On the characterization of NaDEHP/n-heptane nonaqueous reverse micelles: The effect of the polar solvent

The behavior of two polar solvents, ethylene glycol (EG) and dimethylformamide (DMF), entrapped in sodium bis-(2-ethylhexyl) phosphate (NaDEHP)/n-heptane reverse micelles (RMs) was investigated using dynamic light scattering (DLS), molecular probe absorption and FT-IR spectroscopy. DLS results reveal the formation of RMs containing EG and DMF as a polar component. To the best of our knowledge this is the first report where both polar solvents are entrapped by the NaDEHP surfactant to effectively create RMs. We use the solvatochromism behavior of the molecular probe, 1-methyl-8-oxyquinolinum betaine (QB), and FT-IR spectroscopy to investigate the physicochemical properties of the non-aqueous RMs. Our results demonstrate that the NaDEHP surfactant interacts through hydrogen bonds with EG at the EG/NaDEHP interface and this interaction is responsible for destroying the bulk structure of pure solvent EG when entrapped in NaDEHP RMs. On the other hand, when DMF is incorporated inside the RMs the bulk structure of DMF is destroyed upon encapsulation by the Na-DMF interaction at the DMF/NaDEHP interface. Our results are completely different than the one observed for DMF/n-heptane/AOT. Our results show how the physicochemical properties, such as micropolarity, microviscosity and hydrogen bond interaction, of nonaqueous NaDEHP/n-heptane RMs interfaces can be dramatically changed by simply using different non-aqueous polar solvents. Thus, these results can be very useful to employ these novel RMs as nanoreactors since the dimensions of the RMs are around 10 to 20 nm.Fil: Quintana Lazópulos, Silvina Soledad. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Moyano, Fernando. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Supramolecular Assemblies Obtained by Mixing Different Cyclodextrins and AOT or BHDC Reverse Micelles

In this contribution we show the effect of the surfactant polar head and the external solvent on the incorporation of different cyclodextrins (CDs) {α-CD, β-CD, γ-CD, decenylsuccinyl-β-CD (Mod-β-CD), and hydroxypropyl-β-CD (hp-β-CD)} in different reverse micelles (RMs) {benzene/sodium 1,4-bis(2-ethylhexyl) sulfosuccinate(AOT)/water, and benzene/benzyl-n-hexadecyldimethylammonium chloride (BHDC)/water} and compare them with previous results obtained in n-heptane/AOT/water RMs. To investigate the different systems, we have used UV–vis spectrophotometry, induced circular dichroism spectroscopy (ICD), and the achiral molecular probe methyl orange (MO). The results show dramatic differences changing the external solvent and the surfactant, which are explained by considering the differences in the RMs interface composition, the water–surfactant interaction, and the CDs’ location in the different media investigated. None of the CDs were incorporated into the benzene/AOT/water RMs at any [H2O]/[surfactant] ratio studied (W0) whereas it was previously shown that Mod-β-CD and hp-β-CD could be included in n-heptane/AOT/water RMs. However, all of the CDs are incorporated in benzene/BHDC/water RMs at W0 > 10 and hp-β-CD is dissolved even at W0 = 0. Different from what was found in n-heptane/AOT RMs, in BHDC RMs MO showed ICD signals with two different CDs: Mod-β-CD and hp-β-CD. The results are explained by considering the known difference in the interfacial water structure for AOT and BHDC RMs and the electron-rich region on the secondary hydroxyl (wider side of the CDs), which helps to solubilize all CDs in BHDC. This study shows that chiral cyclodextrin could be available for a guest in an organic medium such as the RMs. Therefore we have created a potentially powerful nanoreactor with two different confined regions in the same aggregate: the polar core of the RMs and the chiral hydrophobic cavity of cyclodextrin.Fil: Silva, Oscar Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto; ArgentinaFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto; ArgentinaFil: Hoyos, Maria Rita Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Fernández, Mariana Adela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentin

How TOPO affects the interface of the novel mixed water/AOT:TOPO/n-heptane reverse micelles: dynamic light scattering and Fourier transform infrared spectroscopy studies

