A 2D Covalent Organic Framework with 4.7-nm Pores and Insight into Its Interlayer Stacking

Abstract

Two-dimensional layered covalent organic frameworks (2D COFs) organize π-electron systems into ordered structures ideal for exciton and charge transport and exhibit permanent porosity available for subsequent functionalization. A 2D COF with the largest pores reported to date was synthesized by condensing 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) and 4,4'-diphenylbutadiynebis(boronic acid) (DPB). The COF was prepared as both a high surface area microcrystalline powder as well as a vertically oriented thin film on a transparent single-layer graphene/fused silica substrate. Complementary molecular dynamics and density functional theory calculations provide insight into the interlayer spacing of the COF and suggest that adjacent layers are horizontally offset by 1.7-1.8 Å, in contrast to the eclipsed AA stacking typically proposed for these materials.

Self-templated chemically stable hollow spherical covalent organic framework

“…It is noteworthy that the application of COFs is still mostly limited to the storage of gas molecules, since most of the COFs synthesized are microporous in nature and their pores are not sizable enough to hold larger guests, such as enzymes [38][39][40] . While examples of mesoporous boronic acid-based COFs have been reported in the literature 41,42 their chemical instability prevents the usage of these materials for the storage of drugs and enzymes 43,44 . Since the COF-DhaTab is chemically stable and mesoporous (3.7 nm), we can study the adsorption and storage of the enzyme trypsin into the COF pores.…”

Internal Functionalization of Three‐Dimensional Covalent Organic Frameworks

“…[2,3] The nearly eclipsed structures [4,5] of most 2D COFs give rise to high intrinsic charge mobilities [6] and their recent synthesis as oriented thin films [7] portends their use in optoelectronic and energy-storage devices. In contrast, few 3D COFs have been crystallized, and despite exhibiting exceptionally high surface areas (> 4000 m 2 g À1 ) and record low densities (0.17 g cm À3 ), these networks have no well-developed applications.…”

Synthetische kovalente und nichtkovalente zweidimensionale Materialien

“…[65] Die gleiche Arbeitsgruppe synthetisierte ein 2D-COF durch Kondensation von 2,3,6,7,10,11-Hexahydroxytriphenylen und 4,4'-Diphenylbutadiinbis(boronsäure) auf von transparentem Quarzglas getragenem SLG mit einer Porengrçße von 4.7 nm, der grçßten, die bisher für ein 2D-COF-System beschrieben wurde (Abbildung 2d). [66] Diese Porengrçße grenzt bereits an den mesoporçsen Bereich, in dem die Verwendung von 2D-Materialien als Wirte für polymere und anorganische Gastmoleküle mçglich ist. Mit Moleküldynamik-und Dichtefunktionaltheorie(DFT)-Rechnungen wurde gezeigt, dass benachbarte 2D-Schichten anders als andere,ä hnliche Materialien nicht vollständig aufeinander liegen, sondern lateral um 1.7-1.8 v ersetzt sind.…”