SPECTROSCOPIC STUDIES OF ALCOHOLS: II. THE CONFORMATION OF 2-HALOETHANOLS IN CARBON TETRACHLORIDE SOLUTION

1964 ◽  
Vol 42 (2) ◽  
pp. 326-339 ◽  
Author(s):  
P. J. Krueger ◽  
H. D. Mettee
Keyword(s):  
Carbon Tetrachloride ◽  
Equilibrium Constants ◽  
Spectroscopic Studies ◽  
Kcal Mole ◽  
Band Shift ◽  
Carbon Tetrachloride Solution ◽  
Hydrogen Bond Interactions ◽  
Conformational Equilibria ◽  
Intramolecular Hydrogen ◽  
Conformational Free Energy

Of the five conformers predicted for 2-haloethanols, only two (halogen and OH trans and gauche) can be positively identified by high resolution infrared spectroscopy. From the temperature dependence of the relative intensities of the fundamental OH stretching bands of the trans and gauche forms of the compounds XCH2CH2OH2 where X = F, Cl, Br, and I, the gauche conformers are shown to be energetically favored in dilute carbon tetrachloride solution, with enthalpy differences between the two conformers of 2.07 ± 0.53, 1.20 ± 0.09, 1.25 ± 0.08, and 0.81 ± 0.09 kcal/mole respectively. Equilibrium constants and the conformational free energy and entropy differences are reported. Inter- and intra-molecular OH … X hydrogen-bond interactions are found to be similar in that the enthalpy increases in the order X = I < Br < Cl < F, and is linearly related to a decrease in the fundamental OH band shift, in contrast to the Badger–Bauer relationship. The molecular and thermodynamic factors governing conformational equilibria involving intramolecular hydrogen bonds are discussed.

Synthesis of Silicon Carbide Films from Partially Oxidized Polyvinylsilane by Carbon Tetrachloride Solution Casting

2002 ◽  
Vol 17 (1) ◽  
pp. 214-223 ◽  
Author(s):  
Masaki Narisawa ◽  
Takeshi Hasegawa ◽  
Kiyohito Okamura ◽  
Masayoshi Itoh ◽  
Thomas Apple ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Carbon Tetrachloride ◽  
Radical Polymerization ◽  
Air Flow ◽  
Spectroscopic Studies ◽  
Flow Time ◽  
Silica Layer ◽  
Solution Casting ◽  
Amorphous Films ◽  
Carbon Tetrachloride Solution

Polyvinylsilane (PVS), derived from vinylsilane by radical polymerization, was partially oxidized in hot carbon tetrachloride solution by flowing air. If the air flow time is adjusted, soft gel films can be formed in a Teflon dish by casting the PVS solution. After the PVS films were peeled from the substrates, they were pyrolyzed at various temperatures. Spectroscopic studies of the pyrolyzed films up to 1273 K suggested that carbosilane (Si–CH2–Si) structures are formed in the films at 473–673 K. The compositions of the amorphous films obtained at 1673 K were approximately SiC1.38O0.21 and SiC1.41O0.51, depending on the crosslinking conditions. The oxygen incorporated in the films was removed in the form of CO and SiO during further heating at 1673–1873 K. The compositions of the films were changed to approximately SiC1.25 and SiC1.26, respectively, at 2073 K. The films obtained at 1273 K did not show degradation during the oxidation at 1273–1673 K while a protective silica layer was formed on their surfaces.

Factor analysis as a complement to band resolution. V. Complexing of pentachlorophenol and acetone in carbon tetrachloride solution

1978 ◽  
Vol 56 (23) ◽  
pp. 2959-2965 ◽  
Author(s):  
J. Korppi-Tommola ◽  
H. F. Shurvell
Keyword(s):  
Factor Analysis ◽  
Carbon Tetrachloride ◽  
Complex Formation ◽  
Infrared Spectrum ◽  
Equilibrium Constants ◽  
Complex Model ◽  
Carbon Tetrachloride Solution ◽  
Linear Relationships