In this work we report for the first time the formation of two reverse micelle (RM) media produced by the nonionic surfactant tri-n-octyl phosphine oxide (TOPO) in n-heptane and the one produced by mixing the anionic sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT) with different TOPO contents dissolved in n-heptane. Dynamic light scattering (DLS) experiments reveal the formation of water/TOPO/n-heptane RMs (TOPO RMs) and water/AOT:TOPO/n-heptane RMs (mixed RMs) since the droplet sizes increase as the water content increases. The addition of TOPO to the system at constant W0 (W0 = [water]/([AOT] + [TOPO])) causes the droplet sizes of mixed RMs to decrease compared with the AOT RMs. In addition, the decrease is larger when the water content is low (W0 = 0.5) but the effect is negligible at the maximum W0 value analyzed (W0 = 2). These results are not expected for mixtures of different nonionic surfactants with AOT and were explained considering the unique TOPO structure. Thus, at W0 = 0.5, we suggest that the percentage of TOPO molecules at the mixed RM interface is higher than those corresponding to the bulk solution. On the other hand, at W0 = 2 the RM interface is comprised mainly of AOT molecules. The FT-IR experiments performed by monitoring monodeuterated water frequency (νOD) in TOPO RMs show bound and “bulk-like” water structure even at very low water content. On the other hand, for mixed RMs the water structure depends on the water content. At low W0 value, there are two kinds of water molecules, and at W0 value around 2 only bound water exists. The Fourier transform infrared (FT-IR) experiments performed on the symmetric (νsSO3) and asymmetric (νaSO3) sulfonate stretching bands of AOT reveal the existence of a strong Na+˙TOPO complex in the mixed RMs. The results show that adding TOPO to form mixed surfactant RMs with AOT reduces their size, changes the nature of water to have a “bulk-like” character and diminishes the ion pairing of the sulfonate group with Na+.Fil: Odella, Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Falcone, Ruben Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Chessa, Juana Josefa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Correa, Nestor Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentin

More evidence on the control of reverse micelles sizes: combination of different techniques as a powerful tool to monitor AOT reversed micelles properties

In this work, we have investigated the behavior of 4-aminophthalimide (4-AP) in solvent mixtures of ethyl lactate (EL)− water and EL−n-heptane and in reversed micelles (RMs) media made of EL−water/sodium 1,4-bis(2-ethylhexyl)- sulfosuccinate (AOT)/n-heptane. We have used dynamics light scattering (DLS) and absorption, steady-state and time-resolved emission (TRES) techniques. 4-AP is a very interesting and unique molecule used to study preferential solvation in water mixtures since its emission profile changes dramatically when its sphere shell is solvated by water molecules. Thus, in homogeneous media 4-AP is strongly solvated by water in the EL−water mixture and by EL in the EL−n-heptane mixture, results that show the importance of the hydrogen bonding in the 4-AP solvation. We were motivated by this feature of 4-AP and have used it to monitor properties in AOT RMs. Thus, we use 4-AP spectroscopic behavior in conjunction with DLS technique to reveal the location of each polar solvent of the mixture encapsulated within the RMs media. We found that in the EL−water/ AOT/n-heptane RMs the results strongly depend on the amount of water dissolved. Below W0 = [water]/[AOT] = 5, there are no reversed micelles and EL, water, AOT and n-heptane forms a nonstructured mixture. For W0 values between 5 and 10, the droplet sizes are independent of the EL content because of its strong intermolecular interactions forms an EL polar core and only water is found at the interface. For W0 values higher than 10, the droplets size increase with the EL content and EL molecules are detected at the AOT RMs interface. We inferred that the RMs sizes will change only if the polar solvent encapsulated interacts with the interface changing the surfactant packing parameter. Then, we can assume that it is possible to create RMs with solvents that do not interact with the interface but can be encapsulated in the polar core. These results, give evidence that expand the knowledge about which are the factors that determine when RMs droplet sizes changes with the polar solvent content, giving insights that will help to control the sizes of the AOT RMs. This will open diverse avenues since RMs are interesting nanoreactors for heterogeneous chemistry, templates for nanoparticles and models for electron transfer reaction that happens in membranes.Fil: Durantini, Andres Matías. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Electron donor ionic liquids entrapped in anionic and cationic reverse micelles. Effects of the interface on the ionic liquid–surfactant interactions

