Density functional theory (DFT) and first principles molecular dynamics (FPMD) studies of pyrophosphate cluster NaPO and triphosphate cluster NaPO absorbed and decomposed on an FeO(0001) surface have been conducted. Comparative analyses of the structure properties and adsorption processes during the simulation at elevated temperature have been carried out. The results depict the key interactions including the covalent P-O bonds, pure ionic Na-O or Fe-O interactions. The iron oxide surface plays an important role in the bridging bond decomposition scheme which can both promote and suppress phosphate depolymerization. It is found that the chain length of polyphosphates does not have considerable effects on the decomposition of phosphate clusters. This study provides detailed insights into the interaction of a phosphate cluster on an iron oxide surface at high temperature, and in particular the depolymerization/polymerization of an inorganic phosphate glass lubricant, which has an important behavior under hot metal forming conditions.

Organic electrochemical transistors (OECTs) for bioelectronic applications require the design of conjugated polymers that are stable in aqueous environments and afford high energy efficiency and good performance in OECTs. Polymers based on poly­(ethylenedioxythiophene) (PEDOT) are promising in this area due to their low oxidation potential and reversible redox, but they often require cross-linking to prevent dissolution and yield OECTs operating in the less efficient depletion mode. In this work, a new conjugated polymer PEDOT-Phos is presented, which combines a conjugated poly­(ethylenedioxythiophene) (PEDOT) backbone with alkyl-protected phosphonate groups. PEDOT-Phos exhibits a low oxidation onset potential (−0.157 V vs Ag/AgCl) and its nanoporous morphology affords it a high volumetric capacitance (282 ± 62 F cm–3). Without any cross-linking, additives, or post-treatment, PEDOT-Phos can be used in aqueous OECTs with efficient accumulation mode operation, long-term stability when immersed in aqueous media, low threshold voltages (−0.161 ± 0.005 V), good transconductances (9.3 ± 1.8 mS), and ON/OFF current ratios (618 ± 54) comparable to other PEDOT-based materials in OECTs. These results highlight the great promise of PEDOT-Phos as a stand-alone channel material for energy-efficient, bioelectronic devices.

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The incorporation of a hexadecyl group on imidazolium, pyridinium, and pyrrolidinium scaffolds produces low-molecular-weight ionic organogelators that can gel several types of ionic liquids, deep eutectic solvents (DESs), and several molecular organic solvents. Minimum gelator concentrations fall in the 0.9–15.0% (w/v) range, with the lower end of the gelator concentrations observed in the gelation of DESs. On the basis of polarized optical microscopy, differential scanning calorimetry, and X-ray data, crystallization of these salts appear to produce high-surface-area crystals, which generate sufficiently stable three-dimensional networks that are capable of trapping the solvent molecules. Importantly, the nature of the fluid component of the gel appears to have a profound effect on the morphology of the crystallized organogelators. On the other hand, the organogelators appeared to modulate phase transitions of the liquids.

In situ ligand formation plays a unique role in the synthesis of metal− organic framework (MOF) materials. However, for a given metal−ligand system, in situ ligand formation can be limiting, especially for the synthesis of kinetically stable porous phases, because reaction conditions must be chosen to meet the requirements of both in situ ligand formation and MOF crystal growth. Such requirements may be mutually incompatible, because ligand formation involving the breaking of inert bonds may require conditions more harsh than those needed for the growth of porous materials. For homochiral MOFs, less harsh reaction conditions are also desirable because of the reduced risk for ligand racemization. In this study, we propose and demonstrate the concept that the use of presynthesized ligand (in place of in situformed ligand) to decouple the ligand synthesis reaction from MOF crystal growth allows access to more porous and kinetically stable phases that may not be possible through the in situ process. A homochiral Zn-D-camphorate-TPB system (TPB = 1,2,4,5-tetra(4-pyridyl)benzene) is chosen to illustrate this concept. A new homochiral MOF (CPM-322) has been synthesized that contains infinite homochiral sheets of zinc paddlewheel dimers and D-camphorate ligands. An exceptional feature is the novel X-pillaring mechanism, in distinct contrast with simple pillaring by rod-like ditopic ligands (here called the I-pillaring mechanism). The perfect geometry matching in both pillaring distances and angles between TPB X-pillars and wavy homochiral sheets allows the TPB ligand to act as X-shaped pillars that prop up homochiral layers with two pyridyl groups on each side, leading to a highly open and rigid three-dimensional homochiral porous framework.