Free-Standing Monolayer Two-Dimensional Supramolecular Organic Framework with Good Internal Order

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• 作者：Martin Pfeffermann ; Renhao Dong ; Robert Graf ; Wojciech Zajaczkowski ; Tatiana Gorelik ; Wojciech Pisula ; Akimitsu Narita ; Klaus M眉llen ; Xinliang Feng
• 刊名：Journal of the American Chemical Society
• 出版年：2015
• 出版时间：November 18, 2015
• 年：2015
• 卷：137
• 期：45
• 页码：14525-14532
• 全文大小：526K
• ISSN：1520-5126

文摘

Utilizing dynamic self-assembly and self-sorting to obtain large-area, molecularly precise monolayered structures represents a promising approach toward two-dimensional supramolecular organic frameworks (2D SOF) or 2D supramolecular polymers. So far, related approaches suffer from small domain sizes, fragility and weak long-range internal order. Here we report on the self-assembly of a host鈥揼uest enhanced donor鈥揳cceptor interaction, consisting of a tris(methoxynaphthyl)-substituted truxene spacer, and a naphthalene diimide substituted with N-methyl viologenyl moieties as donor and acceptor monomers, respectively, in combination with cucurbit[8]uril as host monomer toward monolayers of an unprecedented 2D SOF. Featuring orthogonal solubility, the participating molecules self-assemble at a liquid鈥搇iquid interface, yielding exceptionally large-area, insoluble films, which were analyzed by transmission electron microscopy, atomic force microscopy and optical microscopy to be monolayers with a thickness of 1.8 nm, homogeneously covering areas up to 0.25 cm², and featuring the ability to be free-standing over holes of 10 渭m². Characterization with ultraviolet鈥搗isible absorption spectroscopy, solid-state nuclear magnetic resonance spectroscopy, infrared spectroscopy, and grazing incidence wide-angle X-ray scattering allowed for confirmation of a successful complexation of all three monomers toward an internal long-range order and gave indications to an expected hexagonal superstructure. Our results extend the existing variety of two-dimensional soft nanomaterials by a versatile supramolecular approach, whereas the possibility of varying the functional monomers is supposed to open adaptability to different applications like membranes, sensors, molecular sieves, and optoelectronics.