The behavior of two ionic liquids (ILs) with high electron donor ability such as 1-butyl-3-methylimidazolium trifluoromethanesulfonate (bmimTfO) and 1-butyl-3-methylimidazolium trifluoroacetate (bmimTfA) entrapped in anionic and cationic reverse micelles (RMs) was investigated using dynamic light scattering (DLS) and FT-IR spectroscopy. The systems studied were chlorobenzene/sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/bmimTfO, chlorobenzene/AOT/bmimTfA, chlorobenzene/benzyl-n-hexadecyldimethylammonium chloride (BHDC)/bmimTfO and chlorobenzene/BHDC/bmimTfA. DLS results reveal the formation of RMs containing bmimTfO and bmimTfA as polar components since the droplet size values increase as Ws (Ws = [IL]/[surfactant]) increases. To the best of our knowledge this is the first report where it is shown that both ILs are entrapped by AOT and BHDC surfactants to effectively create RMs. Furthermore, it is shown that the RMs consist of discrete spherical and non-interacting droplets of IL stabilized by the surfactants. The larger droplet size values and the larger changes obtained for bmimTfO entrapped in AOT and BHDC RMs in comparison with those for bmimTfA in both RMs can be explained considering the different IL–surfactant interactions. The FT-IR results suggest that the ionic interactions (with the surfactant polar head groups, surfactant counterions or with the IL counterions) are substantially modified upon confinement. These interactions produce segregation of ILs’s ions altering the composition of the RM interfaces. These facts show the versatility of this kind of organized systems to alter the ionic organization, information that can be very important if these media are used as nanoreactors because unique microenvironments can be easily created simply changing the RM components and Ws.Fil: Blach Vargas, Diana. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The use of two non-toxic lipophilic oils to generate environmentally friendly anionic reverse micelles without cosurfactant. Comparison with the behavior found for traditional organic non-polar solvents

In this work two different non-toxic solvents/sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/water reverse micelles (RMs) have been investigated by dynamic (DLS) and static (SLS) light scattering techniques. Methyl laurate (ML) and isopropyl myristate (IPM) were used as external non-polar solvents to formulate the AOT RMs without cosurfactant. DLS results reveal the formation of IPM and ML AOT RMs containing water as a polar component since the droplet sizes values increase as the W0 values increase. To the best of our knowledge this is the first report where ML is used to formulate AOT RMs. The droplets size values, the maximum amount of water solubilized and the aggregation numbers (Nagg, determined by SLS) of both AOT RMs are dissimilar considering the chemical structure of the external solvents and they can be explained taking into account the different non-polar solvent penetration to the interface. The results suggest that IPM penetrate more the interface than ML in AOT RMs, diminishing the interdroplets interactions and producing RMs with smaller sizes and Nagg than ML/AOT. The higher viscosity and polarity of IPM in comparison with ML promotes the interface penetration. Thus, the penetration of IPM into the interface is higher than ML, making the interface of IPM/AOT RMs more rigid and, in consequence with smaller droplets sizes values. Finally, a peculiar comparable behavior (droplets size, maximum amount of water solubilized and Nagg) between n-heptane and ML AOT RMs and benzene and IPM AOT RMs was observed. These results present a very promissory field since that the unique properties of the alkanes/AOT/water RMs can be obtained using non-toxic lipophilic oils and, in the same way the opportunity to formulate environmentally friendly AOT RMs.Fil: Girardi, Valeria Romina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Chessa, Juana Josefa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Correa, Nestor Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Falcone, Ruben Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentin

Effect of the Cationic Surfactant Moiety on the Structure of Water Entrapped in Two Catanionic Reverse Micelles Created from Ionic Liquid-Like Surfactants

The behavior of water entrapped in reverse micelles (RMs) formed by two catanionic ionic liquid-like surfactants, benzyl-n-hexadecyldimethylammonium 1,4-bis-2-ethylhexylsulfosuccinate (AOT-BHD) and cetyltrimethylammonium 1,4-bis-2-ethylhexylsulfosuccinate (AOT-CTA), was investigated by using dynamic (DLS) and static (SLS) light scattering, FTIR, and 1H NMR spectroscopy techniques. To the best of our knowledge, this is the first report in which AOT-CTA has been used to create RMs and encapsulate water. DLS and SLS results revealed the formation of RMs in benzene and the interaction of water with the RM interface. From FTIR and 1H NMR spectroscopy data, a difference in the magnitude of the water–catanionic surfactant interaction at the interface is observed. For the AOT-BHD RMs, a strong water–surfactant interaction can be invoked whereas for AOT-CTA this interaction seems to be weaker. Consequently, more water molecules interact with the interface in AOT-BHD RMs with a completely disrupted hydrogen-bond network, than in AOT-CTA RMs in which the water structure is partially preserved. We suggest that the benzyl group present in the BHD+ moiety in AOT-BHD is responsible for the behavior of the catanionic interface in comparison with the interface created in AOT-CTA. These results show that a simple change in the cationic component in the catanionic surfactant promotes remarkable changes in the RMs interface with interesting consequences, in particular when using the systems as nanoreactors.Fil: Villa Zabala, Cristian Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Chessa, Juana Josefa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Correa, Nestor Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Falcone, Ruben Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentin

