scholarly journals On the positional and orientational order of water and methanol around indole: a study on the microscopic origin of solubility

2016 ◽  
Vol 18 (33) ◽  
pp. 23006-23016 ◽  
Author(s):  
Andres Henao ◽  
Andrew J. Johnston ◽  
Elvira Guàrdia ◽  
Sylvia E. McLain ◽  
Luis Carlos Pardo
Keyword(s):  
Excess Entropy ◽  
Pure Water ◽  
Orientational Order ◽  
Water Solutions ◽  
Π Interactions ◽  
Microscopic Origin ◽  
Entropically Driven

The increase in solubility for indole in methanol water solutions relative to pure water is a result methanol −OH–π interactions. In addition, excess entropy calculations suggest that this process is enthalpically rather than entropically driven.

Interactions of Glycerol, Diglycerol, and Water Studied Using Attenuated Total Reflection Infrared Spectroscopy

2020 ◽  
Vol 74 (7) ◽  
pp. 767-779 ◽  
Author(s):  
Akari Habuka ◽  
Takeshi Yamada ◽  
Satoru Nakashima
Keyword(s):  
Infrared Spectroscopy ◽  
Pure Water ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Outer Side ◽  
Water Molecules ◽  
Glycerol Water ◽  
Oh Groups ◽  
Water Solutions ◽  
Band Area

In order to examine the mixing properties of glycerol–water and diglycerol–water solutions, these solutions were measured using attenuated total reflection infrared spectroscopy. The absorbance spectra corrected for 1 µm thickness were subtracted by pure polyols for obtaining water spectra, and by pure water for polyol spectra. Both asymmetric and symmetric CH2 stretching vibration bands (around 2940, 2885 cm−1) shifted about 10 cm−1 to lower wavenumber side (redshifts) with increasing polyol concentrations, especially at higher concentrations. Redshifts of C–O–H rocking bands (around 1335 cm−1) with increasing polyol concentrations are slightly larger for diglycerol–water (10 > 6 cm−1) than glycerol–water solutions. C–O stretching bands of CHOH groups (1125 and 1112 cm−1) shift slightly but in opposite sides for glycerol and diglycerol at highest polyol concentrations (90–100 wt%). These shifts of CH2 stretching, COH rocking, and CO stretching of CHOH at higher polyol concentrations suggest interactions of outer CH2 with inner CHOH groups of surrounding polyols. The normalized band area changes with polyol concentrations could be fitted by quadratic polynomials possibly due to mixtures of different interactions between water–water, polyol–water, and polyol–polyol molecules. The OH stretching band for diglycerol 90 wt% shows three humps indicating at least three OH components: long, medium, and short H bond water molecules. Short H bond water molecules are the major component possibly between inner CHOH and outer side CH2OH groups, while the long H component might loosely bind to outer CH2OH groups.

Zwitterionic vs porphyrin free-base structures in 4-phenylsulfonic acid meso-substituted porphyrins

2005 ◽  
Vol 09 (12) ◽  
pp. 852-863 ◽  
Author(s):  
Carlos Escudero ◽  
Zoubir El-Hachemi ◽  
Joaquim Crusats ◽  
Josep M. Ribó
Keyword(s):  
Water Solution ◽  
Pure Water ◽  
Critical Micellar Concentration ◽  
Solid Matrix ◽  
Free Base ◽  
Acid Base ◽  
Water Solutions ◽  
Hydrophilic Surfaces ◽  
J Aggregates ◽  
First Time

