Infrared studies on rotational isomerism. I. Ethylene glycol

1967 ◽  
Vol 45 (4) ◽  
pp. 397-407 ◽  
Author(s):  
Paul Buckley ◽  
Paul A. Giguère
Keyword(s):  
Ethylene Glycol ◽  
Equilibrium Configuration ◽  
Calorimetric Data ◽  
Kcal Mole ◽  
Bending Vibrations ◽  
Barrier Heights ◽  
Fundamental Frequencies ◽  
Infrared Studies ◽  
Intramolecular Hydrogen ◽  
Liquid And Solid Phases

The problem of the equilibrium configuration of the ethylene glycol molecule was investigated by measuring the infrared spectra of the vapor (up to 125 °C), liquid, and solid phases between 100 and 3 700 cm−1. The two isotopic molecules (CD2OH)2 and (CH2OD)2 were likewise studied. Most of the fundamental frequencies could be observed and assigned. These assignments, as well as the phase and temperature behavior of the spectra, confirm that in all cases the molecules exist only as gauche isomers, which are more stable than the trans as a result of intramolecular hydrogen bonds. Because these bonds are far from linear, the OH stretching vibrations are little affected, but the bending vibrations are strongly shifted towards higher frequencies.Comparison of the calculated thermodynamic functions with the calorimetric data shows that restriction of all three internal rotations in the glycol molecule lowers the entropy by about 10 e.u. at normal temperature. From the observed torsional frequencies, the average barrier heights are estimated to be of the order of 10 kcal/mole for rotation about the C—C bond, and 3 to 4 kcal/mole for rotation about the C—O bonds, thereby indicating a fairly rigid structure.

Infrared studies on rotational isomerism. III. 2-Chloro- and 2-bromo-ethanol

1969 ◽  
Vol 47 (6) ◽  
pp. 901-910 ◽  
Author(s):  
Paul Buckley ◽  
Paul A. Giguère ◽  
Michel Schneider
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Rotational Isomerism ◽  
Apparent Discrepancy ◽  
Trans Isomers ◽  
Kcal Mole ◽  
Infrared Studies ◽  
Isotopic Molecule ◽  
Intramolecular Hydrogen ◽  
Unambiguous Assignment

The relative intensities of the C—X stretching bands of the gauche and trans isomers in the vapor were measured as a function of temperature up to 165 °C for 2-chloroethanol, and up to 130 °C for 2-bromoethanol. From these the enthalpy differences between the two isomers were found to be 1.20 and 1.45 ± 0.1 kcal mole−1 respectively for the two halogenated ethanols. Similar measurements on the O—H stretching bands gave values higher than the above by 0.45 kcal mole−1 for both compounds. This apparent discrepancy is interpreted as due to a second gauche isomer, the OH group of which is not engaged in intramolecular hydrogen bonding, and which is less stable than the trans isomer.A study of the isotopic molecule ClCH2—CH2OD has led to unambiguous assignment of the OH bending and torsional frequencies. The spectra of the solid show that 2-chloroethanol can exist in two different crystalline phases: a stable one consisting of gauche molecules only, and a metastable one containing both isomers.

Infrared Studies on Rotational Isomerism. VI. Normal-Coordinate Analysis of 2-Chloro-, 2-Bromo-, and 2-Cyanoethanol

1972 ◽  
Vol 50 (2) ◽  
pp. 152-161 ◽  
Author(s):  
Paul A. Giguère ◽  
Michel Schneider
Keyword(s):  
Rotational Isomerism ◽  
Normal Coordinate Analysis ◽  
Force Constants ◽  
Potential Energy Distribution ◽  
Normal Coordinate ◽  
Bending Vibrations ◽  
Fundamental Frequencies ◽  
Infrared Studies ◽  
Fortran Language ◽  
Bond Strengths

A normal-coordinate analysis of three substituted ethanol molecules X—CH2—CH2—OH (where X = Cl, Br, or CN) was carried out using the simple valence force field model, and a computer program of Schachtschneider translated into Fortran language by Brooks. The effect of internal hydrogen bonding was studied by adding one extra symmetry coordinate, H … X (two, H … C and H … N, in the case of 2-cyanoethanol). The corresponding force constants show a good correlation with the hydrogen bond strengths. Most of the other force constants maintain the same value in the gauche and the trans rotamers. In general the calculated fundamental frequencies agree closely with the observed ones. The potential energy distribution confirms the extensive coupling between certain vibrations; particularly the skeleton stretching and the CH2 twisting and rocking. Only the C—X stretching and the skeleton bending vibrations are strongly affected by rotational isomerism.

