Host-Guest Complexation Studied by Fluorescence Correlation Spectroscopy: Adamantane–Cyclodextrin Inclusion
نویسندگان
چکیده
The host-guest complexation between an Alexa 488 labelled adamantane derivative and beta-cyclodextrin is studied by Fluorescence Correlation Spectroscopy (FCS). A 1:1 complex stoichiometry and a high association equilibrium constant of K = 5.2 x 10(4) M(-1) are obtained in aqueous solution at 25 degrees C and pH = 6. The necessary experimental conditions are discussed. FCS proves to be an excellent method for the determination of stoichiometry and association equilibrium constant of this type of complexes, where both host and guest are nonfluorescent and which are therefore not easily amenable to standard fluorescence spectroscopic methods.
منابع مشابه
Surface modification of polymeric vesicles via host-guest inclusion complexation.
We have prepared a novel kind of building block (CD-PI-CD) of polyether imide (PI) with beta-cyclodextrin (beta-CD) at the both ends that self-assembles into vesicles in water. The vesicles are "reactive" in supramolecular chemistry because the host groups of beta-CD equally distribute on the inside and outside surfaces of the vesicles. Isothermal titration calorimetry (ITC) and static light sc...
متن کاملPositive variation of the MRI signal via intramolecular inclusion complexation of a C-2 functionalized β-cyclodextrin.
The synthesis of a new contrast agent based on a β-cyclodextrin scaffold and bearing a flexible lipophilic spacer arm on its secondary face is reported. Intermolecular host-guest inclusion complexes were known to undergo an enhancement of the contrast imaging. We extend this concept to intramolecular complexation. Inter- and intramolecular interactions are compared by NMR spectroscopy, circular...
متن کاملSuperstructures of fluorescent cyclodextrin via click-reaction
Mono-(6-azido-6-deoxy)-β-cyclodextrin (CD) was covalently attached to an alkyne-modified 5-methyl-2-(pyridin-2-yl)thiazol-4-ol yielding a fluorophore containing CD in a click-type reaction. Intermolecular complexes were formed by poly(host-guest)-interactions. The supramolecular structures were characterized by (1)H NMR-ROESY spectroscopy, dynamic light scattering, UV-vis spectroscopy, fluoresc...
متن کاملFluorescence quenching in β-cyclodextrin vesicles: membrane confinement and host-guest interactions.
Fluorescent β-cyclodextrin vesicles (β-CDV) that display host cavities available for host-guest interactions at the vesicle surface were prepared by incorporation of the hydrophobic spirobifluorene-based dye 1 into the membrane of unilamellar vesicles. Fluorescence quenching of dye 1 was observed in the presence of different quenchers. Methyl viologen 2 does not quench dye 1 because it does not...
متن کاملBinding behavior of aliphatic oligopeptides by bridged and metallobridged bis(beta-cyclodextrin)s bearing an oxamido bis(2-benzoic) carboxyl linker.
beta-Cyclodextrin dimers bearing an oxamido bis(2-benzoic) carboxyl linker (1) or its metal complexes (2 and 3) were newly synthesized, and their inclusion complexation behavior with a series of representative aliphatic oligopeptides, i.e., Leu-Gly, Gly-Leu, Gly-Pro, Glu-Glu, Gly-Gly, Gly-Gly-Gly, and Glu(Cys-Gly), was elucidated by means of UV/vis, circular dichroism, fluorescence, and 2D NMR ...
متن کامل