The 5,10,15,20-tetrakis(4-sulfophenyl)porphyrin (TPPS4) and 5-phenyl-10,15,20-tris(4-sulfophenyl)porphyrin (TPPS3)] were obtained for the first time as the pure sulfonic acid derivatives and characterized for their constitutional structure in the solid state and in water solution. The zwitterionic species in water solutions, above a critical micellar concentration, are stabilized by side-to-side homoassociation to J-aggregates (B-band: 490 nm), but in solids they only give the J-aggregates when water is present in enough amount. Severe dried solids show a zwitterionic species, stabilized by side-to-side interactions, that probably corresponds to the dimer (B-band: 455 nm). The monomeric zwitterion (B-band: 434 nm) is detected in dilute water solutions and its acid/base properties (concentration pK a (1/2) ≈ 5.0) are not significantly different from those of the acidified solutions of their sodium sulfonate derivatives. However, pure water solutions of TPPS n , in contrast to those of their sodium salts, show important interactions with hydrophilic surfaces: e.g. TPPS4 adsorbs on fused quartz forming a monolayer of the free-base porphyrin together with its counter cations. Dilution of the title porphyrins in a solid matrix (e.g. KBr ) leads to a free-base porphyrin species with a red-shifted B-band (424 nm) that points to a side-to-side homoassociation, which is in contrast with the typical π-stacked aggregates of the corresponding alkaline metal sulfonato salts.

scholarly journals Reply to the ‘Comment on “On the positional and orientational order of water and methanol around indole: a study on the microscopic origin of solubility” Phys. Chem. Chem. Phys., 2018, 20, DOI: 10.1039/C7CP03698A’

2018 ◽  
Vol 20 (3) ◽  
pp. 2116-2119
Author(s):  
L. C. Pardo ◽  
S. E. McLain
Keyword(s):  
Molecular Interaction ◽  
Orientational Order ◽  
Interaction Effects ◽  
Chem Phys ◽  
Microscopic Origin ◽  
Phys Chem Chem Phys

In this work we show that a theory aiming to describe solubility must have into account both steric and molecular interaction effects.

What is the primary mover of water dynamics?

2015 ◽  
Vol 17 (23) ◽  
pp. 15428-15434 ◽  
Author(s):  
P. Ben Ishai ◽  
S. R. Tripathi ◽  
K. Kawase ◽  
A. Puzenko ◽  
Yu. Feldman
Keyword(s):  
Relaxation Process ◽  
Pure Water ◽  
Water Dynamics ◽  
Present Evidence ◽  
Excess Wing ◽  
Microscopic Origin ◽  
Main Relaxation

We present evidence that the microscopic origin of both the excess wing and the main relaxation process of pure water is the same.

THE DETERMINATION OF HEAVY WATER

1949 ◽  
Vol 27b (1) ◽  
pp. 1-5 ◽  
Author(s):  
I. E. Puddington
Keyword(s):  
Heavy Water ◽  
Simple Procedure ◽  
Pure Water ◽  
Vapor Pressures ◽  
Water Solutions

A reasonably simple procedure for determining the concentration of heavy water solutions, based on the comparison of the vapor pressures of these solutions with pure water, has been developed. The method is useful for samples as small as 0.5 mgm. and the sample may be recovered. Individual determinations require about two hours. In the work reported, mean determinations did not vary from the best curve through the experimental points by more than 0.2 mole % of D2O, while the spread in any group of readings was about ±0.25 mole %.

Transmittance of Distilled Water and Sodium-Chloride-Water Solutions

1988 ◽  
Vol 110 (2) ◽  
pp. 113-119 ◽  
Author(s):  
K. Kanayama ◽  
H. Baba
Keyword(s):  
Absorption Coefficient ◽  
Water Surface ◽  
Pure Water ◽  
Specimen Thickness ◽  
Wavelength Band ◽  
Spectral Transmittance ◽  
Effective Absorption Coefficient ◽  
Water Solutions ◽  
Solar Pond ◽  
Effective Absorption

The spectral transmittance of pure water and salt water solutions of various concentrations, which are important for the thermal calculation of a solar pond, is measured experimentally for specimen thickness of 1 to 100 mm by means of an autorecording spectro-radiometer inside an air-conditioned room. On the basis of the measured spectral transmittance, the total transmittance of pure and salty waters to 3 m of water depth is calculated as a ratio of the total radiation energy over all wavelengths arriving at any depth from the water surface of the solar pond to the solar radiation incident upon the water surface with various air masses. According to Nielsens’ four-partition method, the effective absorption coefficient is calculated for each wavelength band. Lastly, the transmission properties obtained for pure water, i.e., spectral and total transmittances, absorption wavelength band, and effective absorption coefficient, are compared with past results, and those for salty water with various concentrations are compiled as basic data for the use of solar energy by a solar pond.

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