Molecular Structure of Butanediol Isomers in Gas and Liquid States:  Combination of DFT Calculations and Infrared Spectroscopy Studies

Jesus, A. J. Lopes; Rosado, Mário T. S.; Leitão, M. Luísa P.; Redinha, J.S.

doi:10.1021/jp027123l

Cited by 53 publications

(22 citation statements)

References 29 publications

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“…13,14 The geometry of the fully optimized isolated BD-CO 2 pair ( Figure 6) exhibits a LA-LB interaction between CO 2 and the O a -D a hydroxyl group in good agreement with the IR spectra described above. The calculated binding energy of the complex is -3.25 kcal/mol.…”

Section: Analysis Of the Diols-co 2 Interactions From Ab Initio Calcusupporting

confidence: 76%

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO₂: A Theoretical and Spectroscopic Study

et al. 2007

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The role played by supercritical carbon dioxide used as a dispersant medium in the synthesis of polyurethane particles has been investigated. High-temperature-high-pressure in situ infrared spectroscopic measurements combined with ab initio calculations were performed to investigate the hydroxyl stretching vibrations of ethylene glycol (EG) and 1,4-butanediol (BD), two monomers commonly used in the field of step growth polymerization. Specific interactions between the diols and CO2 have been put in evidence. While the structural characteristics of EG and BD are very similar--both diols have a gauche conformation due to an internal H-bond between the two hydroxyl functions--they behave differently in the presence of dense CO2. In the case of EG, this internal H-bond is broken, allowing the diol and CO2 to form a complex through the conjunction of a Lewis acid-Lewis base (LA-LB) interaction and a new H-bond. When BD complexes to CO2, this internal H-bond remains and is even reinforced indirectly by the LA-LB interaction occurring between the two moieties. In both cases, such a complex formation induces a polarization of the hydroxyl groups and consequently an increase of their nucleophilicity.

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Section: Analysis Of the Diols-co 2 Interactions From Ab Initio Calcusupporting

confidence: 76%

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO₂: A Theoretical and Spectroscopic Study

et al. 2007

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“…This procedure was similar to that applied in a previous study on this compound. 9 However, the range of the sampled structures was extended in this work to cover the conformations of 1,2-BD with relative energies within ca. 15 kJ mol À1 above the global minimum.…”

Section: Methodsmentioning

confidence: 99%

Stepwise conformational cooling towards a single isomeric state in the four internal rotors system 1,2-butanediol

Reva

Jesus

Rosado

et al. 2006

Phys. Chem. Chem. Phys.

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The present work explores the possibilities of the matrix isolation technique in the structural characterisation of highly flexible molecules. To date, most studies of this type were carried out on molecules with three or less internal degrees of freedom and a few (less than 10) possible conformations. The molecule of 1,2-butanediol has four conformationally relevant three-fold rotational axes, which can result in 81 possible conformations. A detailed theoretical study, at the MP2 and DFT(B3LYP) levels of theory with the 6-311++G(d,p) basis set, revealed that more than 20 conformers of 1,2-butanediol have relative energies in a 0-10 kJ mol À1 range and contribute appreciably to the gas phase equilibrium at room temperature. This fact renders conformational studies of the system extremely difficult under normal conditions. However, the method of matrix isolation permits the reduction of the number of populated conformational states in the experiment at low temperature due to the effect known as conformational cooling: low energy barriers promote the relaxation of the higher energy local minima into more stable structures. As a result of massive conformational cooling occurring upon matrix deposition, only five conformers of 1,2-butanediol were retained in the samples at 10 K. These conformers were identified using a combination of FTIR spectroscopy and extensive theoretical calculations of vibrational spectra. Annealing of the matrices up to 50 K resulted in the extreme case of conformational cooling related with the depopulation of all conformers into the most stable unique structure. The observed transformations were rationalized in terms of barriers to intramolecular rotation.

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“…They are widely used as solvents, reagents or chemical intermediates in various industries [13,14]. Owing to the molecular flexibility of butanediols, they exhibit several conformational features [15]. Due to the presence of two -OH groups in the molecule, the dielectric properties of these compounds are strongly influenced through the dipoledipole intermolecular interactions and hydrogen bonding.…”

Section: Introductionmentioning

confidence: 99%

Temperature and concentration dependence of the relative permittivity of (1,3-butanediol+1-octanol or 1,4-dioxane) binary liquid mixtures

Gilani

Ansari

2013

The Journal of Chemical Thermodynamics

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Molecular Structure of Butanediol Isomers in Gas and Liquid States: Combination of DFT Calculations and Infrared Spectroscopy Studies

Cited by 53 publications

References 29 publications

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO₂: A Theoretical and Spectroscopic Study

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO₂: A Theoretical and Spectroscopic Study

Stepwise conformational cooling towards a single isomeric state in the four internal rotors system 1,2-butanediol

Temperature and concentration dependence of the relative permittivity of (1,3-butanediol+1-octanol or 1,4-dioxane) binary liquid mixtures

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Molecular Structure of Butanediol Isomers in Gas and Liquid States: Combination of DFT Calculations and Infrared Spectroscopy Studies

Cited by 53 publications

References 29 publications

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO2: A Theoretical and Spectroscopic Study

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO2: A Theoretical and Spectroscopic Study

Stepwise conformational cooling towards a single isomeric state in the four internal rotors system 1,2-butanediol

Temperature and concentration dependence of the relative permittivity of (1,3-butanediol+1-octanol or 1,4-dioxane) binary liquid mixtures

Contact Info

Product

Resources

About

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO₂: A Theoretical and Spectroscopic Study

On the Perturbation of the Intramolecular H-Bond in Diols by Supercritical CO₂: A Theoretical and Spectroscopic Study