The Raman non-coincidence effect of the 12CO stretching mode of liquid acetone in chemical and in isotopic mixtures

Musso, Maurizio; Giorgini, Maria Grazia; Torii, Hajime; Dorka, Roland; Schiel, Detlef; Asenbaum, Augustinus; Keutel, Dietmar; Oehme, K.-L.

doi:10.1016/j.molliq.2005.11.003

Cited by 24 publications

(38 citation statements)

References 60 publications

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“…The filled circles represent calculated nonzero values, although in panels a and b, the value for n = 2 is very close to zero. The structures of (PC) 4 Li + , (DEC) 4 Li + , (PC) 3 (DEC) 1 Li + , and (DEC) 3 Li + ClO 4 − (whose NCE values are indicated by arrows) are shown in the insets.The Journal of Physical Chemistry LettersLetter and νã niso = 1748 cm −1 ); and (3) both NCEs are reduced upon 1:1 mixing, but the former is reduced by no more than 50% (to 8 cm −1 ), as expected for the more dipolar species in a binary mixture 25,37,38. Upon solvation of LiClO 4 in liquid PC, rising of a shoulder band is seen in the isotropic Raman spectrum at 1810 cm −1 (although overlapped with the Fermi resonance band of the neat liquid) and in the anisotropic Raman spectrum at 1769 cm −1 , as shown inFigure 1a,b, similarly to the case of salt solvation in liquid acetone.…”

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confidence: 79%

Solvation Structure around the Li⁺ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Giorgini

Futamatagawa

Torii

et al. 2015

J. Phys. Chem. Lett.

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The solvation structure around the Li + ion in a mixed cyclic/linear carbonate solution, an important factor for the performance of lithium-based rechargeable batteries, is examined by measuring and analyzing the noncoincidence effect observed for the CO stretching Raman band. This technique has the advantage of perceiving relative distances and orientations of solvent molecules clustering around an ion in the first solvation shell and, hence, of developing information on the solvation structure along the wavenumber axis rather than along the intensity axis of the spectra. It is shown that, taking the solution of Li + ClO 4 − in the 1:1 mixed solvent of propylene carbonate (PC) and diethyl carbonate (DEC) as an example case, the Li + ion is preferentially solvated by PC molecules [primarily as (PC) 3 (DEC) 1 Li + ] and is totally protected from direct interaction (contact ion pairing) with the ClO 4 − ion. The solvation structures in neat PC and neat DEC solvents are also discussed.I on solvation is a central, and still an open, issue in many chemical, biochemical, and electrochemical processes. One of those important processes would be the functioning of lithium-based rechargeable batteries. 1−3 Their performance depends on the electrode materials and processes on the one hand and on the charge carrier concentration and mobility in the electrolyte solution on the other hand. With regard to the latter, high charge density of the Li + ion should be sufficiently stabilized, and at the same time, the electrolyte solution should have sufficiently high fluidity. A usual practice to make these two factors compatible is to employ a mixed solvent, consisting of a highly dipolar liquid such as a cyclic carbonate stabilizing the high charge density (but highly viscous) and a liquid of lower viscosity such as a linear carbonate (being less dipolar). Quite often ethylene or propylene carbonate (with dielectric constant ε = 65−90 and viscosity η ≅ 2.5 cP, abbreviated as EC and PC) is used for the former, and dimethyl, diethyl, or ethyl methyl carbonate (with ε ≅ 3 and η = 0.6−0.9 cP, abbreviated as DMC, DEC, and EMC) is used for the latter.The solvation structure around the Li + ion, especially that of the first solvation shell, has been suggested to be important for the interphase chemistry on the electrodes. 4−6 The use of a mixed solvent introduces a complexity in this. One controversial subject in this regard is the presence/absence of the preferential solvation and (if present) its nature for the Li + ion in a mixed cyclic/linear carbonate solution. 7−19 On the basis of electrospray ionization mass spectroscopy (ESI-MS), 7,8 it has been suggested that there is a strong preferential solvation for Li + in EC/EMC, with the Li + (EC) 2 species as the main ingredient. 7 The same type of preferential solvation (i.e., with a higher population of cyclic carbonate around the ion than in the bulk) has also been suggested in some NMR studies 9−11 but with a much larger total solvation number (≥6). 9,20 It has been argued that some...

