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Conjugated organic frameworks are an interesting class of functional porous organic materials having a π-conjugated backbone with permanent porosity. These materials are potential candidates for optoelectronic applications. Although there are several reports on the structure–property relationship between π-conjugated building blocks and optoelectronic performance, the influence of the linker position is hitherto unknown. We report two novel imine-linked 2D π-conjugated polymers which are positional isomers of each other consisting of pyrene and anthracene units. The polymers exhibited similar optical and electronic properties under ambient conditions. Upon I2 doping, one of the isomers exhibited high radical density and enhanced conductivity due to energetically favoured chemical oxidation. The linker position dramatically affects the optoelectronic performance of these polymers even though they have the same π-conjugated backbone.

We describe the preparation of the crystalline and glassy state of a coordination polymer displaying proton conduction and guest-accessible porosity. EXAFS and solid-state NMR analyses indicated that pyrophosphate and phosphate ions are the main proton transporters in the glass and that homogeneously distributed 5-chloro-1H-benzimidazole in the glass provides the porosity.

Polyoxometalate based solids are promising candidates of proton-conducting solid electrolytes. In this work, a Preyssler-type polyoxometalate is crystallized with potassium ions and poly(allylamine), which is also a good proton conductor, from aqueous solutions. Here we show that the hygroscopicity induced low durability of polyoxometalate and poly(allylamine) can be circumvented by the electrostatic interaction between the polyoxometalate and protonated amine moieties in the solid state. Crystalline compounds are synthesized with poly(allylamine) of different average molecular weights, and all compounds achieve proton conductivities of 10−2 S cm−1 under mild-humidity and low-temperature conditions. Spectroscopic studies reveal that the side-chain mobility of poly(allylamine) and hydrogen-bonding network rearrangement contribute to the proton conduction of compounds with poly(allylamine) of low and high average molecular weights, respectively. While numbers of proton-conducting amorphous polyoxometalate-polymer composites are reported previously, these results show both structure-property relationship and high functionality in crystalline composites. Polyoxometalate based solids are promising candidates for proton-conducting electrolytes but their low durability and low proton conductivities remains an on-going challenge. Here the authors describe the preparation of polyoxometalate-based solids with much improved stability and proton conductivities.

Polymerization of monosaccharide monomers usually suffers from the production of polysaccharides with ill-defined structures because of the uncontrolled random reactions among many reactive hydroxyl groups on saccharide monomers. In particular, rational synthesis of polysaccharides with porosity approximating molecular dimensions is still in its infancy, despite their usefulness as drug carriers. Here, we disclose an efficient synthetic methodology for the preparation of polysaccharides with controllable mesoporosity in the structure, utilizing [Cu3(benzene-1,3,5-tricarboxylate)]n (HKUST-1; 1) as templates. Cationic ring-opening polymerization of 1,6-anhydro glucose was performed in nanochannels of 1, followed by removal of the host frameworks, giving polysaccharide particles as replicas of the original molds. Nitrogen adsorption measurement revealed that the obtained polysaccharide particles contained high mesoporosity in the structure, which could be controlled systematically depending on the polymeriza...

The mechanical strength of metal-organic frameworks (MOFs) is highly relevant for their practical applications. In this research, we show that encapsulation of polymer chains into MOF nanochannels can effectively restrain the breakage of coordination bonding in MOFs and inhibit the amorphization under high physical pressure. The hardness of single MOF crystals was greatly improved, which depended on the direction of the inserted polymers, as revealed by nanoindentation analysis. Insertion of polymer chains did not influence the crystal structure of MOFs, which indicates that this approach should be highly promising for improving the mechanical properties of MOFs.

We demonstrate a feasible method for the preparation of polyglucose (PGlc) with controlled structures, where the polymerization of glucose monomers was performed using one-dimensional nanochannels of [La(1,3,5-benzenetrisbenzoate)(H2O)]n (1). Cationic ring-opening polymerization of 1,6-anhydro-β-D-glucose (levoglucosan) using 1 gave a quasi-linear PGlc, which contrasts highly with the results obtained from conventional polymerizations in bulk and solution. The regulated structure of PGlc prepared using the PCP led to a remarkable improvement in the processability and thermal stability of PGlc, which is useful in applications as a bioplastic.

Thermal ring-opening polymerization of the unsymmetrically substituted [1]ferrocenophane was performed in one-dimensional nanochannels of porous coordination polymers (PCPs). In contrast to conventional thermal polymerization in bulk, formation of cyclic polymer was inhibited in the channels. In addition, the tacticity of the resulting polymer was dependent on the pore size of PCPs.