Solvent effects on the infrared spectra of anilines. IV. Secondary aromatic amines and amides with trifluoromethyl or phenyl as ortho substituents

1967 ◽  
Vol 20 (1) ◽  
pp. 93 ◽  
Author(s):  
LK Dyall
Keyword(s):  
Hydrogen Bonding ◽  
Infrared Spectra ◽  
Aromatic Amines ◽  
Secondary Amines ◽  
Substituted Anilines ◽  
Frequency Shifts ◽  
Solvent Shift ◽  
Bonding Properties ◽  
Solvent Shifts ◽  
Ortho Substituent

The N-H stretching frequencies of five N-substituted anilines with trifluoro- methyl or phenyl as ortho substituent have been measured in a variety of solvents. Elevation of v(NH) by steric compression is observed. The frequency shifts observed for N-methyl-2-phenylaniline fit none of the three classes of solvent shift behaviour recognized for other ortho-substituted secondary amines. The results confirm that solvent shifts of v(NH) cannot be used to distinguish between the steric and hydrogen bonding properties of the ortho substituent.

Aromatic amides. V. Intramolecular hydrogen bonding in ortho-substituted anilides

1970 ◽  
Vol 23 (8) ◽  
pp. 1667 ◽  
Author(s):  
JM Appleton ◽  
BD Andrews ◽  
ID Rae ◽  
BE Reichert
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Geometry ◽  
Intramolecular Hydrogen Bonding ◽  
Amide Group ◽  
Amide Proton ◽  
Substituted Anilines ◽  
Real Value ◽  
Intramolecular Hydrogen ◽  
Acyl Derivatives ◽  
Ortho Substituent

The proton magnetic resonance spectra of deuterochloroform solutions of a number of ortho-substituted anilines and their S-acyl derivatives have been measured. Variations in the acylation shifts of the ring protons are explained in terms of intramolecular hydrogen bonding between the amide proton and the ortho-substituent. Calculations of the contribution made to the acylation shifts by the anisotropy of the amide group were found to be too sensitive to the molecular geometry to be of any real value. Acylation shifts for a series of 4'-substituted 2'-nitroacetanilides correlate well with the σp values of the 4'-substituents.

DOUBLE-MINIMUM POTENTIAL FOR INTRAMOLECULARLY HYDROGEN-BONDED PROTONS IN ORTHO-SUBSTITUTED ANILINES

1964 ◽  
Vol 42 (2) ◽  
pp. 201-211 ◽  
Author(s):  
P. J. Krueger
Keyword(s):  
Hydrogen Bonding ◽  
Vibrational Level ◽  
Fundamental Mode ◽  
Intramolecular Hydrogen Bonding ◽  
Antisymmetric Mode ◽  
Substituted Anilines ◽  
Minimum Potential ◽  
Intramolecular Hydrogen ◽  
Ortho Substituent ◽  
Hydrogen Bonded

The concentration and temperature-independent splitting of the first overtone NH2 symmetric stretching band in 31 ortho-substituted anilines in which intramolecular hydrogen bonding is possible is interpreted in terms of a double-minimum potential for the hydrogen bonded proton. The intensity ratio of the doublet and the extent of the splitting is related to the basicity of the ortho-substituent, modified by the rigid geometrical restrictions of the intramolecular system. The absence of band splitting in the corresponding fundamental mode suggests that the secondary minimum lies in the vicinity of the v = 2 vibrational level. The antisymmetric mode appears to be less sensitive to perturbations.Deuteration studies, the spectra of some o-substituted N-methyl anilines, and the first over-tone bands of N-methyl aniline in very basic solvents support these views.

Hydrogen Bonding in Organic Compounds. VI. Interaction between Groups in ortho-Substituted Anilines

1962 ◽  
Vol 15 (4) ◽  
pp. 626 ◽  
Author(s):  
AN Hambly ◽  
BV O'Grady
Keyword(s):  
Hydrogen Bonding ◽  
Small Difference ◽  
Amine Group ◽  
Substituted Anilines ◽  
Methyl Group ◽  
Rotational Isomers ◽  
No Formation ◽  
Weak Hydrogen Bonds ◽  
Alkoxy Groups ◽  
Ortho Substituent

The infrared spectra of anilines, with a single methyl group as ortho-substituent, conform to the modified Bellamy and Williams equation which was found to correlate the antisymmetric and symmetric stretching frequencies of the NH2 group when only meta- or para-substituents were present. Methyl substituents at both positions 2 and 6 to the amine produce a change that can be described as anti-hydrogen bonding. Substitution by alkoxy groups or halogen at the position ortho to the amine group causes deviations from the equation in the direction indicative of hydrogen bonding. Monodeuterated 2-bromo-, 2-iodo, and 2-cyanoaniline give evidence of extremely weak hydrogen bonds by a small difference in the NH and ND vibrations of two isomeric forms bonded through H and D respectively. The spectra of monodeuterated 2-alkoxy-, 2-fluoro-, and 2-phenylaniline did not show any resolution of the bands due to NH and ND vibrations, and hydrogen bonding between the ortho-substituents can be regarded as negligible in these compounds. An o-trifluoromethyl substituent appears to exert a repulsive effect on the amine group with no formation of a hydrogen bond. Rotational isomers occur in carbon tetrachloride solutions of 2,6-dihalogeno-4-nitroanilines.

