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

Cáceres, Mercedes; Lobato, Álvaro; Mendoza, Nubia Judith; Bonales, Laura J.; Baonza, Valentı́n G.

doi:10.1039/c6cp03857c

Cited by 8 publications

(3 citation statements)

References 26 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Since this increase in gauche conformers was found to be pressure-independent, we can conclude that water molecules do not play a significant role in the molecular arrangement of the alkane chains in the bulk. Similar studies on ethylenediamine 69 as well as on dimethoxyethane and dimethoxymethane 70 have shown an opposite effect. By applying Raman spectroscopy, both Caćeres et al 69 and Wada et al 70 revealed an increase of gauche conformers by increasing the water concentration.…”

Section: ■ Introductionmentioning

confidence: 57%

“…Similar studies on ethylenediamine 69 as well as on dimethoxyethane and dimethoxymethane 70 have shown an opposite effect. By applying Raman spectroscopy, both Caćeres et al 69 and Wada et al 70 revealed an increase of gauche conformers by increasing the water concentration. The absent influence of water molecules on the observed alkane−alkane contacts can be explained by the water spreading in the alkane-rich liquid phase during the solvation process combined with its low solubility, 30 which hinders the formation of hydrogen bonds.…”

Section: ■ Introductionmentioning

confidence: 57%

See 1 more Smart Citation

Characterization of Water Solubility in n-Octacosane Using Raman Spectroscopy

et al. 2017

View full text Add to dashboard Cite

In this study, we demonstrate the ability of polarization-difference Raman spectroscopy (PDRS) to detect dissolved free water molecules in a n-octacosane (n-CH) liquid-rich phase, and thus to determine its solubility, at temperatures and pressures relevant to the Fischer-Tropsch synthesis. Our results for the pure alkane reveal thermal decomposition above a temperature of 500 K as well as an increase of gauche conformers of the alkane chains with an increase in temperature. For binary homogeneous mixtures, raw spectra obtained from two different polarization scattering geometries did not show a relevant signal in the OH stretching frequency range. In contrast, isotropic spectra obtained from the PDRS technique reveal a narrow and tiny peak associated with the dangling OH bonds. Over the complete range of temperatures and pressures, no signature of hydrogen-bonded water molecules was observed in the isotropic Raman scattering intensities. A thorough investigation covering a large range of temperatures and pressures using PDRS signals showed that the higher the fraction of gauche conformers of hydrocarbon, the higher the solubility of water. The proportion of gauche and trans conformers was found to be water-concentration-independent, and the intensity of the OH-dangling peak increased linearly with increasing the vapor partial pressure of water. Therefore, we established a relation between a relevant intensity ratio and the concentration of water obtained from SAFT calculations. Contrary to the results from relevant literature, the calibration factor was found to be temperature-independent between 424 and 572 K. The isotropic Raman scattering intensities are corrected in order to provide a better representation of the vibrational density of states. The influence of correction of the isotropic scattering intensities on the solubility measurements as well as on the analysis of the molecular arrangement is discussed.

show abstract

Section: ■ Introductionmentioning

confidence: 57%

Section: ■ Introductionmentioning

confidence: 57%

Characterization of Water Solubility in n-Octacosane Using Raman Spectroscopy

et al. 2017

View full text Add to dashboard Cite

show abstract

“…[ 29 ] Furthermore, we previously demonstrated that the extent of these molecular interactions can be quantified in terms of local pressure by using Raman spectra of a given molecule at high pressure as a reference. [ 30,31 ]…”

Section: Resultsmentioning

confidence: 99%

Dehydration rate of the glycine‐MgSO₄·5H₂O complex and the stability of glycine expelled from the complex by in situ Raman spectroscopy under Mars‐relevant conditions

Bonales

Rodríguez-Villagra

Fernández-Sampedro

et al. 2022

J Raman Spectroscopy

Self Cite

View full text Add to dashboard Cite

In this work, we studied the dehydration process of the glycine‐MgSO4·5H2O complex under Mars‐relevant conditions (99% CO2 and 0.6% H2O under ultra violet (UV) irradiation exposure at 7‐mbar pressure and high vacuum conditions: 8 × 10−5 and 5 × 10−5 mbar) by in situ Raman spectroscopy inside a planetary atmosphere and surface chamber (PASC). This work provides quality Raman spectra taken under simulated planetary conditions (to be integrated in a database), as Raman spectroscopy forms part of the current and upcoming NASA and ESA Mars planetary missions. The results demonstrate that Raman spectroscopy can be used to calculate rates of dehydration of the glycine‐MgSO4·5H2O compound to study the chemical stability with respect to photodecomposition (1) of metal‐bound glycine molecules forming the complex and (2) glycine expelled from the complex, both under Mars‐simulated conditions; finally, Raman spectroscopy can also be used to quantify intermolecular interactions in terms of local pressures. Importantly, advanced detection of water molecules as part of a complex with astrobiological interest under planetary conditions plays a crucial role in planetary missions.

show abstract

One-step hydrothermal synthesis of flower-like CoS hierarchitectures for application in supercapacitors

Zhu

Lei

et al. 2018

Bull Mater Sci

View full text Add to dashboard Cite

Flower-like CoS hierarchitectures were successfully synthesized through a hydrothermal route in the presence of ethylenediamine as ligand and structure-directing agent. The structure and morphology of the products were characterized by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy and N 2 adsorptiondesorption isotherm. Flower-like CoS hierarchitectures are constructed by two-dimensional CoS nanopedals interlaced and stacked with each other. When tested as electrode material for supercapacitors, the as-fabricated CoS delivers a specific capacitance of 357 F g −1 at 0.5 A g −1. After 2000 repetitive charge-discharge cycles, there is only 12.7% loss of the original specific capacitance. The results signify that the CoS supercapacitor possesses good electrochemical performances, suggesting its potential application in supercapacitor.

show abstract

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

Cited by 8 publications

References 26 publications

Characterization of Water Solubility in n-Octacosane Using Raman Spectroscopy

Characterization of Water Solubility in n-Octacosane Using Raman Spectroscopy

Dehydration rate of the glycine‐MgSO₄·5H₂O complex and the stability of glycine expelled from the complex by in situ Raman spectroscopy under Mars‐relevant conditions

One-step hydrothermal synthesis of flower-like CoS hierarchitectures for application in supercapacitors

Contact Info

Product

Resources

About

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

Cited by 8 publications

References 26 publications

Characterization of Water Solubility in n-Octacosane Using Raman Spectroscopy

Characterization of Water Solubility in n-Octacosane Using Raman Spectroscopy

Dehydration rate of the glycine‐MgSO4·5H2O complex and the stability of glycine expelled from the complex by in situ Raman spectroscopy under Mars‐relevant conditions

One-step hydrothermal synthesis of flower-like CoS hierarchitectures for application in supercapacitors

Contact Info

Product

Resources

About

Dehydration rate of the glycine‐MgSO₄·5H₂O complex and the stability of glycine expelled from the complex by in situ Raman spectroscopy under Mars‐relevant conditions