amply available, the existence of the heterodimer needs to be established with the help of a model reaction to support the conceptual aspect of this work, copolymerization in two dimensions. The sheet copolymers exhibit substantial robustness in that they can be spanned over 20 × 20 μm(2)-sized holes without rupturing under their own weight. X-ray photoelectron spectroscopy (XPS) studies reveal that the monomers are incorporated into the sheet copolymers according to feed. These results establish existence of the first covalent sheet copolymer, which is considered a step ahead towards novel 2D materials.