Hydrogen bonding in organic compounds. IX. Intramolecular actions between the primary amine group and amino, nitro, sulphide, and sulphone groups in aromatic compounds

1964 ◽  
Vol 17 (8) ◽  
pp. 860 ◽  
Author(s):  
AN Hambly ◽  
BV O'Grady
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Organic Compounds ◽  
Aromatic Compounds ◽  
Amine Group ◽  
Intermolecular Hydrogen Bonds ◽  
Amino Derivatives ◽  
Stretching Vibrations ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

Spectroscopic evidence for the existence of intermolecular hydrogen bonds between aniline molecules has been obtained. Examples show the existence of intramolecular hydrogen bonds in orthodiamines, some amino-derivatives of heterocycles, 2-nitro-amines, 2-amino-sulphones, and 2-amino-sulphides. Some new observations, which do not agree with Krueger's interpretation of the profile of the overtone bands due to NH2 stretching vibrations, are recorded.

Hydrogen bonding in organic compounds. II. Amine-cabonyl interactions

1958 ◽  
Vol 11 (4) ◽  
pp. 529 ◽  
Author(s):  
AN Hambly ◽  
J Bonnyman
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Organic Compounds ◽  
Aromatic Compounds ◽  
Primary Amine ◽  
Intermolecular Hydrogen Bonding ◽  
Amine Group ◽  
Methyl Anthranilate ◽  
Infra Red ◽  
Related Compounds

A comparison of the infra-red spectra of typical aromatic compounds, with a primary amine group adjacent to a carbonyl group, with the spectra of related compounds, shows that, in the former, weak hydrogen bonding occurs between the two groups. The strength of the bonds formed is in the order : 1-aminoanthraquinone > 2-amino-acetophenone > methyl anthranilate, and the changes in carbonyl frequency are comparable with those of the symmetric NH2 stretching frequency. Stronger hydrogen bonds are formed in corresponding ortho-acetamido compounds. A brief study of the NH2 stretching frequencies of o-nitroamines in dioxan solution shows that there is considerable interaction between solute and solvent but this cannot be definitely attributed to intermolecular hydrogen bonding.

Hydrogen Bonding in Acid Li-, Ni-, Tetrabutylammonium, and Ammonium Salts of Benzene-1,2,4,5-tetracarboxylic Acid (Pyromellitic Acid)

1992 ◽  
Vol 47 (8) ◽  
pp. 1141-1153 ◽  
Author(s):  
Sven M. Jessen ◽  
Horst Küppers ◽  
Dean C. Luehrs
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Ammonium Salts ◽  
Tetracarboxylic Acid ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
Pyromellitic Acid ◽  
X Ray ◽  
Carboxylic Groups ◽  
Intramolecular Hydrogen

Four acid salts of pyromellitic acid (benzene-1,2,4,5-tetracarboxylic acid) have been synthesized and studied by X-ray diffraction and IR spectroscopy. (1) Dilithium dihydrogen pyromellitate pentahydrate, Li2[C6H2(COO)4H2]· 5H2O; monoclinic, P21/m, a = 6.214(2), b = 19.647(7), c = 6.592(2)Å, β = 115.90(2)°, Ζ = 2, R = 0.068, Rw = 0.067. (2) Hexaaquanickel dihydrogen pyromellitate, [Ni(H2O)6][C6H2(COO)4H2]; monoclinic, P2/m, a = 6.528(1), b = 9.927(2), c = 6.472(1)Å, β = 115.57(1)°, Z = 1, R = 0.044, Rw = 0.039. (3) Tetrabutylammonium trihydrogen pyromellitate, [(C4H9)4N][C6H2(COO)4H3]; monoclinic, P21/c, a = 9.719(4), b = 18.823(8), c = 15.795(5)Å, β = 107.42(3)°, Z = 4, R = 0.059, Rw = 0.039. (4) Diammonium dihydrogen pyromellitate, [NH4]2[C6H2(COO)4H2]; monoclinic, P21/c, a = 4.7665(6), b = 11.681(3), c = 10.149(2)Å, ß = 102.19(2)°, Z = 2, R = 0.045, Rw = 0.039. Compounds 1, 2, and 3 show very short intramolecular hydrogen bonds between adjacent carboxylic groups (O ••• O distances 2.384(6), 2.386(5), 2.387(3)Å, respectively). Compound 4 forms intermolecular hydrogen bonds (O ··· O distance 2.642(2) A). The different hydrogen bonding modes are also evident in the IR spectra.

