Differentiation of ethanol-water clusters in Fenjiu by two-dimensional correlation fluorescence and Raman spectra

Abstract Low-frequency Raman spectra have been measured at room temperature as functions of the alcohol mole fraction in aqueous solutions of methanol, ethanol, 1-propanol, 2 -propanol, and /er/-butylalcohol (TBA). Intrinsic Raman spectra R (ῡ) were obtained from depolarized Rayleigh wing spectra. Isosbestic points have been observed in R (ῡ) of the aqueous solutions of ethanol, 1-propanol, and 2 -propanol, suggesting that the structure o f the solutions is characterized by individual alcohol aggregates and water clusters without a significant amount of alcohol-water mixed aggregates. The R (ῡ) spectra have been expressed as R (ῡ ,x ) = w R (ῡ ,0 ) + aR(D, 1), where R(ῡ, 0) and R(ῡ, 1) are those for pure water and pure alcohols, respectively, and x is the mole fraction of alcohols. The coefficients w and a show the inflection points at characteristic alcohol mole fractions, where microhetrogeneity and structural transition of the solvent clusters take place, as previously shown by X-ray diffraction. In the aqueous solutions of methanol, where no microhetrogeneity takes place, no clear isosbestic point in R(ῡ) has been observed. For aqueous solutions of TBA, an isosbestic point in R(ῡ) has appeared when xTBA > 0.05. Two inflections points in the coefficients have been observed at xTBA « 0.1 and 0.35; the former composition corresponds to the transition composition from the TBA-TBA intermolecular contact to the TBA water molecular association, as previously reported by neutron diffraction.

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Water-Soluble Squaramide Dihydrates: N-Methylation Modulates the Occurrence of One- and Two-Dimensional Water Clusters through Hydrogen Bonding and Dipolar Interactions

Crystal Growth & Design ◽

10.1021/acs.cgd.8b00401 ◽

2018 ◽

Vol 18 (8) ◽

pp. 4420-4427 ◽

Cited By ~ 3

Author(s):

Marta Ximenis ◽

Javier Pitarch-Jarque ◽

Salvador Blasco ◽

Carmen Rotger ◽

Enrique García-España ◽

...

Keyword(s):

Hydrogen Bonding ◽

Water Clusters ◽

Water Soluble ◽

Two Dimensional ◽

Dipolar Interactions

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A two-dimensional hydrogen-bonded water layer in the structure of a cobalt(III) cubane complex

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229614001107 ◽

2014 ◽

Vol 70 (2) ◽

pp. 198-201 ◽

Cited By ~ 1

Author(s):

Ji Qi ◽

Xiang-Sheng Zhai ◽

Hong-Lin Zhu ◽

Jian-Li Lin

Keyword(s):

Water Clusters ◽

Three Dimensional ◽

Water Layer ◽

Water Molecules ◽

Supramolecular Network ◽

Two Dimensional ◽

Solvent Water ◽

Water Layers ◽

Hydrogen Bonded

A tetranuclear CoIIIoxide complex with cubane topology, tetrakis(2,2′-bipyridine-κ2N,N′)di-μ2-carbonato-κ4O:O′-tetra-μ3-oxido-tetracobalt(III) pentadecahydrate, [Co4(CO3)2O4(C10H8N2)4]·15H2O, with an unbounded hydrogen-bonded water layer, has been synthesized by reaction of CoCO3and 2,2′-bipyridine. The solvent water molecules form a hydrogen-bonded net with tetrameric and pentameric water clusters as subunits. The Co4O4cubane-like cores are sandwiched between the water layers, which are further stacked into a three-dimensional metallo-supramolecular network.

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