Complex formation between pentachlorophenol and acetone and acetone-d6 in carbon tetrachloride solution has been studied in both the hydroxyl and carbonyl stretching regions of the infrared spectrum. Factor analysis of the digitized spectra indicates three absorbing components for each set of solutions in the hydroxyl stretching region. Concentration studies revealed roughly linear relationships between the areas of the 'free' ν(OH) band and both of the resolved complex bands, suggesting that two different 1:1 complexes occur in CCl4 solution. In the ν(CO) region only one band due to complex formation was detected. Equilibrium constants for the isotopically different complexes at about 30 °C are reported. In the hydroxyl stretching region, band resolution was also carried out using four components which gave a better fit to the observed spectrum. A set of equilibrium constants were then obtained. However, considerable difficulties were met in the calculations and in the interpretation of these results, so that the three band, two complex model is preferred.

SPECTROSCOPIC STUDIES OF ALCOHOLS: VI. INTRAMOLECULAR HYDROGEN BONDS IN ETHANOLAMINE AND ITS O- AND N-METHYL DERIVATIVES

1965 ◽  
Vol 43 (11) ◽  
pp. 2970-2977 ◽  
Author(s):  
P. J. Krueger ◽  
H. D. Mettee
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Temperature Dependence ◽  
Spectroscopic Studies ◽  
Intramolecular Hydrogen Bonds ◽  
Distinct Band ◽  
Conformational Equilibria ◽  
Methyl Derivatives ◽  
Intramolecular Hydrogen

The competitive intramolecular [Formula: see text] hydrogen bonding in ethanolamine and N-methylethanolamine has been studied in dilute C2Cl4 solution by means of the temperature dependence of the fundamental OH and NH stretching bands. Of the three conformers identified for each of these compounds, the least stable shows a distinct band which is assigned to a "terminal" OH group involved in an intramolecular [Formula: see text] hydrogen bond. Enthalpy differences between conformers are reported and discussed, and compared with those found for the conformational equilibria in 2-methoxyethylamine and N,N-dimethyl-ethanolamine.

SPECTROSCOPIC STUDIES OF ALCOHOLS: V. INTRAMOLECULAR HYDROGEN BONDS IN 2-CYANOETHANOL AND IN SOME NITROALCOHOLS

1965 ◽  
Vol 43 (10) ◽  
pp. 2888-2895 ◽  
Author(s):  
P. J. Krueger ◽  
H. D. Mettee
Keyword(s):  
Hydrogen Bonds ◽  
Spectroscopic Studies ◽  
Enthalpy Change ◽  
Kcal Mole ◽  
Gauche Conformation ◽  
Trans Form ◽  
Trans Conformer ◽  
Enthalpy Difference ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bonded

The enthalpy difference between the trans and the intramolecularly hydrogen bonded gauche conformation of 2-cyanoethanol in dilute CCl4 solution is shown to be −0.14 ± 0.03 kcal/mole from the temperature dependence of the fundamental OH stretching bands. At higher concentrations cyclic dimers with double OH … O bonds form. The enthalpy change on dimerization is −6.1 ± 0.3 kcal/mole. A small percentage of dimers with acylic OH … O bonds are also present, but these are thermodynamically less stable than the cyclic dimers.Intramolecular hydrogen bonds are found between OH and NO2 groups in some 2-nitro-alcohols, leading to stabilization of the gauche form with respect to the trans form. For 2-nitroethanol the trans conformer is in equilibrium with two intramolecularly hydrogen bonded conformers (ΔH = −0.40 ± 0.10 and −0.71 ± 0.09 kcal/mole respectively). 2,2-Dinitro-propanol and 2-methyl-2-nitro-1,3-propanediol show complex νOH bands due to trans and intramolecularly hydrogen bonded gauche conformers. 2,2,2-Trinitroethanol has a relatively narrow symmetrical OH peak at temperatures up to 55 °C which is assigned to the exclusively populated intramolecularly hydrogen bonded conformation.

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.

The Photo‐Chlorination of Methyl Chloroformate in Carbon Tetrachloride Solution

1949 ◽  
Vol 17 (6) ◽  
pp. 566-573 ◽  
Author(s):  
T. L. Batke ◽  
L. M. Dorfman ◽  
D. J. LeRoy
Keyword(s):  
Carbon Tetrachloride ◽  
Carbon Tetrachloride Solution
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