Switched "On" Transient Fluorescence Output from a Pulsed-Fuel Molecular Ratchet.

We report the synthesis and operation of a molecular energy ratchet that transports a crown ether from solution onto a thread, along the axle, over a fluorophore, and off the other end of the thread back into bulk solution, all in response to a single pulse of a chemical fuel (CClCOH). The fluorophore is a pyrene residue whose fluorescence is normally prevented by photoinduced electron transfer (PET) to a nearby -methyltriazolium group. However, crown ether binding to the -methyltriazolium site inhibits the PET, switching on pyrene fluorescence under UV irradiation.

Local Electronic Structure in γ-LiAlO Studied by Single-Crystal Al NMR and DFT Calculations.

From single-crystal Al NMR experiments, the full tensors for both the electrical field gradient (EFG) and the chemical shift (CS) for the aluminum atoms in γ-LiAlO have been determined. A simultaneous fit of the quadrupolar splittings observed for the four Al in the unit cell gave the EFG tensor in the crystal frame, from which a quadrupolar coupling constant of χ = C = 3.330 ± 0.