scholarly journals N-H···O hydrogen bonding: An FT-IR, NIR study of N-methylformamide-ether systems

2010 ◽  
Vol 75 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Branislav Jovic ◽  
Aleksandar Nikolic ◽  
Erna Davidovic ◽  
Slobodan Petrovic
Keyword(s):  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Complex Formation ◽  
Diethyl Ether ◽  
Equilibrium Constants ◽  
Electron Donors ◽  
Butyl Ether ◽  
Dibutyl Ether ◽  
Spectroscopic Characteristics ◽  
Ft Ir

This paper reports the results of an FT-IR and NIR study of N-methylformamide in carbon tetrachloride solution in presence of ethers as the O-electron donors, i.e., diethyl ether (DEE), diisopropyl ether (DiPE), methyl t- -butyl ether (MtBE), dibutyl ether (DBE), dipentyl ether (DPE), tetrahydrofuran (THF) and tetrahydropyran (THP). The spectroscopic characteristics of the N-H???O hydrogen bonded complexes are given. In addition, the equilibrium constants for 1:1 complex formation were determined at 25?C using Mid-IR and NIR measurements.

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.

Hydrogen bonding of alcohols with AOT in carbon tetrachloride: an infrared study

1985 ◽  
Vol 63 (12) ◽  
pp. 3367-3370 ◽  
Author(s):  
Pierre Ménassa ◽  
Camille Sandorfy
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectroscopy ◽  
Carbon Tetrachloride ◽  
Equilibrium Constants ◽  
Short Chain ◽  
Infrared Study ◽  
Free Band ◽  
Long Chain ◽  
Cyclic Alcohols ◽  
Aliphatic Chains

The interaction of the inverted micelles of AOT (sodium di(2-ethylhexyl)sulfosuccinate) with different alcohols due to hydrogen bonding has been studied by means of infrared spectroscopy. Spectra of solutions of the alcohols with increasing concentrations of AOT showed a decrease in the intensity of the free OH stretching band. At the same time a new OH band due to a H-bonded alcohol-inverted micelle complex appears and its intensity increases as the intensity of the free band decreases. Calculated values of the equilibrium constants for the formation of the complexes n-alcohol–AOT, showed a decrease in alcohol–AOT association with the increase of the length of the aliphatic chains in the n-alcohols. Surprisingly, cholesterol behaved like a short chain while other cyclic alcohols like long chain alcohols.

scholarly journals The second virial coefficients of organic vapours

1949 ◽  
Vol 196 (1044) ◽  
pp. 113-125 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Diethyl Ether ◽  
Methyl Alcohol ◽  
Virial Coefficients ◽  
Dipole Interaction ◽  
Conductivity Data ◽  
Second Virial Coefficients ◽  
Critical Data

The compressibilities of a num ber of organic vapours have been measured at pressures up to 1 atm. and temperatures ranging from 40 to 130° C. The observed second virial coefficients are compared with values calculated from the critical data by the Berthelot equation. The results show two distinct classes of behaviour. Class I is shown by ethane, ethylene, n -hexane, cyclohexane, benzene, diethyl ether, ethyl chloride, chloroform and carbon tetrachloride, where the measured second virial coefficients are in agreement with the calculated values. Class II by acetaldehyde, acetone, acetonitrile, methyl alcohol, where the measured second virial coefficients are consistently very much higher than the calculated values. It is concluded that the vapours of polar substances for which the energy of attraction between molecules, due to dipole interaction or to hydrogen bonding, is larger than kT undergo dim erization. This view is supported by thermal conductivity data. The range of validity of the Berthelot equation for both non-polar and polar vapours is examined.

Association between halothane and oxygenated solvents by 1H NMR spectroscopy

1995 ◽  
Vol 73 (9) ◽  
pp. 1406-1411 ◽  
Author(s):  
Marcela Tkadlecová ◽  
Jaroslav Havlíček ◽  
Vladimír Dohnal
Keyword(s):  
Nmr Spectroscopy ◽  
Complex Formation ◽  
Equilibrium Constants ◽  
Solution Model ◽  
Methyl Tert Butyl Ether ◽  
Ideal Solution ◽  
Butyl Ether ◽  
Complex Formation Equilibria ◽  
H Nmr ◽  
Halothane Concentration

Using 1H NMR spectroscopy the complex-formation equilibria between halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) and methyl tert-butyl ether or tetrahydrofuran in various inert solvents (hexane, heptane, decane, cyclohexane) were measured as a function of temperature. For two different association models (ideal solution and athermal solution), assuming only the formation of a 1:1 H-bonded complex, the equilibrium constants and the standard enthalpies of the complex-formation reaction were calculated. The ideal solution model provides values of the equilibrium constant that differ for different inert solvents. The athermal solution model makes this false solvent effect much smaller. For the low halothane concentration used, its dimerization was neglected. This assumption was verified experimentally. Keywords: 1H NMR, association, complex formation, halothane.

The ionization energies of some phenothiazine tranquillizers and molecules of similar structure

1968 ◽  
Vol 21 (4) ◽  
pp. 873 ◽  
Author(s):  
A Fulton ◽  
LE Lyons
Keyword(s):  
Charge Transfer ◽  
Complex Formation ◽  
Molecular Orbital ◽  
Equilibrium Constants ◽  
Electron Donors ◽  
Molecular Orbital Calculations ◽  
Strong Electron ◽  
Ionization Energies ◽  
Physiological Action ◽  
The Difference

Charge-transfer spectroscopy was used to determine the ionization energies of ten phenothiazine tranquillizers and similar molecules which are stimulants, in order to throw light on the proposed relation between physiological action and electron-donating power, and to compare the ionization energies of the phenothiazines with molecular orbital calculations. All the ionization energies obtained lie in the range 7.0-8.4 eV. The phenothiazines are thus strong electron donors, in agreement with calculations. There is little difference in ionization energies and equilibrium constants of complex formation between tranquillizers and either non-tranquillizers or stimulants. The difference in physiological action of the drugs therefore cannot be dependent on electron-donating power alone.

Hydrogen bonding between phenols and cyanides

1966 ◽  
Vol 291 (1427) ◽  
pp. 460-468 ◽  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Carbon Tetrachloride ◽  
Equilibrium Constants ◽  
Lone Pair ◽  
Frequency Shifts ◽  
Tertiary Butyl ◽  
Group Frequency ◽  
Steric Factors ◽  
Lone Pair Electrons

The association between phenols and cyanides, dissolved in carbon tetrachloride, has been measured. The shifts of the bonded OH group frequency have been determined for a range of cyanides, and correlated with the Taft inductive factors of the groups concerned. Equilibrium constants for the formation of the complexes have been determined and correlated with the frequency shifts. The influence of steric factors has been studied, and it has been found that tertiary butyl groups in the ortho positions of phenol restrict the formation of the hydrogen bond. In most cases, the C≡N group frequency is displaced to higher frequency when bonded to a phenol. This effect is unusual, and suggests that the bonding occurs through the lone pair electrons on the nitrogen atom. Some data on the widths of the association bands have been given.

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