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Hu K, Zhou Y, Shen J, Ji Z, Cheng G. Microheterogeneous Structure of 1-Octanol in Neat and Water-Saturated State. J Phys Chem B 2007; 111:10160-5. [PMID: 17683135 DOI: 10.1021/jp072847o] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conformational and dynamic properties of 1-octanol in neat and in water-saturated states have been investigated by 1H NMR. It has been proved that neat 1-octanol is microheterogeneous in nature comprising regions enriched in either hydrocarbons or hydroxyl groups. A reversed micelle-like cluster model was proposed, where the octanol cluster has an inner polar core of hydrogen-bonded octanol hydroxyls and an outer shell of nonpolar alkyl chains radiating outside. It was also observed that the cluster structure of octanol experiences minor changes with the presence of water. In water-saturated octanol, water molecules associate via hydrogen bonding and reside in the innermost center of the polar region with restricted motion, whereas the octanol cluster structure is modified by loosening the compact structure. Moreover, the preferential solvations of both systems were tested and compared. It not only gives some clues about the microheterogeneity of the alcohol system and the structure of the cluster but also helps in advancing our understanding on the behavior and properties of the amphiphilic molecules system such as phospholipids.
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Affiliation(s)
- Kai Hu
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, China
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Cataliotti RS, Palombo F, Paolantoni M, Sassi P, Raudino A. Concentration fluctuations and collective properties in mixed liquid systems: Rayleigh-Brillouin spectra oftert-butyl alcohol/ 2,2′-dimethylbutane liquid mixture. J Chem Phys 2007; 126:044505. [PMID: 17286485 DOI: 10.1063/1.2431170] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rayleigh-Brillouin spectra have been measured in a range of temperatures and compositions of t-butyl alcohol/2,2(')-dimethylbutane liquid mixture. The mixture mole fraction has been varied from pure alkane (x(TBA)=0) to pure alcohol (x(TBA)=1) at temperatures between 283 and 323 K. In the same composition and temperature ranges the authors also executed measurements of mass density, shear viscosity, and refractive index. From light scattering spectra the authors have extracted the hypersound velocities and adiabatic compressibilities and evaluated their excess values. Moreover, the authors attempted to evaluate the isothermal (40 degrees C) Landau-Placzek ratios at various mole fractions, but these values proved to be subject to significant errors due to great uncertainty in the central component intensity measurements. Thus, in discussing the results, this latter quantity was considered only from a qualitative point of view. These results highlight a nonideal behavior of the studied liquid mixture with a probable azeotropic composition around x(TBA)=0.7 due to formation of small clusters of hydrogen-bonded alcohol tetramers that are completely surrounded by solvent molecules and analogous or smaller clusters. These clusters, shaped as inverse micelles, offer their hydrophobic moiety towards the molecules that constitute the solvation shell, resulting in a low polarity solution structure that minimizes the solute-solvent interactions. Differences in thermal and compositional behavior of excess molar volumes and adiabatic compressibilities have been interpreted by attributing different weights to the solute-solvent interaction forces and to the hydrogen bond connectivity effects.
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Affiliation(s)
- Rosario Sergio Cataliotti
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto 8, I-06001 Perugia, Italy.
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Gallina ME, Sassi P, Paolantoni M, Morresi A, Cataliotti RS. Vibrational Analysis of Molecular Interactions in Aqueous Glucose Solutions. Temperature and Concentration Effects. J Phys Chem B 2006; 110:8856-64. [PMID: 16640445 DOI: 10.1021/jp056213y] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A vibrational analysis using FTIR and Raman spectroscopies was carried out on aqueous glucose solutions with a wide range of solute molar fractions and temperatures. The analysis was aimed at revealing structural changes in the local hydrogen-bonding (HB) network of liquid water, correlating these with the conservative properties of biomolecules, and comparing them with those of other sugars. The results of our measurements clearly show that the action of glucose is 2-fold; on one hand, there is a linkage with free hydroxyls of water; on the other, there is a slight lessening of the ordered (tetrahedral) H-bonded assembly of bulk H(2)O. These opposite effects do not balance each other, so the average HB interaction strength decreases on increasing glucose concentration. As a result, there is a reduction in the temperature dependence of solutions structure. In our opinion, this could be related to the low bioprotective action of this carbohydrate.
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Affiliation(s)
- Maria Elena Gallina
- Dipartimento di Chimica, Università di Perugia, Via Elce di Sott, 8, 06100 Perugia, Italy
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Sassi P, Raudino A, Cataliotti RS. Isotope effects on the hydrodynamic fluctuations of self-associating fluids. A comparison between the Brillouin scattering of 1-octanol and its hydrocarbon chain perdeuterated analogue. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2005.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sassi P, Paolantoni M, Cataliotti RS, Palombo F, Morresi A. Water/Alcohol Mixtures: A Spectroscopic Study of the Water-Saturated 1-Octanol Solution. J Phys Chem B 2004. [DOI: 10.1021/jp046647d] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paola Sassi
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Marco Paolantoni
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Rosario Sergio Cataliotti
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Francesca Palombo
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Assunta Morresi
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto 8, I-06123 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
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Sassi P, Marcelli A, Paolantoni M, Morresi A, Cataliotti RS. Structural Properties of 1-Octanol/n-Octane Mixtures Studied by Brillouin Scattering. J Phys Chem A 2003. [DOI: 10.1021/jp0276606] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Paola Sassi
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto, 8, I-06100 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Agnese Marcelli
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto, 8, I-06100 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Marco Paolantoni
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto, 8, I-06100 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Assunta Morresi
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto, 8, I-06100 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
| | - Rosario Sergio Cataliotti
- Dipartimento di Chimica, Sezione di Chimica Fisica, Università di Perugia, Via Elce di Sotto, 8, I-06100 Perugia, Italy, and Istituto Nazionale di Fisica della Materia, Unità di Catania, 95100 Catania, Italy
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