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confidence: 79%

Solvation Structure around the Li⁺ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Giorgini

Futamatagawa

Torii

et al. 2015

J. Phys. Chem. Lett.

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“…This mutual orientation is also compatible with the near neighbour dipolar interaction resulting from the charge distribution on each acetone molecule. 36 The Coulomb interaction, at a contact distance, is about a factor of 6 Â 10 2 larger than the LennardJones interaction between the sites. However, when two acetone molecules are in this configuration, no other acetone molecule can come any closer in a favorable way.…”

Section: 32mentioning

confidence: 99%

“…Therefore, in the benzene-acetone mixtures, acetone molecules will tend to stay in segregated pockets, where they can randomly associate into dimers. 36 The internal energy in such pockets will be in average greater (more negative) than if the mixture was strictly random. So acetone association is energy bound.…”

Section: 32mentioning

confidence: 99%

Simple and complex disorder in binary mixtures with benzene as a common solvent

Požar

Seguier

Guerche

et al. 2015

Phys. Chem. Chem. Phys.

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Substituting benzene for water in computer simulations of binary mixtures allows one to study the various forms of disorder, without the complications often encountered in aqueous mixtures. In particular, we study the relationship between the local order generated by different types of molecular interactions and the nature of the global disorder, by analyzing the relationship between the concentration fluctuations and the correlation functions and the associated structure factors. Alkane-benzene mixtures are very close to ideal mixtures, despite appreciable short range shape mismatch interactions, acetone-benzene mixtures appear as a good example of regular mixtures, and ethanol-benzene mixtures show large micro-segregation. In the latter case, we can unambiguously demonstrate, unlike in the case of water, the appearance of domain-domain correlations, both in the correlation functions and the structure factor calculated in computer simulations. This finding helps to confirm the existence of a pre-peak in the structure factor associated with the micro-heterogeneity, which was speculated from several of our previous simulations of aqueous-alcohol mixtures. The fact that benzene as a solvent allows us to solve some of the problems that could not be solved with water points towards some of the particularities of water as a solvent, which we discuss herein. The concept of molecular emulsion put forward in our earlier work is useful in formulating these differences between water and benzene through the analogy with direct and inverse micellar aggregates.

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“…The acetone carbonyl stretch is a classic example of a system that exhibits a strong RNCE in the bulk liquid [109,110], with a shift on the order 5 cm À1 . However, two different studies have failed to find a VSFG signal from the carbonyl stretch of acetone at the liquid/vapour interface [13,111].…”

Section: Interpretation Of Vsfg Spectra In Terms Of the Properties Ofmentioning

confidence: 99%

Reexamining the interpretation of vibrational sum-frequency generation spectra

Rivera

Fourkas

2011

International Reviews in Physical Chemistry

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Vibrational sum-frequency generation (VSFG) has become a widely used technique for studying molecular orientation and intermolecular structure at interfaces. Due to the interfacial and vibrational selectivity of this technique, it can be used to probe molecular monolayers that are buried within bulk materials. Here, we present a critical review and examination of the assumptions that are generally used in the interpretation of VSFG spectra. This review focuses on three different aspects of VSFG spectroscopy. First, we examine the effect of dynamics (both reorientation and energy transfer) on the interpretation of VSFG spectra. Second, we consider whether (and under what circumstances) VSFG spectra cannot be interpreted solely in terms of the spectral properties of individual molecules. Third, we consider whether VSFG spectra obtained in different modes (frequency-domain, time-domain and broadband) should provide identical information. We conclude with a discussion of the challenges and opportunities provided by the revised viewpoint of VSFG that we present.

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The Raman non-coincidence effect of the 12CO stretching mode of liquid acetone in chemical and in isotopic mixtures

Cited by 24 publications

References 60 publications

Solvation Structure around the Li⁺ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Solvation Structure around the Li⁺ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Simple and complex disorder in binary mixtures with benzene as a common solvent

Reexamining the interpretation of vibrational sum-frequency generation spectra

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The Raman non-coincidence effect of the 12CO stretching mode of liquid acetone in chemical and in isotopic mixtures

Cited by 24 publications

References 60 publications

Solvation Structure around the Li+ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Solvation Structure around the Li+ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Simple and complex disorder in binary mixtures with benzene as a common solvent

Reexamining the interpretation of vibrational sum-frequency generation spectra

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Product

Resources

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Solvation Structure around the Li⁺ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect

Solvation Structure around the Li⁺ Ion in Mixed Cyclic/Linear Carbonate Solutions Unveiled by the Raman Noncoincidence Effect