Infrared studies on rotational isomerism. II. 2-Fluoroethanol

1968 ◽  
Vol 46 (18) ◽  
pp. 2917-2923 ◽  
Author(s):  
Paul Buckley ◽  
Paul A. Giguère ◽  
Daijiro Yamamoto
Keyword(s):  
Intramolecular Hydrogen Bonding ◽  
Rotational Isomerism ◽  
Condensed Phases ◽  
Frequency Range ◽  
Trans Isomers ◽  
Kcal Mole ◽  
Solid States ◽  
Infrared Studies ◽  
Free Molecules ◽  
Intramolecular Hydrogen

The infrared spectra of CH2FCH2OH were measured in the vapor, liquid, and solid states from 4000 to 200 cm−1. The Raman spectrum of the liquid was also measured over the same frequency range. From the results it appears that the free molecules exist almost entirely in the gauche configuration, which is stabilized by intramolecular hydrogen bonding. Only in the vapor at temperatures above 60 to 70 °C is there any indication of weak bands due to trans isomers. In the condensed phases the molecules are associated through strong hydrogen bonds (3–4 kcal/mole).

Rayleigh wing and Fourier transform infrared studies of intermolecular and intramolecular hydrogen bonds in liquid ethylene glycol

1995 ◽  
Vol 84 (4) ◽  
pp. 645-652 ◽  
Author(s):  
V. Crupi ◽  
M.P. Jannelli ◽  
S. Magazu' ◽  
G. Maisano ◽  
D. Majolino ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Hydrogen Bonds ◽  
Ethylene Glycol ◽  
Fourier Transform Infrared ◽  
Intramolecular Hydrogen Bonds ◽  
Infrared Studies ◽  
Intramolecular Hydrogen

Infrared studies on rotational isomerism. IV. 2-Cyanoethanol

1969 ◽  
Vol 47 (24) ◽  
pp. 4685-4690 ◽  
Author(s):  
Michel Schneider ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Rotational Isomerism ◽  
The Other ◽  
Trans Isomers ◽  
Kcal Mole ◽  
Infrared Studies ◽  
Enthalpy Difference ◽  
Temperature Deposition ◽  
Intramolecular Hydrogen

From the infrared spectra of the vapor measured between 4000 and 200 cm−1, 2-cyanoethanol was found to exist as gauche and trans isomers in roughly equal proportions around 100 °C. The gauche form is the more stable of the two, as in 2-chloro- and 2-bromo-ethanol, but the enthalpy difference is less than half as large; at most 0.7 kcal mole−1. This indicates some weak (about 1 kcal mole−1) intramolecular hydrogen bonding between the OH group and the π electrons of the C≡N bond.In the solid, two distinct crystalline phases have been observed. Crystal II, consisting of gauche molecules only, is normally obtained; for instance by annealing the vitreous solid from low temperature deposition of the vapor. Crystal I, which contains the two isomers, may be obtained irreversibly from the melt of crystal II under controlled conditions.On the other hand there was no indication in the spectra of a cyclic tautomer as suggested recently.

