Dielectric and viscosity studies of the principal relaxation process of liquid 1-alkanols and their solutions

Mandal, Humayun; Frood, D. G.; Saleh, Mohammad A.; Morgan, Billy K.; Walker, S.

doi:10.1016/0301-0104(89)87175-7

Cited by 24 publications

(24 citation statements)

References 32 publications

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“…It should be noted that the indicated shift of the reaction path is caused by the stronger viscosity dependence on τ L of alcohols; as indicated by τ L (η) ∝ η α with the exponent α that is larger than 1 ( e.g. , α = 1.24 for ethanol). , We have observed the similar shift behavior for the excited-state intramolecular CT formation in 4,4‘-diaminodiphenyl sulfone (DAPS) in alcohols 2 Power Law Parameter, α solvent αsolvent α ethanol 0.71 a 1-butanol 0.31, a 0.32 b 1-propanol 0.44 a 1-octanol 0.35 a a Obtained from the yield ratio.…”

Section: Discussionsupporting

confidence: 52%

“…It should be noted that the indicated shift of the reaction path is caused by the stronger viscosity dependence on τ L of alcohols; as indicated by τ L (η) ∝ η R with the exponent R that is larger than 1 (e.g., R ) 1.24 for ethanol). 28,29 We have observed the similar shift behavior for the excited-state intramolecular CT formation in 4,4′-diaminodiphenyl sulfone (DAPS) in alcohols. 30 On the other hand, in Figure 7, the rate constant of the CT formation (k CT ) of DMATP in alcohols, which is defined by the inverse of the average survival time of the LE state (τ a -1 ), is plotted against solvent viscosity.…”

Section: Discussionmentioning

confidence: 63%

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High-Pressure Studies on the Excited-State Intramolecular Charge Transfer of 4-(N,N-Dimethylamino)triphenylphosphine in Alcohols

1996

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The influence of solvent viscosity on the intramolecular charge-transfer (CT)-state formation in the excited S 1 state for 4-(N,N-dimethylamino) triphenylphosphine (DMATP) in alcohol solvents has been investigated by measuring the steady-state and time-resolved fluorescence spectra at high pressures. The kinetic mechanism of the intramolecular CT reaction has been examined as a function of solvent shear viscosity. In the lower viscosity region the reaction is controlled by the solvent relaxation. With increasing pressure, the reaction path shifts toward the "high-viscosity regime" in which the molecule moves along the nonrelaxed path on the free energy surface. The viscosity dependence of R = 0.33, where R is the power law parameter, can be interpreted as the extreme value in which the reaction is controlled by the dynamic solvent effect due to intrinsic collisional interaction of barrier crossing. The coupling between the intramolecular CT-state formation dynamics of DMATP and the solvent relaxation dynamics is discussed.

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Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 63%

High-Pressure Studies on the Excited-State Intramolecular Charge Transfer of 4-(N,N-Dimethylamino)triphenylphosphine in Alcohols

1996

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“…Many data have been measured just for this work (specifically for the water–methanol solutions ( Figure 1 a) at

for

K; in the water–glycerol case ( Figure 1 b), the measured concentrations are

for

K). All other data come from the literature: for the methanol solutions, References [ 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ] and, for those of glycerol, References [ 48 , 57 , 58 , 59 , 60 , 61 ]. For water, the reported data come from different experimental approaches: the bulk water data (reported as fully blue symbols) come from NMR experiments [ 62 , 63 ]; fused amorphous water (dark blue squares [ 22 ]) and MCM confined (actually measured NMR data are illustrated as dark blue squares and as open blue triangles [ 32 ]; and finally, the dielectric relaxation data [ 64 ] are illustrated as blue open circles).…”

Section: Data and Data Analysismentioning

confidence: 99%

Hydrophilic and Hydrophobic Effects on the Structure and Themodynamic Properties of Confined Water: Water in Solutions

Mallamace

Chen

et al. 2021

IJMS

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NMR spectroscopy is used in the temperature range 180–350 K to study the local order and transport properties of pure liquid water (bulk and confined) and its solutions with glycerol and methanol at different molar fractions. We focused our interest on the hydrophobic effects (HE), i.e., the competition between hydrophilic and hydrophobic interactions. Nowadays, compared to hydrophilicity, little is known about hydrophobicity. Therefore, the main purpose of this study is to gain new information about hydrophobicity. As the liquid water properties are dominated by polymorphism (two coexisting liquid phases of high and low density) due to hydrogen bond interactions (HB), creating (especially in the supercooled regime) the tetrahedral networking, we focused our interest to the HE of these structures. We measured the relaxation times (T1 and T2) and the self-diffusion (DS). From these times, we took advantage of the NMR property to follow the behaviors of each molecular component (the hydrophilic and hydrophobic groups) separately. In contrast, DS is studied in terms of the Adam–Gibbs model by obtaining the configurational entropy (Sconf) and the specific heat contributions (CP,conf). We find that, for the HE, all of the studied quantities behave differently. For water–glycerol, the HB interaction is dominant for all conditions; water–methanol, two different T-regions above and below 265 K are observable, dominated by hydrophobicity and hydrophilicity, respectively. Below this temperature, where the LDL phase and the HB network develops and grows, with the times and CP,conf change behaviors leading to maxima and minima. Above it, the HB becomes weak and less stable, the HDL dominates, and hydrophobicity determines the solution.

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“…Previous studies have been concerned with mixing alcohols with other alcohols or with other liquids, looking for effects of the interaction with these other molecules and of the dilution of the alcohol [4,[7][8][9]. To our knowledge alcohols have not been mixed earlier with aerosils.…”

Section: Introductionmentioning

confidence: 95%

“…The dielectric spectra typically show three processes, and especially the interpretation of the slowest and strongest process is a point of discussion. We will not elaborate on this subject, but refer the reader to a number of books and papers containing discussion, recent research efforts and further references [4][5][6][7][8][9]. This paper will only consider the slowest relaxation process.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of alcohols dispersed with aerosils

Glorieux

Thoen

2007

Journal of Non-Crystalline Solids

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Dielectric and viscosity studies of the principal relaxation process of liquid 1-alkanols and their solutions

Cited by 24 publications

References 32 publications

High-Pressure Studies on the Excited-State Intramolecular Charge Transfer of 4-(N,N-Dimethylamino)triphenylphosphine in Alcohols

High-Pressure Studies on the Excited-State Intramolecular Charge Transfer of 4-(N,N-Dimethylamino)triphenylphosphine in Alcohols

Hydrophilic and Hydrophobic Effects on the Structure and Themodynamic Properties of Confined Water: Water in Solutions

Dynamics of alcohols dispersed with aerosils

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