Dielectric response and collective dynamics of acetonitrile

Stoppa, Alexander; Nazet, Andreas; Buchner, Richard; Thoman, Andreas; Walther, Markus

doi:10.1016/j.molliq.2015.03.045

Cited by 42 publications

(32 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, fits for these solutions were repeated assuming an additional contribution at ∼1 GHz ( S 3 , τ 3 in Table S5). Despite the small values resulting from these 6D fits for the amplitudes S 3 and S 4 , rapid convergence was achieved and the fit quality (in terms of χ 2 , see ref (25)) even slightly improved. On the basis of the data for SDS 57 and tetraalkylammonium halides, 55 we tentatively assign the mode associated with the thus obtained relaxation time of τ 3 ≈ 80–200 ps to retarded water molecules interacting with the micelles and that with τ 4 ≈ 14–40 ps to H 2 O hydrating free monomers.…”

Section: Resultsmentioning

confidence: 99%

Insight into the Hydration of Cationic Surfactants: A Thermodynamic and Dielectric Study of Functionalized Quaternary Ammonium Chlorides

et al. 2019

Self Cite

View full text Add to dashboard Cite

Hydrophobic interactions are one of the main thermodynamic driving forces in self-assembly, folding, and association processes. To understand the dehydration-driven solvent exposure of hydrophobic surfaces, the micellization of functionalized decyldimethylammonium chlorides, XC 10 Me 2 N + Cl – , with a polar functional group, X = C 2 OH, C 2 OMe, C 2 OC 2 OMe, C 2 OOEt, together with the “reference” compound decyltrimethylammonium chloride, C 10 Me 3 N + Cl – , was investigated in aqueous solution by density measurements, isothermal titration calorimetry (ITC), and dielectric relaxation spectroscopy (DRS). From the density data, the apparent molar volumes of monomers and micelles were estimated, whereas the ITC data were analyzed with the help of a model equation, yielding the thermodynamic parameters and aggregation number. From the DRS spectra, effective hydration numbers of the free monomers and micelles were deduced. The comprehensive analysis of the obtained results shows that the thermodynamics of micellization are strongly affected by the nature of the functional group. Surprisingly, the hydration of micelles formed by surfactant cations with a single alkyl chain on quaternary ammonium is approximately the same, regardless of the alkyl chain length or functionalization of the headgroup. However, notable differences were found for the free monomers where increasing polarity lowers the effective hydration number.

show abstract

Section: Resultsmentioning

confidence: 99%

Insight into the Hydration of Cationic Surfactants: A Thermodynamic and Dielectric Study of Functionalized Quaternary Ammonium Chlorides

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…(36) and (37), evaluated using the data in Table V. [47][48][49][50][51] For the experiments in Fig. 2(a).…”

Section: Ion-induced Hrsmentioning

confidence: 99%

What is measured by hyper-Rayleigh scattering from a liquid?

Rodriquez

Shelton

2018

The Journal of Chemical Physics

View full text Add to dashboard Cite

Polarization and angle dependence of hyper-Rayleigh scattering (HRS) measured for liquid acetonitrile and dimethyl sulfoxide (DMSO) is analyzed in terms of contributions from randomly oriented molecules and additional contributions produced during intermolecular collisions and induced by the electric field of dissolved ions. All three contributions show the effect of long-range correlation, and the correlation functions are determined using the HRS observations combined with the results of molecular dynamics simulations. HRS from acetonitrile is polarized transverse to the scattering vector. This is due to long-range molecular orientation correlation produced by the dipole-dipole interaction, and correlation at distances r > 100 nm must be included to account for the HRS observations. Analysis of the HRS measurements for acetonitrile determines the length scale a = 0.185 nm for the long-range longitudinal and transverse orientation correlation functions B=-2B=a/r. Transverse polarized collision-induced HRS is also observed for acetonitrile, indicating long-range correlation of intermolecular modes. Strong longitudinal HRS is induced by the radial electric field of dissolved ions in acetonitrile. For DMSO, the angle between the molecular dipole and the vector part of the first hyperpolarizability tensor is about 100°. As a result, HRS from the randomly oriented molecules in DMSO is nearly unaffected by dipole correlation, and ion-induced HRS is weak. The strong longitudinal polarized HRS observed for DMSO is due to the collision-induced contribution, indicating long-range correlation of intermolecular modes. The HRS observations require correlation that has r long-range asymptotic form, for molecular orientation and for intermolecular vibration and libration, for both acetonitrile and DMSO.

show abstract

“….5, Havriliak-Negami equations or their simplified variants and the resulting fits and their parameters were scrutinized as described in detail elsewhere. 35,36 It was found that all solution spectra were best fitted by the sum of four Debye equations (the 4D model), i.e.…”

Section: Andmentioning

confidence: 99%

Hydration and self-aggregation of a neutral cosolute from dielectric relaxation spectroscopy and MD simulations: the case of 1,3-dimethylurea

Agieienko

Horinek

Buchner

2017

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

The influence of the amphiphile 1,3-dimethylurea (1,3-DMU) on the dynamic properties of water was studied using dielectric relaxation spectroscopy. The experiment provided evidence for substantial retardation of water reorientation in the hydration shell of 1,3-DMU, leading to a separate slow-water relaxation in addition to contributions from bulk-like and fast water as well as from the solute. From the amplitudes of the resolved water modes effective hydration numbers were calculated, showing that each 1,3-DMU molecule effectively freezes the reorientation of 1-2 water molecules. Additionally, a significant amount of solvent molecules, decreasing from ∼39 at infinite dilution to ∼3 close to the solubility limit, is retarded by a factor of ∼1.4 to 2.3, depending on concentration. The marked increase of the solute amplitude indicates pronounced parallel dipole alignment between 1,3-DMU and its strongly bound HO molecules. Molecular dynamics (MD) simulations of selected solutions revealed a notable slowdown of water rotation for those solvent molecules surrounding the methyl groups of 1,3-DMU and strong binding of ∼2HO by the hydrophilic carbonyl group, corroborating thus the experimental results. Additionally, the simulations revealed 1,3-DMU self-aggregates of substantial lifetime.

show abstract

Dielectric response and collective dynamics of acetonitrile

Cited by 42 publications

References 37 publications

Insight into the Hydration of Cationic Surfactants: A Thermodynamic and Dielectric Study of Functionalized Quaternary Ammonium Chlorides

Insight into the Hydration of Cationic Surfactants: A Thermodynamic and Dielectric Study of Functionalized Quaternary Ammonium Chlorides

What is measured by hyper-Rayleigh scattering from a liquid?

Hydration and self-aggregation of a neutral cosolute from dielectric relaxation spectroscopy and MD simulations: the case of 1,3-dimethylurea

Contact Info

Product

Resources

About