Excess spectroscopy and its applications in the study of solution chemistry

Zhang, Yaqin; Wu, Zhiwei; Wang, Yaqian; He, Hongyan; Yu, Zhi‐Wu

doi:10.1515/pac-2020-0107

Cited by 42 publications

(29 citation statements)

References 97 publications

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“…For each IR spectrum, excess spectroscopy analysis was performed using the method as described elsewhere [ 10 , 82 , 83 ]. Briefly, excess absorption is defined as the residual between the absorption of a mixture and that of an ideal mixture:

where

and

are the absorption coefficients of the real mixture and ideal mixture, respectively.…”

Section: Methodsmentioning

confidence: 99%

The Structures of ZnCl2-Ethanol Mixtures, a Spectroscopic and Quantum Chemical Calculation Study

Kalhor

Wang

2021

Molecules

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We report in this article the structural properties, spectral behavior and heterogeneity of ZnCl2-ethanol (EtOH) mixtures in a wide-composition range (1:3 to 1:14 in molar ratios), using ATR-FTIR spectroscopy and quantum chemical calculations. To improve the resolution of the initial IR spectra, excess spectroscopy and two-dimensional correlation spectroscopy were employed. The transformation process was suggested to be from EtOH trimer and EtOH tetramer to EtOH monomer, EtOH dimer and ZnCl2-3EtOH complex upon mixing. The theoretical findings showed that increasing the content of EtOH was accompanied with the flow of negative charge to ZnCl2. This led to reinforcement of the Zn←O coordination bonds, increase of the ionic character of Zn‒Cl bond and weakening and even dissociation of the Zn‒Cl bond. It was found that in some of the ZnCl2-EtOH complexes optimized at the gas phase or under the solvent effect, there existed hydroxyls with a very special interactive array in the form of Cl‒Zn+←O‒H…Cl−, which incredibly red-shifted to wavenumbers <3000 cm−1. This in-depth study shows the physical insights of the respective electrolyte alcoholic solutions, particularly the solvation process of the salt, help to rationalize the reported experimental results, and may shed light on understanding the properties of the deep eutectic solvents formed from ZnCl2 and an alcohol.

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where

and

are the absorption coefficients of the real mixture and ideal mixture, respectively.…”

Section: Methodsmentioning

confidence: 99%

The Structures of ZnCl2-Ethanol Mixtures, a Spectroscopic and Quantum Chemical Calculation Study

Kalhor

Wang

2021

Molecules

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“…Currently, researchers mainly study the kinetic processes of forming and breaking HBs by spectroscopic methods (including IR and NMR). Examples include the following: nonideality and ionic clusters in ILs have been thoroughly studied by IR spectroscopy, 184 Tokmakoff et al revealed the unique vibration potential of the HF system in water and differentiated hydrogen bonding from chemical bonding via femtosecond IR technology, 64 and Hunger et al reported that the time scale of the vibrational spectrum of the N–H bond in [C 2 H 5 NH 3 ][NO 3 ] ranges from femtoseconds to picoseconds, indicating the Z-bond-induced complex movement of ions. 186 How to quickly detect the disruption of the Z-bond or the separation of cation–anion pairs remains a major challenge.…”

Section: Opportunities and Future Challenges Of Z-bonds And Quasi-liq...mentioning

confidence: 99%

Insights into Ionic Liquids: From Z-Bonds to Quasi-Liquids

Wang

et al. 2022

JACS Au

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Ionic liquids (ILs) hold great promise in the fields of green chemistry, environmental science, and sustainable technology due to their unique properties, such as a tailorable structure, the various types available, and their environmentally friendly features. On the basis of multiscale simulations and experimental characterizations, two unique features of ILs are as follows: (1) strong coupling interactions between the electrostatic forces and hydrogen bonds, namely in the Z-bond, and (2) the unique semiordered structure and properties of ultrathin films, specifically regarding the quasi-liquid. In accordance with the aforementioned theoretical findings, many cutting-edge applications have been proposed: for example, CO 2 capture and conversion, biomass conversion and utilization, and energy storage materials. Although substantial progress has been made recently in the field of ILs, considerable challenges remain in understanding the nature of and devising applications for ILs, especially in terms of e.g. in situ /real-time observation and highly precise multiscale simulations of the Z-bond and quasi-liquid. In this Perspective, we review recent developments and challenges for the IL research community and provide insights into the nature and function of ILs, which will facilitate future applications.

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“…The theory of excess absorption spectroscopy can be found in detail in the previous studies, ,,− and a summary of the theory is provided in the Supporting Information.…”

Section: Experimental Methodsmentioning

confidence: 99%

Is the Fourier Transform Infrared Free-OH Band of t-Butanol Only from Free OHs? Case Studies on the Binary Systems of the Alcohol with CCl₄ and CHCl₃

Kalhor

Zheng

2020

J. Phys. Chem. A

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Attenuated total reflection−Fourier transform infrared spectroscopy and quantum chemical calculations were performed on tert-butyl alcohol (t-BuOH) and its binary solutions with CCl 4 and CHCl 3 . The study was focused on the free-OH stretching bands. Two resolution-enhancing methods, excess spectroscopy and two-dimensional correlation spectroscopy, were employed to examine the structural heterogeneity and search for the detailed contributors to the free-OH bands. Unexpectedly, CCl 4 was found not to be an inert solvent and, similar to CHCl 3 , formed hydrogen/halogen bonds (H-/X-bond) with t-BuOH. It was observed that the free-OH band in the t-BuOH−CHCl 3 system is larger and more red-shifted than that in the t-BuOH− CCl 4 system, indicating the stronger intermolecular interactions in the former system. Furthermore, in the t-BuOH−CHCl 3 system, the H-bonds are stronger than the X-bonds, while in the t-BuOH− CCl 4 system, both interactions are similar in strength. To assign the free-OH bands, it was found that they are not only from the free OH of the t-BuOH monomer, but they are also contributed by the quasi-free OH with the oxygen bonded to H or Cl and even the weakly H-bonded OH of t-BuOH molecules. Finally, all the identified species increased simultaneously via cosolvent addition, suggestive of the destabilization of the highly associated t-BuOH clusters.

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Excess spectroscopy and its applications in the study of solution chemistry

Cited by 42 publications

References 97 publications

The Structures of ZnCl2-Ethanol Mixtures, a Spectroscopic and Quantum Chemical Calculation Study

The Structures of ZnCl2-Ethanol Mixtures, a Spectroscopic and Quantum Chemical Calculation Study

Insights into Ionic Liquids: From Z-Bonds to Quasi-Liquids

Is the Fourier Transform Infrared Free-OH Band of t-Butanol Only from Free OHs? Case Studies on the Binary Systems of the Alcohol with CCl₄ and CHCl₃

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Excess spectroscopy and its applications in the study of solution chemistry

Cited by 42 publications

References 97 publications

The Structures of ZnCl2-Ethanol Mixtures, a Spectroscopic and Quantum Chemical Calculation Study

The Structures of ZnCl2-Ethanol Mixtures, a Spectroscopic and Quantum Chemical Calculation Study

Insights into Ionic Liquids: From Z-Bonds to Quasi-Liquids

Is the Fourier Transform Infrared Free-OH Band of t-Butanol Only from Free OHs? Case Studies on the Binary Systems of the Alcohol with CCl4 and CHCl3

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Product

Resources

About

Is the Fourier Transform Infrared Free-OH Band of t-Butanol Only from Free OHs? Case Studies on the Binary Systems of the Alcohol with CCl₄ and CHCl₃