Journal ArticleDOI
Tautomerization of lumichrome promoted by supramolecular complex formation with cucurbit[7]uril
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TLDR
In this paper, cucurbit[7]uril was added to an aqueous solution of lumichrome and the formation of a new red-shifted band in both the absorption and fluorescence spectra indicating that binding to this rigid macrocyclic host facilitated the partial transformation into isoalloxazine-type structure.Abstract:
Addition of cucurbit[7]uril to an aqueous solution of lumichrome led to the formation of a new red-shifted band in both the absorption and fluorescence spectra indicating that binding to this rigid macrocyclic host facilitated the partial transformation into isoalloxazine-type structure. Global analysis of the results of spectrophotometric and spectrofluorometric titrations provided log K = 3.92 ± 0.06 for the logarithm of the equilibrium constant of 1:1 association. The dual fluorescence of the complex was quenched by protons in a diffusion-controlled process. Cucurbit[7]uril was found to exert negligible effect on the deprotonation of lumichrome in basic solution.read more
Citations
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Fluorescent dyes and their supramolecular host/guest complexes with macrocycles in aqueous solution.
TL;DR: Fluorescent Dyes and Their Supramolecular Host/Guest Complexes with Macrocycles in Aqueous Solution and how these complexes interact with each other and with solvent-free substrates is studied.
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Cucurbituril chemistry: a tale of supramolecular success
TL;DR: Cucurbit[n]urils have become key units in various self-organizing and stimulus-controlled assemblies, as well as in advanced materials and drug carriers.
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Applicable Properties of Cucurbiturils
TL;DR: In this paper, the authors highlight three significant fields of applications for cucurbiturils (CBs) and highlight the potential use of CBs for the assembly of mechanical devices and molecular motors.
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Photochromism in Cucurbit[8]uril Cavity: Inhibition of Hydrolysis and Modification of the Rate of Merocyanine–Spiropyran Transformations
Zsombor Miskolczy,László Biczók +1 more
TL;DR: The effect of CB8 on the reaction kinetics strongly altered with pH and the transition from the spiropyran form to trans-MC in a thermal reaction had 33 kJ mol(-1) lower activation energy and more than 5 orders of magnitude smaller Arrhenius pre-exponential factor in CB8 than in water.
Journal ArticleDOI
Determination of ranitidine, nizatidine, and cimetidine by a sensitive fluorescent probe
TL;DR: A validated, simple, and sensitive fluorescence quenching method for the determination of ranitidine, nizatidine, and cimetidine in tablets and biological fluids is presented and is the first single fluorescence method reported for the analysis of all three H(2) antagonists.
References
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Journal ArticleDOI
The cucurbit[n]uril family
TL;DR: In 1981, the macrocyclic methylene-bridged glycoluril hexamer (CB[6]) was dubbed "cucurbituril" by Mock and co-workers because of its resemblance to the most prominent member of the cucurbitaceae family of plants--the pumpkin.
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Excited-state proton transfer: from constrained systems to "super" photoacids to superfast proton transfer.
TL;DR: This work has used knowledge of the electronic structure of excited states of acids to design molecules that exhibit enhanced excited-state acidity and are the strongest reversible photoacids known.
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Complexation of ferrocene derivatives by the cucurbit[7]uril host: A comparative study of the cucurbituril and cyclodextrin host families
Woo Sung Jeon,Kwangyul Moon,Sanghyun Park,Hyungpil Chun,Young Ho Ko,Jin Yong Lee,Eunsung Lee,Shashadhar Samal,Narayanan Selvapalam,Mikhail V. Rekharsky,Vladimir Sindelar,David Sobransingh,Yoshihisa Inoue,Angel E. Kaifer,Kimoon Kim +14 more
TL;DR: The data suggest that cucurbiturils may form very stable complexes, however, the host-guest interactions are very sensitive to some structural features, such as a negatively charged carboxylate group attached to the ferrocene residue, which may completely disrupt the stability of the complexes.
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Host-guest complexation of neutral red with macrocyclic host molecules: contrasting pK(a) shifts and binding affinities for cucurbit[7]uril and beta-cyclodextrin.
TL;DR: The photophysical properties of both NR and NRH+ forms showed significant changes in the presence of CB7, suggesting an entropic driving force for complexation related to desolvation of the cation and the removal of high-energy water molecules from the CB7 cavity.
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Cucurbituril Encapsulation of Fluorescent Dyes
Apurba L. Koner,Werner M. Nau +1 more
TL;DR: The potential of cucurbiturils, water-soluble macrocyclic host molecules composed of glycoluril units, for tuning the properties of fluorescent dyes and advancing new applications is illustrated and original experimental results for the effect of CB7 on the fluorescence properties of three dyes are presented.