Complexing of .alpha.-cyclodextrin with sym-4,4'-disubstituted biphenyls

Connors, Kenneth A.; Paulson, Andrea; Toledo-Velasquez, David

doi:10.1021/jo00244a033

Cited by 61 publications

(54 citation statements)

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“…The first report on stability constants for G:CD formation was due to Sun et al [287] They studied the complexation between α-CD and bis(alkyl dimethylammonium)-2- 14,16 [289,290]. A structural analysis of the complex has been done by rotating frame nuclear…”

Section: CDmentioning

confidence: 99%

The formation of host–guest complexes between surfactants and cyclodextrins

Valente

Söderman

2014

Advances in Colloid and Interface Science

183

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Cyclodextrins are able to act as host molecules in supramolecular chemistry with applications ranging from pharmaceutics to detergency. Among guest molecules surfactants play an important role with both fundamental and practical applications. The formation of cyclodextrin/surfactant host-guest compounds leads to an increase in the critical micelle concentration and in the solubility of surfactants. The possibility of changing the balance between several intermolecular forces, and thus allowing the study of, e.g., dehydration and steric hindrance effects upon association, makes surfactants ideal guest molecules for fundamental studies. Therefore, these systems allow for obtaining a deep insight into the host-guest association mechanism. In this paper, we review the influence on the thermodynamic properties of CD-surfactant association by highlighting the effect of different surfactant architectures (single tail, double-tailed, gemini and bolaform), with special emphasis on cationic surfactants. This is complemented with an assessment of the most common analytical techniques used to follow the association process. The applied methods for computation of the association stoichiometry and stability constants are also reviewed and discussed; this is an important point since there are significant discrepancies and scattered data for similar systems in the literature.In general, the surfactant-cyclodextrin association is treated without reference to the kinetics of the process. However, there are several examples where the kinetics of the process can be investigated, in particular those where volumes of the CD cavity and surfactant (either the tail or in special cases the head group) are similar in magnitude.This will also be critically reviewed.

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Section: CDmentioning

confidence: 99%

The formation of host–guest complexes between surfactants and cyclodextrins

Valente

Söderman

2014

Advances in Colloid and Interface Science

183

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“…We now recognize that the change in absorbance depends on two factors; the concentration and the molar absorptivity of species in solution. Depending on whether the guest is nonabsorbing (silent) or not, we see that (18) and (24) could be applied to describe the change in absorbance if we define the change in molar absorptivity as ε HG = ε HG − ε H , where ε HG and ε H are the molar absorptivities of the complex and the host, respectively. When the guest is nonabsorbing, we obtain (27).…”

Section: Uv-vis Measurements Of 1 : 1 Equilibriamentioning

confidence: 99%

Binding Constants and Their Measurement

Thordarson

2012

Supramolecular Chemistry

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This chapter is concerned with how binding constants in supramolecular chemistry are determined. It is divided into three main sections. The first and largest section of this chapter details the key mathematical equations used to describe supramolecular equilibria, including common ones such as 1:1, 1:2, and dimerization as well as less frequently encountered 2:1, 2:2, and linear aggregation models. Details are also provided on how these equations are used with commonly used experimental techniques such as NMR, UV–vis, and fluorescence spectroscopy as well as calorimetry. The next section then discusses methods used for the determination of stoichiometry, including Job's method. The final section is concerned with data analysis, including model selection and comparison, global analysis, estimation of uncertainties, software consideration, and a brief review of selected software packages available for analyzing data from supramolecular titrations. Representative examples from the literature are also included to highlight the topics covered in this chapter.

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“…This effect is possibly due to electrostatic repulsion thereby w eakening the b inding o f the second sodium c a tio n .13 Sim ilar negative cooperativ ity b eh av io u r has been rep o rted earlier fo r rigid bis-benzo-15-crow n-5 d itopic h o st binding to sodium (a = 0.01-0.4 depending o n su b stitu en t). 19,20 T he a d d itio n o f K P F 6 to C O P V (7.1 x 10-7 M -1) shows different behavior. The fluorescence intensity (Fig.…”

Section: Resultsmentioning

confidence: 99%