Dynamic Step-Scan Two-Dimensional Fourier Transform Infrared Studies of Uniaxially Drawn Poly(Ethylene Terephthalate) Film

1996 ◽  
Vol 50 (3) ◽  
pp. 377-381 ◽  
Author(s):  
Masashi Sonoyama ◽  
Kunihiro Shoda ◽  
Gen Katagiri ◽  
Hideyuki Ishida
Keyword(s):  
Ethylene Glycol ◽  
Phenyl Ring ◽  
Ethylene Terephthalate ◽  
High Mobility ◽  
Two Dimensional ◽  
Poly Ethylene Terephthalate ◽  
Dynamic Spectra ◽  
Infrared Studies ◽  
Poly Ethylene ◽  
Mechanical Stretching

Dynamic infrared spectra of uniaxially drawn poly(ethylene terephthalate) (PET) under a sinusoidal strain were examined. A very intense dynamic band at 973 cm−1 assigned to the trans C-O stretching mode indicated stress-induced high mobility around the C-O bond in the ethylene glycol units. It was supposed that derivative-like skeletal bands observed in the dynamic spectra originated from the stress-induced frequency shift. Two-dimensional correlation analyses of the dynamic spectra were also carried out and revealed that the phenyl ring 18a band at 1018 cm−1 and the phenyl ring 19b band at 1410 cm−1 were composed of three and two independent components, respectively. The correlation peaks between the phenyl ring and CH2 vibrational modes showed that orientation of the methylene group in the ethylene glycol unit, induced by mechanical stretching, is faster than that of the phenyl ring in the terephthalate unit.

β-Amino ketoximes: a study of basicity, hydrogen bonding and isomerism

1977 ◽  
Vol 30 (7) ◽  
pp. 1467 ◽  
Author(s):  
HK Powell ◽  
JM Russell
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Calorimetric Data ◽  
Amino Groups ◽  
Or Groups ◽  
Inductive Effects ◽  
Methylene Groups ◽  
Secondary Amino ◽  
Intramolecular Hydrogen ◽  
Cis And Trans

The protonation reactions of the diamine dioxime 4,4,9,9-tetramethyl- 5,8-diazadodecane-2,11-dione dioxime and its O-methyl and bis-O-methyl ethers have been studied at 25�, I 0.10 M NaCl. The (substituted) oxime groups cause a marked reduction in the basicity of the secondary amino groups. log K (potentiometric) and ΔH (calorimetric) data are interpreted in terms of inductive effects of the oxime group and possible intramolecular hydrogen bonding, N+-H...N(OR)=, pKa for methoxy-amine, NH2OMe, has been determined (4.62�0.01, I 0.10 M NaCl, 25�). ������ P.m.r. spectra are assigned for β-amino ketoximes having α- methyl and α-methylene groups cis and trans to =N-OR groups. Infrared spectra are reported.

scholarly journals Charge-transfer and impulsive electronic-to-vibrational energy conversion in ferricyanide: ultrafast photoelectron and transient infrared studies

2017 ◽  
Vol 19 (26) ◽  
pp. 17052-17062 ◽  
Author(s):  
José Ojeda ◽  
Christopher A. Arrell ◽  
Luca Longetti ◽  
Majed Chergui ◽  
Jan Helbing
Keyword(s):  
Charge Transfer ◽  
Ethylene Glycol ◽  
Energy Conversion ◽  
Vibrational Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Vibrational Energy ◽  
Metal Charge ◽  
Infrared Studies ◽  
Metal Charge Transfer

The photophysics of ferricyanide in H2O, D2O and ethylene glycol was studied upon excitation of ligand-to-metal charge transfer (LMCT) transitions by combining ultrafast photoelectron spectroscopy (PES) of liquids and transient vibrational spectroscopy.

An FT-IR study on intramolecular hydrogen-bonding in ethylene glycol derivatives

1991 ◽  
Vol 245 (3-4) ◽  
pp. 183-194 ◽  
Author(s):  
F.A.J. Singelenberg ◽  
J.H. van der Maas ◽  
L.M.J. Kroon-Batenburg
Keyword(s):  
Hydrogen Bonding ◽  
Ethylene Glycol ◽  
Intramolecular Hydrogen Bonding ◽  
Ft Ir ◽  
Ethylene Glycol Derivatives ◽  
Ir Study ◽  
Intramolecular Hydrogen
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