ConclusionsWe have synthesized four isostructural porphyrinic MOFs and investigated their photoredox catalytic activities toward three representative organic transformations including aerobic hydroxylation of arylboronic acids, oxidative primary amine coupling, and the Mannich reaction.Compared to their molecular model compounds, porphyrinic MOF-based photocatalysts exhibit a considerably enhanced photostability and excellent recyclability. Most importantly, metalation with high-valent metal cations (In III and Sn IV ) significantly modifies the electronic structure of the porphyrin and provides a highly oxidizing photoexcited state that undergoes efficient reductive quenching processes to facilitate subsequent organic transformations. Porphyrin metalation indeed provides a convenient approach to fine-tune and optimize the photoredox catalytic activities of MOFs.
The spin state of [Fe(H2B(pz)2)2(bipy)] thin films is mediated by changes in the electric field at the interface of organic ferroelectric polyvinylidene fluoride with trifluoroethylene (PVDF-TrFE). Signatures of the molecular crossover transition are evident in changes in the unoccupied states and the related shift from diamagnetic to paramagnetic characteristics. This may point the way to the molecular magneto-electric effect on devices.
Biofuels are an important component of a sustainable fuel future. The implementation of such fuels into existing and new engine designs requires an understanding of their interactions with the engine’s components at temperature. The formation of soot deposits on hot metal components, when in contact with fuels at elevated temperatures, can reduce engine performance. We have devised a test rig to measure soot formation from individual biofuel components. Fuel can be sprayed onto metal surfaces up to 750 °C under a controlled atmosphere. Using this rig, we have studied the formation of carbon deposits on steel, nickel, and aluminum metals using the pure small molecule biofuels and fuel mixture simulants. The amount and chemical identity of the deposits formed were studied using Raman spectroscopy. Using this new method for soot quantification, we can more rapidly screen for low soot forming biofuels as promising biofuel candidates grow.
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