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.

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.

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.

Chlorido(dimethyl 2,2′-bipyridine-4,4′-dicarboxylate-κ2N,N′)(η5-pentamethylcyclopentadienyl)rhodium(III) chloride 1-hydroxypyrrolidine-2,5-dione disolvate

2013 ◽  
Vol 69 (6) ◽  
pp. 584-587
Author(s):  
Dharmalingam Sivanesan ◽  
Hyung Min Kim ◽  
Yoon Sungho
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Substitution Reaction ◽  
Three Dimensional ◽  
Title Complex ◽  
Rhodium Complex ◽  
Synthetic Route ◽  
Dimensional Network ◽  
Weak Hydrogen Bonds ◽  
Solvent Molecules

The title complex, [Rh(C10H15)Cl(C14H12N2O4)]Cl·2C4H5NO3, has been synthesized by a substitution reaction of the precursor [bis(2,5-dioxopyrrolidin-1-yl) 2,2′-bipyridine-4,4′-dicarboxylate]chlorido(pentamethylcyclopentadienyl)rhodium(III) chloride with NaOCH3. The RhIIIcation is located in an RhC5N2Cl eight-coordinated environment. In the crystal, 1-hydroxypyrrolidine-2,5-dione (NHS) solvent molecules form strong hydrogen bonds with the Cl−counter-anions in the lattice and weak hydrogen bonds with the pentamethylcyclopentadienyl (Cp*) ligands. Hydrogen bonding between the Cp* ligands, the NHS solvent molecules and the Cl−counter-anions form links in a V-shaped chain of RhIIIcomplex cations along thecaxis. Weak hydrogen bonds between the dimethyl 2,2′-bipyridine-4,4′-dicarboxylate ligands and the Cl−counter-anions connect the components into a supramolecular three-dimensional network. The synthetic route to the dimethyl 2,2′-bipyridine-4,4′-dicarboxylate-containing rhodium complex from the [bis(2,5-dioxopyrrolidin-1-yl) 2,2′-bipyridine-4,4′-dicarboxylate]rhodium(III) precursor may be applied to link Rh catalysts to the surface of electrodes.

Ambident Heterocyclic Reactivity: Alkylation of 4-Substituted and 2,4-Disubstituted Benzimidazoles

1994 ◽  
Vol 47 (8) ◽  
pp. 1523 ◽  
Author(s):  
MR Haque ◽  
M Rasmussen
Keyword(s):  
Hydrogen Bonding ◽  
Transition State ◽  
Electrostatic Field ◽  
Transition States ◽  
Alkyl Halides ◽  
Methyl Group ◽  
Site Selectivity ◽  
Leaving Group ◽  
Standard Set ◽  
Specific Association

The N1/N3-alkylation patterns of 4-amino-, 4-methyl- and 4-nitro-benzimidazole anions, and their 2-methyl analogues, with a standard set of primary alkyl halides (in dimethylformamide, 30°) have been determined and compared. The observed regioselectivities are dominated by proximal effects-electrostatic field, non-bonded steric and in some cases specific association (hydrogen bonding)-the interplay of which is critically dependent on the (variable) geometries of the SN2 transition states involved, in particular on the N---C distance of the developing N-alkyl bonds. The presence of a symmetrically placed 2-methyl group produces an enhanced N1/N3 site selectivity, very sensitive to the loose-tight nature of the transition state. Halide leaving group effects on butylation regioselectivities of 2-unsubstituted, 2-ethoxy-, 2-methyl- and 2-chloro-4-methylbenzimidazole anions, whilst small, are consistent with a Bell-Evans-Polanyi analysis of SN2 transition state variations, with the earlier transition states of CH3(CH2)3I leading to reduced regioselectivities.

scholarly journals Synthesis of the symmetrical methylene diesters from carboxylic ionic liquids

2017 ◽  
Vol 95 (7) ◽  
pp. 744-750 ◽  
Author(s):  
D. Gómora-Herrera ◽  
I.V. Lijanova ◽  
O. Olivares-Xometl ◽  
A. Toscano ◽  
N.V. Likhanova
Keyword(s):  
Ionic Liquid ◽  
Hydrogen Bonding ◽  
Ionic Liquids ◽  
Hydrogen Atom ◽  
Crystal Packing ◽  
Spectroscopic Techniques ◽  
Amine Group ◽  
Carboxylic Group ◽  
Microwave Reactor ◽  
Trimer Formation

The reaction between carboxylic ionic liquids and dichloromethane, which provokes the formation of symmetrical methylene diesters, was carried out. The synthesis of these ionic liquid compounds was carried out in a microwave reactor, and the characterization by spectroscopic techniques of methylene diesters (methylene di-2-furoate, methylene di-2-picolinate, methylene dianthranilate, and methylene dioleate) is described and the crystal structures discussed. The crystal packing of methylene dianthranilate is characterized by trimer formation due to hydrogen bonding via interactions between the hydrogen atom of the primary amine group and the oxygen of the carboxylic group.

scholarly journals 2-Aminoterephthalic acidN,N-dimethylformamide disolvate

2012 ◽  
Vol 68 (8) ◽  
pp. o2501-o2501 ◽  
Author(s):  
Stefan Loos ◽  
Wilhelm Seichter ◽  
Edwin Weber ◽  
Florian Mertens
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Amine Group ◽  
Asymmetric Unit ◽  
Solvent Molecules

The asymmetric unit of the title structure, C8H7NO4·2C3H7NO, contains one 2-aminoterephthalic acid and twoN,N-dimethylformamide molecules. Strong O—H...O hydrogen bonds between the acidic carboxy H atoms of 2-aminoterephthalic acid and the O atoms of both solvent molecules form linear 1:2 complex units. One H atom of the amine group is involved in intramolecular N—H...O hydrogen bonding, whereas the second one takes part in an intermolecular N—H...O connection. Furthermore, the crystal is stabilized by weak C—H...O hydrogen bonds.

Rotational isomers of m-cresol and internal rotation of the methyl group in S0, S1, and the ion

1987 ◽  
Vol 91 (22) ◽  
pp. 5589-5593 ◽  
Author(s):  
Hiromi. Mizuno ◽  
Katsuhiko. Okuyama ◽  
Takayuki. Ebata ◽  
Mitsuo. Ito
Keyword(s):  
Internal Rotation ◽  
Methyl Group ◽  
Rotational Isomers
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