A SPECTROSCOPIC STUDY OF HYDROGEN BONDING IN PERFORMIC AND PERACETIC ACIDS

1952 ◽  
Vol 30 (11) ◽  
pp. 821-830 ◽  
Author(s):  
Paul A. Giguère ◽  
A. Weingartshofer Olmos
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Peracetic Acid ◽  
The Other ◽  
Frequency Shifts ◽  
Vapor State ◽  
Nonpolar Solvents ◽  
Intramolecular Hydrogen

The infrared spectra of concentrated performic and peracetic acids were measured in the rock-salt region. The most significant features are theO—H stretching frequency at 3310–3350 cm−1 and the OH bending frequency at 1450 cm−1 which, for both peracids, remain essentially the same in the vapor state as in the liquid or in solution in nonpolar solvents. This is attributed to intramolecular hydrogen bonds resulting in particularly stable five-membered rings,[Formula: see text]Steric conditions in the percarboxylic group are favourable to such ring formation or chelation. From the observed frequency shifts the energy of these hydrogen bonds is estimated to be about 7 kcal. per mole. No evidence for unchelated molecules was found even in very dilute solutions of peracetic acid in nonpolar solvent nor in the vapour at low pressure and moderate temperature. Tentative assignments of the other frequencies in the spectra of the peracids are made by comparison with those of formic and acetic acids.The danger involved in handling these peracids in concentrated form is emphasized.

Hydrogen-bonded complexes of perfluoro-t-butanol with acetone and nitromethane in low temperature solutions and matrices

1991 ◽  
Vol 69 (10) ◽  
pp. 1520-1527 ◽  
Author(s):  
Louise Schriver ◽  
André Schriver ◽  
Stefan Peil ◽  
Otto Schrems
Keyword(s):  
Hydrogen Bonding ◽  
Low Temperature ◽  
Key Words ◽  
Infrared Spectra ◽  
Temperature Effects ◽  
Bonding Temperature ◽  
Proton Donor ◽  
Frequency Shifts ◽  
Binary Complexes ◽  
Solid Matrices

Infrared spectra are reported for binary complexes between perfluoro-tert-butanol as proton donor and nitromethane and acetone as bases. The complexes have been investigated in low temperature solutions and in cryogenic matrices. The spectra have been evaluated in terms of frequency shifts (ΔVOH), half widths (FWHH) and anharmonicities (κ) caused by the hydrogen bonding of these complexes. The influence of the environment (solvents and solid matrices) as well as temperature on the spectra of the complexes has also been studied and is discussed in detail. Key words: hydrogen bonding, temperature effects, solutions, matrix.

Analysis of Aromatic Amines in Industrial Wastewater by Capillary Gas Chromatography-Mass Spectrometry

2000 ◽  
Vol 35 (2) ◽  
pp. 245-262 ◽  
Author(s):  
Francis I. Onuska ◽  
Ken A. Terry ◽  
R. James Maguire
Keyword(s):  
Gas Chromatography ◽  
Aromatic Amines ◽  
Methylene Chloride ◽  
Solid Phase ◽  
Stationary Phases ◽  
Gas Chromatography Mass Spectrometry ◽  
Substituted Anilines ◽  
Environmental Media ◽  
Solid Phase Extraction Cartridge ◽  
Wide Range

Abstract The analysis of aromatic amines, particularly benzidines, at trace levels in environmental media has been difficult because of the lack of suitable deactivated capillary column stationary phases for gas chromatography. This report describes the use of an improved type of column as well as a method for the analysis of anilines and benzidines in water, wastewater and sewage samples. Extraction procedures are applicable to a wide range of compounds that are effectively partitioned from an aqueous matrix into methylene chloride, or onto a solid-phase extraction cartridge. The extracted analytes are also amenable to separation on a capillary gas chromatographic column and transferable to the mass spectrometer. These contaminants are converted to their N-trifluoroacetyl derivatives. Aniline and some substituted anilines, and 3,3’-dichlorobenzidine and benzidine were determined in 24-h composite industrial water, wastewater, primary sludge and final effluent samples at concentrations from 0.03 up to 2760 µg/L.

The hydrogen-bonding properties of a room temperature phosphorescence cellulose substrate

1986 ◽  
Vol 90 (21) ◽  
pp. 4941-4945 ◽  
Author(s):  
Georg W. Suter ◽  
Alan J. Kallir ◽  
Urs P. Wild ◽  
Tuan Vo-Dinh
Keyword(s):  
Hydrogen Bonding ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Cellulose Substrate ◽  
Bonding Properties
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