Vibrational studies on the selective solvation of Na+ and ClO3− ions in dimethylformamide–formamide mixture

Alves, Wagner A.; Soto, Claudio A. Telléz; Hollauer, Eduardo; Faria, Roberto B.

doi:10.1016/j.saa.2005.02.044

Cited by 16 publications

(6 citation statements)

References 30 publications

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“…Here, it is interesting to note that the bands at 2250 and 2246 cm 1 are not significantly affected by dilution and such fact also has been observed in our recent work. 3, and the band at ca 1590 cm 1 , which is commonly assigned to the NH 2 bending in a local environment very similar to that in pure FA, is accompanied of another band at 1613 cm 1 adduct, since the NH 2 bending mode is less sensitive for interactions than the S O and C N stretching modes. 22,23 The formation of the FA-DMSO and FA-ACN adducts occurs owing to the presence of H-bond donor sites of FA (acidic center) and S O and C N functional groups (basic center) of DMSO and ACN, respectively.…”

Section: Resultsmentioning

confidence: 89%

Using Raman spectroscopy to investigate donor–acceptor reactions in the formamide/dimethylsulfoxide/acetonitrile system

Alves

Santos

2007

J Raman Spectroscopy

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Raman spectra of binary and ternary solvent systems in different concentrations were carried out. The mixtures containing equimolar quantities of dimethylsulfoxide (DMSO) and acetonitrile (ACN), or those in different compositions, do not show any spectral evidence for the formation of a Lewis acid-base adduct. On the contrary, the formamide (FA), DMSO and ACN mixtures exhibit new bands. In the S O stretching region, the band at 1025 cm −1 is assigned to the FA-DMSO adduct whereas, in the C N stretching region, the 2257 cm −1 band corresponds to the FA-ACN adduct. The positions of these two new bands in the present system are in agreement with our recent works. In addition, in the NH 2 bending region, the 1613 cm −1 band has been described as a mixture of both adducts. Quantitative analyses performed in the S O and C N stretching regions show that the association extent for the FA-DMSO adduct is greater than for the FA-ACN adduct, and this is in excellent agreement with the acid-base concepts commonly used to nonaqueous solvents. Preferential interactions between FA molecules as well as their dependence on the ternary mixture composition are also discussed. The results described here open up new possibilities to study the acid-base reactions nature involving FA adducts and can be useful for a better description of biological systems in which peptide groups have a special role.

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Section: Resultsmentioning

confidence: 89%

Using Raman spectroscopy to investigate donor–acceptor reactions in the formamide/dimethylsulfoxide/acetonitrile system

Alves

Santos

2007

J Raman Spectroscopy

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“…Thereafter, the sequestrated polar solvents interact with the polar head of AOT and weaken the HC‐AOT interaction. It is known that the non‐H‐bond donor solvents DMF and DMA have a large affinity for solvating cations, which can disrupt their weakly bulk associated structures . Therefore, DMF and DMA encapsulated inside AOT RMs could preferentially solvate the Na + counterions without interacting with the sulfonate group as reflected in the shifting shown for the HC absorption spectra.…”

Section: Resultsmentioning

confidence: 99%

Properties of AOT reverse micelle interfaces with different polar solvents

Luna

Correa

Silber

et al. 2016

J of Physical Organic Chem

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The behavior of polar solvents such as formamide, ethylene glycol, propylene glycol, glycerol, dimethylformamide (DMF), and dimethylacetamide (DMA), entrapped in n‐heptane/sodium 1,4‐bis‐2‐ethylhexylsulfosuccinate (AOT) reverse micelles (RMs) was investigated using absorption, emission, and the red edge excitation shift technique. We use the solvatochromism behavior of the hemycianine 4‐(4‐[dimethylamino]‐styryl)‐1‐methylpyridinium iodide (HC) to investigate the physicochemical properties such as micropolarity, microviscosity, and hydrogen bond (H‐bond) interaction in the non‐aqueous RMs. Our results demonstrate that AOT surfactant interacts through H‐bond with formamide, ethylene glycol, propylene glycol, and glycerol,and this interaction is responsible for weakening the electrostatic interaction between HC‐AOT when entrapped in n‐heptane/AOT RMs in absence of a polar solvent. On the other hand, when non‐H‐bond donor solvents (DMF and DMA) are incorporated inside the RMs, the structure of both pure solvents is destroyed upon encapsulation by the Na+‐DMF or Na+‐DMA interaction at Ws (Ws = [polar organic solvent]/[AOT]) ≤1.5. Our results show how the physicochemical properties, such as micropolarity, microviscosity, and H‐bond interaction, of non‐aqueous n‐heptane/AOT RMs interfaces can be dramatically changed by simply using different non‐aqueous polar solvent. Thus, these results can be very useful for employing these RMs, stabilizing enzymes, and using them as nanoreactors. Copyright © 2016 John Wiley & Sons, Ltd.

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“…With optimal addition of HCl (up to 0.6 mM), the reaction essentially proceeds in a similar fashion, except for the delayed induction time (50 min), with peaks at around 590 and 905 nm (Figures b and S1), implying that both the proton and the chloride ion of HCl play a significant role. The proton is preferentially solvated by DMF, − whereas the chloride ions maintain the equilibrium concentration of AuCl 4 – ions, thus decreasing the net nucleation rate. To separate the roles played by proton and chloride, we replace HCl with equimolar amounts of HNO 3 and KCl (Figures S2 and S3).…”

Section: Resultsmentioning

confidence: 99%

Precursor-Driven Nucleation and Growth Kinetics of Gold Nanostars

Kedia

Kumar

2012

J. Phys. Chem. C

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Recently, seed-mediated approach has been widely utilized for synthesizing monodisperse gold nanostars well-known for plasmonic and sensing applications. Herein, we report a single step seedless/templateless organic synthesis procedure for the complex 3D gold nanostars with a high degree of size/shape control, involving the complexation of polyvinylpyrrolidone (PVP) in polar solvent N,N-dimethylformamide (DMF) and their reduction of AuCl4 – ions along with hydrochloric acid (HCl) as an effective mediator. On the basis of the kinetic optical absorption and Fourier transform infrared (FTIR) spectroscopy measurements, a convenient ligand exchange mechanism has been proposed for the first time to the best of our knowledge to understand the evolution of these complex shaped gold nanostructures. The coordination interaction among PVP and DMF as well as PVP–DMF–AuCl4 has been identified as the major driving factors influencing the temporal evolution of the size/shape-controlled gold nanostars.

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Vibrational studies on the selective solvation of Na+ and ClO3− ions in dimethylformamide–formamide mixture

Cited by 16 publications

References 30 publications

Using Raman spectroscopy to investigate donor–acceptor reactions in the formamide/dimethylsulfoxide/acetonitrile system

Using Raman spectroscopy to investigate donor–acceptor reactions in the formamide/dimethylsulfoxide/acetonitrile system

Properties of AOT reverse micelle interfaces with different polar solvents

Precursor-Driven Nucleation and Growth Kinetics of Gold Nanostars

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