Hydrogen bonding in methanol—organic solvent and methanol—water mixtures as studied by the vco and voh

Bands, Raman; Käbisch, G.; Pollmer, K.

doi:10.1016/0022-2860(82)80077-x

Cited by 47 publications

(4 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, as it was expected, hydration effects in the COH group of methanol are opposite to those found in the methyl group, as confirmed in Figure , where the Raman shifts of the CO-stretch show a marked decrease as x H 2 O increases, confirming previous observations. ,,, Interestingly, we again distinguish three different behaviors on this band in concentration ranges almost coincidental with those found in Figure . Again, for the water-rich and methanol-rich regions the shift is less pronounced than in the intermediate region, but now a strong red-shift in the frequency is found, which must be interpreted as a weakening in the CO bond (i.e., bond-length increase) with increasing x H 2 O , in clear contrast to the behavior found for the methyl group.…”

Section: Resultssupporting

confidence: 91%

“…These studies confirm the long-known advantages of using vibrational spectroscopy to probe intermolecular interactions and structural information in water and methanol solutions. − The changes observed in the frequency, ν, of a given stretching vibration are directly related to the strengthening/weakening of those bonds involved in the intermolecular interactions in water solution. This strengthening or weakening of the bond can be quantified in terms of local pressures if high-pressure spectroscopy experiments are available for the pure liquids.…”

Section: Introductionsupporting

confidence: 73%

See 1 more Smart Citation

Local Hydration Pressures in Methanol Aqueous Solution: A Raman Spectroscopy Analysis

et al. 2014

View full text Add to dashboard Cite

Raman spectra of methanol-water mixtures were measured over the whole composition range at room conditions. The spectra are used to quantify the strength of intermolecular interactions in terms of local internal pressures. The conclusions derived from the spectroscopic analysis are discussed within the framework of the solvation pressure model using values of the cohesion energy density expected in the mixture. This work demonstrates that an appropriate analysis of Raman spectroscopy experiments can be used to quantify the local internal pressures due to intermolecular interactions in liquid mixtures, provided that high pressure results of the pure liquids are available.

show abstract

Section: Resultssupporting

confidence: 91%

Section: Introductionsupporting

confidence: 73%

Local Hydration Pressures in Methanol Aqueous Solution: A Raman Spectroscopy Analysis

et al. 2014

View full text Add to dashboard Cite

show abstract

“…It was observed that illumination perturbation affects the hydrogen bonds in water and since methanol also forms hydrogen bonds, it is likely that this phenomenon will also affect the methanol spectra. 27 Therefore, equation (2) was used to determine the effect of illumination perturbation on the methanol spectra by subtracting the mean methanol spectrum from the mean methanol spectra of each of the instrumental repeats.Where:mk_diff = methanol difference spectra for instrumental repeat k truem¯k = mean methanol spectrum for instrumental repeat km¯ = mean methanol spectrum…”

Section: Methodsmentioning

confidence: 99%

Determination of potential absorbance bands of fumonisin B1 in methanol with near infrared spectroscopy

Laubscher,

Rose,

Williams

2023

Journal of Near Infrared Spectroscopy

View full text Add to dashboard Cite

The contamination of maize, a major staple food in South Africa, with fumonisin B1 (FB1), has become a major food safety concern. The regulation of this mycotoxin is extremely important and requires efficient detection methods. Near infrared (NIR) spectroscopy has gained widespread interest as a rapid and non-destructive mycotoxin analysis method. The purpose of this study was, therefore, to determine the NIR absorbance bands of FB1. The spectra of 30 FB1 solutions, constituted in methanol, as well as 30 methanol-only samples were recorded in the spectral range of 1000–2500 nm (10,000 – 4000 cm−1). The data was pre-processed with multiplicative scatter correction (MSC) and a partial least squares discriminant analysis (PLS-DA) model was computed. The variable importance in projection (VIP) scores and selectivity ratio (SR) values were used for wavelength selection. A new PLS-DA model was computed with 454 chosen wavelengths and the regression vector of this model was investigated to further identify and remove irrelevant wavelengths. The final model was computed with 150 wavelengths and nine latent variables (LVs) and obtained a classification accuracy of 100% for both the calibration and external validation sets. By investigating the regression vector of the final PLS-DA model, potential FB1 absorbance bands were identified at 1446 nm, 1453 nm, 1891 nm, 2036 nm, 2046 nm, 2148 nm, 2224 nm, 2262 nm and 2273 nm. This study was therefore able to identify the previously unknown NIR absorbance bands of FB1 at 100 ppm.

show abstract

“…In order to shed some light on the above issues, here we use Raman spectroscopy to monitor the conformational changes of EDA in aqueous solutions across the whole composition range, due to the suitability of this spectroscopy for probing inter/ intramolecular interactions and structural changes in the liquid phase. [12][13][14][15][16][17][18] We base our analysis on the assumption that there exists a balance between inter-and intra-molecular hydrogen bonding in EDA resulting from variations in the molecular environment. Since changes in the frequency (n) of a stretching vibration can be related to a strengthening/weakening of the bonds involved in such a vibrational mode, we have also attempted to quantify the extent of such molecular interactions in terms of local pressures.…”

Section: Measured Thementioning

confidence: 99%

Local, solvation pressures and conformational changes in ethylenediamine aqueous solutions probed using Raman spectroscopy

Cáceres

Lobato

Mendoza

et al. 2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

Raman spectra of 1,2-ethylenediamine (EDA) in aqueous solutions are used to demonstrate that EDA molecules experience an anti-gauche conformational change resulting from the interactions with water. The observed Raman shift reveals a compressive (hydrophobic) effect of water on both methylene and amino groups of EDA. Raman spectra of EDA at high pressures are used as reference to quantify the intermolecular EDA-HO interactions in terms of local pressures. These results are compared with macroscopic solvation pressures calculated from the cohesive energy parameter. We compare and discuss all our observations with available computational and experimental studies.

show abstract

Hydrogen bonding in methanol—organic solvent and methanol—water mixtures as studied by the vco and voh

Cited by 47 publications

References 18 publications

Local Hydration Pressures in Methanol Aqueous Solution: A Raman Spectroscopy Analysis

Local Hydration Pressures in Methanol Aqueous Solution: A Raman Spectroscopy Analysis

Determination of potential absorbance bands of fumonisin B1 in methanol with near infrared spectroscopy

Local, solvation pressures and conformational changes in ethylenediamine aqueous solutions probed using Raman spectroscopy

Contact Info

Product

Resources

About