PRODAN dual emission feature to monitor BHDC interfacial properties changes with the external organic solvent composition

We have investigated the water/benzyl-n-hexadecyldimethylammonium chloride (BHDC)/n-heptane:benzene reverse micelles (RMs) interfaces properties using 6-propionyl- 2-(N,N-dimethyl)aminonaphthalene, PRODAN, as molecular probe. We have used absorption and emission (steady-state and time-resolved) spectroscopy of PRODAN to monitor the changes in the RMs interface functionalities upon changing the external organic solvent blend. We demonstrate that PRODAN is a useful probe to investigate how the external solvent composition affects the micelle interface properties. Our results show that changes in the organic solvent composition in water/BHDC/n-heptane:benzene RMs have a dramatic effect on the photophysics of PRODAN. Thus, increasing the aliphatic solvent content over the aromatic one produces PRODAN partition and PRODAN intramolecular electron transfer (ICT) processes. Additionally, the water presence in these RMs makes the PRODAN ICT process favored with the consequent decreases in the LE emission intensity and a better definition of the charge transfer (CT) band. All this evidence suggests that the benzene molecules are expelled out of the interface, and the water−BHDC interactions are stronger with more presence of water molecules in the polar part of the interface. Thus, we demonstrate that a simple change in the composition of the external phase promotes remarkable changes in the RMs interface. Finally, the results obtained with PRODAN together with those reported in a previous work in our lab reveal that the external phase is important when trying to control the properties of RMs interface. It should be noted that the external phase itself, besides the surfactant and the polar solvent sequestrated, is a very important control variable that can play a key role if we consider smart application of these RMs systems.Fil: Agazzi, Federico Martin. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez, Javier. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Characterization of multifunctional reverse micelles' interfaces using hemicyanines as molecular probes: I. effect of the hemicyanines' structure

In this work, we report the behavior of two different hemicyanines, trans-4-[4-(dimethylamino)styryl]-Nmethylpyridinium iodide (HC) and 4-[4-(dihexadecylamino)styryl]-N-methylpyridinium iodide (DIA), in water/ sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/benzene reverse micelles media using absorption and emission spectroscopy in addition to the steady-state and time-resolved fluorescence emission techniques. Our results show that the AOT reverse micelles interface has the nontrivial deaggregation property, a result that may have potential application for the preparation of dye lasers, which require a noninteracting monomeric form of the dye. Also, we show that the water interacts with a different region of the AOT moiety depending on the external organic solvent used and, in addition, we also present a nice, simple, and noteworthy method that helps to examine the presence or the absence of organized media. In conclusion, our results show that HC and DIA are powerful dyes to characterize simultaneously different interfaces' properties as they can be used to sense, at the same time, fluidity and specific interactions at the interface. These results are important because those properties are the key for molecular recognition.Fil: Moyano, Fernando. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Quintana, Silvina S.. Universidad Nacional de Río Cuarto; ArgentinaFil: Falcone, Ruben Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Ionic Liquids Entrapped in Reverse Micelles as Nanoreactors for Bimolecular Nucleophilic Substitution Reaction. Effect of the Confinement on the Chloride Ion Availability

In this work was explored how the confinement of two ionic liquids (ILs), 1-butyl-3-methylimidazolium chloride (bmimCl) and 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4), inside toluene/benzyl-n-hexadecyldimethylammonium chloride (BHDC) reverse micelles (RMs) affects the Cl– nucleophilicity on the bimolecular nucleophilic substitution (SN2) reaction between this anion and dimethyl-4-nitrophenylsulfonium trifluoromethanesulfonate. The results obtained show that, upon confinement, the ionic interactions between the ILs with the cationic surfactant polar head group and the surfactant counterion modify substantially the performance of both ILs as solvents. In toluene/BHDC/bmimCl RMs, the Cl– interacts strongly with bmim+ (and/or BHD+) in such a way that its nucleophilicity is reduced in comparison with neat IL. In toluene/BHDC/bmimBF4 RMs, an ionic exchange equilibrium produces segregation of bmim+ and BF4– ions, changing the composition of the RMs interface and affecting dramatically the Cl– availability. These results show the versatility of this kind of organized system to alter the ionic organization and influence on reaction rate when used as nanoreactors.Fil: Blach Vargas, Diana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Pessêgo, Marcia. Universidad de Santiago de Compostela; España. Universidade do Algarve; PortugalFil: Chessa, Juana Josefa. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Correa, Nestor Mariano. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Garcia Rio, Luis. Universidad de Santiago de Compostela; EspañaFil: Falcone, Ruben Dario. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentin