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oe1(光电查) - 科学论文

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?? 中文（中国） ▾

  • A comprehensive photophysical and NMR investigation on the interaction of a 4-methylumbelliferone derivative and cucurbit[7]uril

    摘要： The host-guest interaction of a 7-hydroxycoumarin (3-[2-(diethylamino)ethyl]-7-hydroxy-4-methylcoumarin, 3ED4MU) with cucurbit[7]uril, CB7, was investigated in aqueous solution. From the steady-state fluorescence Job plot and 1H NMR spectroscopy the formation of a 1:1 inclusion complex, with a binding constant of 1.75×105 M?1 was obtained. Time-resolved fluorescence data in water, DMSO and dioxane for 3ED4MU and for umbelliferone (UM, here taken has the model compound) show that the decays are double or triple-exponentials mirroring the presence of excited neutral (N*), anionic (A*), tautomeric (T*) and zwiterionic (T*’) species (the latter only present in 3ED4MU). In the time-resolved experiments, the interaction of 3ED4MU with CB7 is mirrored by an increase of the pre-exponential factor associated to the zwiterionic species (thus giving support for the stabilization of this species when interacting with CB7) and a dramatic change in the pKa* value (from ~ 0.5 to ~8), associated to a displacement of the water environment probed by 3ED4MU.

    关键词： Time-resolved fluorescence,Host-guest chemistry.,Binding constant,Fluorescence,Hydroxycoumarins,Cucurbit[7]uril

    更新于2025-09-23 15:23:52

  • Nanometer control in plasmonic systems through discrete layer-by-layer macrocyclea??cation deposition

    摘要： In this work, we demonstrate that coordination interactions between Fe3+ and cucurbit[7]uril (CB[7]) can be utilised to build up defined nanoscale spacing layers in metallic nanosystems. We begin by characterising the layer-by-layer deposition of CB[7] and FeCl3?6H2O coordination layers through the use of a Quartz-Crystal Microbalance (QCM) and contact angle measurements. We then apply this layered structure to accurately control the spacing, and thus optical properties, of gold nanoparticles in a Nanoparticle-on-Mirror (NPoM) structure, which is demonstrated via normalising plasmon resonance spectroscopy.

    关键词： nanoscale,Fe3+,plasmonic,coordination,cucurbit[7]uril

    更新于2025-09-23 15:21:01