A study of the inclusion complexes of β-cyclodextrin with three electronic states of 4-(N,N-dimethylamino)benzonitrile

Baraka, Mohamed El; García, Rosario Merino; Quiñones, Edwin

doi:10.1016/1010-6030(93)03765-9

Cited by 20 publications

(11 citation statements)

References 18 publications

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“…Even though chemical recognition features are not usually involved, we use this opportunity to give a snapshot of the field since it represents the fluorescent signaling of a chemically crucial parameter. Compound 79 in aqueous β-cyclodextrin solution displays a temperature-invariant TICT emission, whereas the fluorescence from the ICT-type delocalized ICT state decreases significantly at higher temperatures …”

Section: Twisted Internal Charge Transfer (Tict) Excited Statesmentioning

confidence: 99%

“…So its fluorescence is opposite in direction and smaller in magnitude upon addition of 1-pentanol as a guest. These experiments were guided by data gathered from intermolecular interactions between cyclodextrins and TICT fluorophores. − Newer data are also available . The 5-(dimethylamino)naphthalene-1-sulfonamide fluorophore also makes an appearance in another version of 99 .…”

Section: Twisted Internal Charge Transfer (Tict) Excited Statesmentioning

confidence: 99%

“…Compound 79 in aqueous β-cyclodextrin solution displays a temperature-invariant TICT emission, whereas the fluores- cence from the ICT-type delocalized ICT state decreases significantly at higher temperatures. 353 Although the system is complicated by the different locations available to 79 in each of its electronic states, it permits ratioing of two emissions to give self-calibrated sensing. TICT state involvement is also suspected to control the thermal fluorescent response of 88 and 89 embedded within membranes of live cells.…”

Section: Twisted Internal Charge Transfer (Tict) Excited Statesmentioning

confidence: 99%

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Signaling Recognition Events with Fluorescent Sensors and Switches

et al. 1997

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Section: Twisted Internal Charge Transfer (Tict) Excited Statesmentioning

confidence: 99%

Section: Twisted Internal Charge Transfer (Tict) Excited Statesmentioning

confidence: 99%

Section: Twisted Internal Charge Transfer (Tict) Excited Statesmentioning

confidence: 99%

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Signaling Recognition Events with Fluorescent Sensors and Switches

et al. 1997

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“…Monitoring changes in absorbance at 280 nm we calculated the binding constant of gadolinium to apo azurin, Gd(III) 1 apo azurin ¼ Gd-azurin. A plot of log{(A ÿ A o )/(A Gd ÿ A)} against log[Gd 31 ], gives a straight line that corresponds to log K eq (El Baraka et al, 1994). The equilibrium constant was estimated to be K eq ¼ 3.31 3 10 3 M ÿ1 , which in turn allowed us to estimate DG 0 % ÿ20 kJ/mol, indicating that the metal gives stability to the structure.…”

Section: Properties Of Gadolinium-azurinmentioning

confidence: 99%

Conformational Changes in Azurin from Pseudomona aeruginosa Induced through Chemical and Physical Protocols

Fuentes

Oyola

Fernández

et al. 2004

Biophysical Journal

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Azurin from Pseudomona aeruginosa is a small copper protein with a single tryptophan (Trp) buried in the structure. The Gibbs free energies associated with the folding of holo azurin, calculated monitoring Trp fluorescence and changes in absorbance on the ligand-to-metal band, are different because these techniques probe their local environments, thereby being able to probe different conformational changes. The presence of an intermediate state was observed during the chemical denaturation of the protein. Upon denaturation, a 30-fold increase is observed in the magnitude of the quenching constant of the tryptophan fluorescence by acrylamide, because this residue becomes more accessible to the quencher. Entrapping the protein in sol-gel materials lowers its stability possibly because the solvation properties of the macromolecule are changed. The thermal denaturation of azurin immobilized in a sol-gel monolith is irreversible, which tends to rule out an aggregation mechanism to account for the irreversibility of the denaturation of the protein free in solution. Unlike the Cu(II) ion, the Gd(III) ion accommodates in site B of azurin with high affinity and the folding free energy of Gd-azurin is larger than that of apo azurin.

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“…Fluorimetric titrations enabled the determination of stability constants for LiL2 + (Figure 3) and KL2 + complexes ( Figure S12 stability constant determined by UV and fluorescence spectroscopies are considerably different (Table 2). This inconsistency could be caused by photochemical effects, [68][69][70] i.e. the equilibrium constant determined by emission spectroscopy could correspond to the reaction involving reactants and products in their excited states, or could be a function of both, excited-and ground-state reactions.…”

Section: Solvent: Acetonitrile/dichloromethane (L2)mentioning

confidence: 99%

Synthesis of Fluorescent Diphenylantracene-Based Calix[4]arene Derivatives and their Complexation with Alkali Metal Cations

et al. 2017

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Two novel fluorescent calix [4]arenes comprising diphenylanthracene moiety at the lower rim were synthetized and their complexation with alkali metal cations in acetonitrile/dichloromethane and methanol/dichloromethane mixtures (φ = 0.5) was studied experimentally and by classical molecular dynamics and quantum chemical calculations. The monosubstituted calixarene derivative (L1) proved to be a poor cation receptor, whereas the ester-based macrocycle (L2) exhibited rather high affinity towards lithium, sodium and potassium cations, particularly in MeCN/CH2Cl2. All complexation reactions were enthalpically controlled, whereby the overall stability was the largest in the case of sodium complex. The computational investigations provided an additional insight into the complexation properties and structures of complex species. The molecular dynamics simulations indicated the occurrence of inclusion of solvent molecules in the calixarene hydrophobic cavity of the free and complexed ligand, which was found to significantly affect the complexation equilibria.

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A study of the inclusion complexes of β-cyclodextrin with three electronic states of 4-(N,N-dimethylamino)benzonitrile

Cited by 20 publications

References 18 publications

Signaling Recognition Events with Fluorescent Sensors and Switches

Signaling Recognition Events with Fluorescent Sensors and Switches

Conformational Changes in Azurin from Pseudomona aeruginosa Induced through Chemical and Physical Protocols

Synthesis of Fluorescent Diphenylantracene-Based Calix[4]arene Derivatives and their Complexation with Alkali Metal Cations

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