L-Tryptophan-modified beta-cyclodextrin (L-Trp-beta-CD) has been synthesized and its molecular recognition behavior investigated through fluorescence and circular dichroism spectrometry, as well as fluorescence lifetime measurement in the presence and absence of various alcohols as guest molecules. Employing the indolyl group as a spectral probe, spectrofluorometric and spectropolarimetric titrations have been performed in aqueous phosphate buffer solution at pH 7.20 to calculate the complex stability constants for 1:1 inclusion complexation of L-Trp-beta-CD with several series of alcohols at 25 degrees C. The results obtained indicate that L-Trp-beta-CD can recognize not only size/shape and hydrophobicity but also the enantiomeric and geometrical isomers of the guest alcohols, showing a 230-fold molecular selectivity (13.5 kJ mol(-)(1)) for 2-adamantanol over cyclopentanol among the cyclic alcohols examined. Moderate enantiomeric selectivities of 1.2 and 1.9 for (-)-isomers of borneol and menthol, respectively, and geometrical selectivity of 2.0 for geraniol over nerol have also been observed.

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A novel TPE-functionalized pillar[5]arene (TPEP5) was successfully synthesized, and the motion of the TPE motif was restricted via pillararene-based host–guest recognition-mediated cross-linking, resulting in the efficient “turn-on” of fluorescence emission based on the AIE mechanism.

A series of new conjugated polymers PTPExFy, which consist of tetraphenylethylene (TPE) units and fluorene (F) units, have been designed and synthesized by Suzuki cross‐coupling polymerization. The polymers PTPExFy exhibited aggregation‐induced emission enhancement and dual‐channel fluorescence response (DCFR) when they were aggregated in solution, and these properties are related with their TPE‐to‐F ratio in the polymer backbone. For PTPE and PTPE0.5F0.5, the fluorescence emission was enhanced by aggregation when water was added into their THF solutions. For the copolymers PTPE0.3F0.7, PTPE0.2F0.8, and PTPE0.1F0.9, the DCFRs were observed when they were aggregated by adding water into their solution, which can be attributed to the different responses of fluorene segments and TPE segments to aggregation. The fluorene segments have an aggregation‐caused quenching characteristic, whereas the TPE segments have an aggregation‐induced emission characteristic. According to the fluorescence lifetime and quantum yield data of the polymer solutions, we have discovered that the polymer's natural life time increases as its TPE content increases. In the solid film, PTPE0.3F0.7 and PTPE0.2F0.8 showed better quantum yield than other polymers, due to the combination of the excellent fluorescent property of the fluorene groups and the nonplanar conformation of the TPE groups. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

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Windowing problems limit the resolution of conventional time-frequency analysis using the Short Time Fourier Transform (STFT) and interfere with valid measurement of seismic attenuation. Wavelet transform time-frequency spectral analysis eliminates windowing and consequently has very high temporal resolution. Synthetic studies show that the technique can be used to generate useful spectral attributes. Case studies indicate that the method allows anomalies to be seen on spectrally decomposed sections that may not be apparent on a broad-band stack. Application to various gas reservoirs indicates that wavelet transform time-frequency analysis can potentially be used for direct hydrocarbon detection using seismic attenuation in thick reservoirs, tuning-related peak frequency anomalies in thin reservoirs and low frequency shadows associated with hydrocarbons.

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