Host-guest interactions: a fluorescence investigation of the solubilization of diphenylpolyene solute molecules in lipid bilayers

Effect of Sonication on the Thermotropic Behavior of DODAB Vesicles Studied by Fluorescence Probe Solubilization

“…Similar result was also reported by Allen et al for 4B4A and 4H4A solubilized in phospholipid liposomes [20] and in mixtures of cationic lipids with co-surfactants [23,24]. It was also observed that an increase in the separation length between the phenyl groups of t-Dpo reduces the probe ability to be aligned with the hydrocarbon chains, thus explaining the different accommodation of these probes in the bilayer giving different fluorescence signals [20]. Deviation in the U f curves may be related not only to the probe chemical structure but also to the vesicle size, lipid packing and the vesicle architecture as a result of sonication.…”

“…Fluorescence spectroscopy is useful for investigating microenvironments in vesicle bilayers whose local viscosity and polarity influence the fluorescence response of solubilized probes [14,[19][20][21]. Fluorescence spectra of the probes give information about the bilayer organization and state of the lipid chains [19].…”

“…Fluorescence spectra of the probes give information about the bilayer organization and state of the lipid chains [19]. In the particular case of the trans-diphenylpolyene (t-Dpo) derivatives the excited fluorophores solubilized in the bilayer are isomerized and the competition between the fluorescence and the fluorophore photoisomerization results in a decrease in the total fluorescence intensity [14,20]. Above T m , in the liquidcrystalline state, the higher mobility of the probes favors photoisomerization yielding a decrease in the total fluorescence intensity (I f ), quantum yield (U f ) and anisotropy (\r[), that can be monitored as a function of temperature to obtain the vesicle T m .…”

Reversible Switching of a Micelle‐to‐Vesicle Transition by Compressed CO2

“…[44] The rigidity of the microenvironment can impact on the observed fluorescence quantum yields by restricting certain vibrational modes within the excited-state fluorophore, which may lead to the ground state through nonradiative decay processes. [45] A typical curve of the fluorescence quantum yield F f of trans,trans-1,4-diphenyl-1,3-butadiene (DPB) in DTAB/SDS solution at different pressures of CO 2 determined herein is shown in Figure 8. Similarly, the quantum yield increased slowly with pressure below approximately 2.40 MP, and increased quickly when the pressure was further increased because of rupture of the micelles and formation of vesicle membranes.…”

Substituent Effects on Crosslike Packing of 2′,7′‐Diaryl‐ spiro(cyclopropane‐1,9′‐fluorene) Derivatives: Synthesis and Crystallographic, Optical, and Thermal Properties

“…Fourth, comparing compounds 5 and 9, the replacement of the phenylene group by the thiophene group should destabilize the highest occupied molecular orbital (HOMO) and stabilize the lowest unoccupied molecular orbital (LUMO) of 9 and result in further decrease of the [a] The excitation wavelengths used were their related maximum absorption wavelength. [b] The photoluminescence quantum yields (UPL) of these compounds (1)(2)(3)(4)(5) in cyclohexane were determined using a solution of trans,trans-1,4-diphenylbuta-1,3-diene as the standard (UPL= 0.44 in cyclohexane) [20].…”