Anhydrous proton-conductive materials have attracted great attention in recent years. Doping imidazole as a proton carrier in porous materials, especially pure organic crystalline covalent organic frameworks (COFs), is a promising solution. However, the influence of the hydrogen donor ability of imine functional groups in COFs on the proton conduction has largely been unexplored. Herein, a series of iso-reticular thiophene-based COFs has been synthesized with a similar pore structure and surface area. Different amounts of imidazole were infiltrated to the COFs by vapor diffusion in a highly controlled manner. The introduction of thiophene rings increases the hydrogen bonding donation ability of the imine linker, which resulted in an enhanced proton conductivity of the imidazole-doped COFs by one order of magnitude. The formation of hydrogen bonding between the imine group and imidazole was demonstrated by Fourier transform infrared spectroscopy and density functional theory calculations.

The metalloid-centered covalent organic framework has attracted great interestf rom both its structure and application.H eavier elements have seldomly been incorporated in the covalent organic frameworks, even if they exhibit special structural features and properties. Herein, we reportedt he first crystalline germanate covalent organic framework with hexacoordinated germanate linked by an anthracene linker.T he existence of counterion lithium ions in the framework provides ah igh CO 2 uptake of 88.5 cm 3 g À1 at 273 Kand ahighCO 2 /N 2 selectivity of 101. As ignificantly improved lithium ion conductivity of 0.25 mS cm À1 at room temperature was observed due to the soft germanium center.Covalento rganic frameworks (COFs) are highly crystalline porouso rganic materials linked by strong covalentb onds with designable features,w hich resulted in at unable topology and pore structure. During the last decade, COFs have witnessed a rapid development and found wide applications in gas adsorption and separation, catalysis, optoelectronics, chemical sensing, energy storage, etc. [1] Recently,aseries of ionic covalent organic frameworks has been constructed witha nionic or cationic structural motifs, which has attracted huge attention due to their potential applicationsi ng as adsorption,d ye adsorption, metal-ion adsorption,a ntimicrobial, catalysis and more importantly solid-state ion conduction. [2] The availability of anionic COFs is limited, most of them are connected by tetrahedral boron or hexahedral silicon. [2g,h,m] The elements over the third row have al arger atom radius andm ultiple valence and are ideal candidates for the ionic center. However,h eavier ele-ments have seldomly been incorporated in the covalentorganic frameworks, even if they exhibit special structural features and properties. [3] Porous crystalline germanate inorganic frameworks consisting of only GeÀOc lusters have been synthesized in the late 90s and attracted great interest since then. [4] Germanate inorganic frameworks exhibit ar ich structurald iversity due to the combination of av arious number of GeO 4 tetrahedron,G eO 5 trigonal bipyramids,a nd aG eO 6 octahedron.T he design and functionalization of at argeted germanate inorganic framework are extremely difficult partly due to the uncertain combination of germanate clusters. The isolation of single germanate node would facilitate the design and control synthesis of germanate frameworks. However,t he incorporation of ag ermanate cluster in the porous organicf ramework is largely unexplored.Herein, we report the first crystalline germanate covalent organic framework (Ge-COF-1) by the combination of ah ex-coordinated germanate center with at etrahydroxylated anthracene in high yield. The resulting germanate covalent organic framework exhibits ah ighC O 2 uptake and selectivity over N 2 ,a nd a high Li ion conductivity in its pristine state as well as doped state among other anionic covalentorganic frameworks.Ge-COF-1 was synthesized by am icrowave heatingo fg ermaniumd ioxide and 9,1...

Anionic covalent organic framework is an emerging class of functional materials in which included ionic species of the opposite charges play an important role in the ion conduction and selective gas adsorption. Herein, we reported a facile method to construct a series of germanate-based anionic COFs (Ge-COFs) by reticulating dianionic hexa-coordinated GeO6 nodes with anthracene building blocks adopting a hcb topology in an extended 2D framework. A systematic change of pore properties in Ge-COFs was observed through the incorporation of three different alkali metal cations: Li+, Na+, and K+. The intrinsically negatively charged backbone provides a host matrix with a homogeneous distribution of counter cations and poses variable and exciting features for gas adsorption and ionic conduction. Among the series, K+-based Ge-COF-K with a surface area of 1252 m2/g and pore volume of 0.84 cm3/g shows a maximum CO2 uptake of 126 cm3/g (247.4 mg/g) at 273 K and 1 bar, an IAST selectivity of 140 over N2. Ge-COF-K also exhibits a high SO2 kinetic breakthrough capacity of 154 mg/g at low ppm of SO2 concentration under ambient conditions among recently reported porous materials. Moreover, reasonably high lithium, sodium, and potassium ionic conductivities were observed with the values of 1.2 × 10–4, 3.4 × 10–5, and 2.2 × 10–5 S/cm for propylene carbonate infiltrated Ge-COF-Li, Ge-COF-Na, and Ge-COF-K at 100 °C, respectively.

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A 3D thiophene based POF was post-oxidized by m-CPBA in a controllable manner with a less effected pore width. The introduction of sulfone groups promotes the adsorption of ammonia and enhances the proton conductivity of doped POFs.