Etude spectroscopique des dérivés du peroxyde d'hydrogène. IV. L'acide de Caro, H2SO5

1970 ◽  
Vol 48 (24) ◽  
pp. 3903-3910 ◽  
Author(s):  
José L. Arnau ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonding ◽  
Hydroxyl Groups ◽  
Intermolecular Hydrogen Bonds ◽  
Laser Raman ◽  
Laser Raman Spectra ◽  
Intramolecular Hydrogen ◽  
First Time ◽  
Lattice Modes

The i.r. and laser Raman spectra of pure, crystalline Caro's acid, H2SO5, were measured for the first time between 4000 and 30 cm−1. Most of the fundamental vibrations of the molecule could be identified by comparison with those of the H2SO4, H2O2 and HSO5− species. In addition, a dozen or so of lattice modes were recorded. The O—O stretching frequency is slightly higher (886 cm−1) than in solid H2O2, contrary to expectation. The two hydroxyl groups are quite different, both chemically (Caro's acid is essentially monobasic) and spectroscopically. The ionizable OH group forms strong intermolecular hydrogen bonds, as in H2SO4. However, the non-ionizable O2H group is engaged mainly in intramolecular hydrogen bonding. The unit cell of the crystalline acid must contain more than two molecules.

scholarly journals Intramolecular Hydrogen Bonds in Selected Aromatic Compounds: Recent Developments

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 909
Author(s):  
Aneta Jezierska ◽  
Peter M. Tolstoy ◽  
Jarosław J. Panek ◽  
Aleksander Filarowski
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Aromatic Compounds ◽  
Mannich Base ◽  
Intramolecular Hydrogen Bonding ◽  
Mannich Bases ◽  
Intramolecular Hydrogen Bonds ◽  
Recent Developments ◽  
Physicochemical Features ◽  
Intramolecular Hydrogen

A review of intramolecular hydrogen bonding in ortho-hydroxyaryl Schiff bases, ortho-hydroxyaryl Mannich bases, dipyrrins, ortho-hydroxyaryl ketones, ortho-hydroxyaryl amides, and 4-Bora-3a,4a-diaza-s-indacene (BODIPY) dyes with tautomeric sensors as substituents is presented in this paper. Ortho-hydroxy Schiff and Mannich base derivatives are known as model molecules for analysing the properties of intramolecular hydrogen bonding. The compounds under discussion possess physicochemical features modulated by the presence of strong intramolecular hydrogen bonds. The equilibrium between intra- and inter-molecular hydrogen bonds in BODIPY is discussed. Therefore, the summary can serve as a knowledge compendium of the influence of the hydrogen bond on the molecular properties of aromatic compounds.

Hydrogen bonds in derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea

1991 ◽  
Vol 56 (4) ◽  
pp. 880-885 ◽  
Author(s):  
Oľga Hritzová ◽  
Dušan Koščík
Keyword(s):  
Hydrogen Bonds ◽  
Spectral Studies ◽  
Intramolecular Hydrogen Bonds ◽  
Tautomeric Forms ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

Intramolecular hydrogen bonds of the N-H···O=C type have been detected in the derivatives of N-substituted N’-benzoyl- and N’-(2-chlorobenzoyl)thiourea on the basis of IR spectral studies. The title compounds can exist in two tautomeric forms.

The syntheses of 6-C-alkyl derivatives of methyl α-isomaltoside for a study of the mechanism of hydrolysis by amyloglucosidase

2001 ◽  
Vol 79 (2) ◽  
pp. 238-255 ◽  
Author(s):  
Ulrike Spohr ◽  
Nghia Le ◽  
Chang-Chun Ling ◽  
Raymond U Lemieux
Keyword(s):  
Hydrogen Bonds ◽  
Molecular Model ◽  
Aromatic Amino Acids ◽  
Hydroxyl Group ◽  
Bulk Solution ◽  
Anomeric Effect ◽  
Nmr Studies ◽  
Intermolecular Hydrogen Bonds ◽  
Model Calculations ◽  
Derivatives Of

The epimeric (6aR)- and (6aS)-C-alkyl (methyl, ethyl and isopropyl) derivatives of methyl α-isomaltoside (1) were synthesized in order to examine the effects of introducing alkyl groups of increasing bulk on the rate of catalysis for the hydrolysis of the interunit α-glycosidic bond by the enzyme amyloglucosidase, EC 3.2.1.3, commonly termed glucoamylase (AMG). It was previously established that methyl (6aR)-C-methyl α-isomaltoside is hydrolysed about 2 times faster than methyl α-isomaltoside and about 8 times faster than its S-isomer. The kinetics for the hydrolyses of the ethyl and isopropyl analogs were also recently published. As was expected from molecular model calculations, all the R-epimers are good substrates. A rationale is presented for the catalysis based on conventional mechanistic theories that includes the assistance for the decomposition of the activated complex to products by the presence of a hydrogen bond, which connects the 4a-hydroxyl group to the tryptophane and arginine units. It is proposed that activation of the initially formed complex to the transition state is assisted by the energy released as a result of both of the displacement of perturbed water molecules of hydration at the surfaces of both the polyamphiphilic substrate and the combining site and the establishment of intermolecular hydrogen bonds, i.e., micro-thermodynamics. The dissipation of the heat to the bulk solution is impeded by a shell of aromatic amino acids that surround the combining site. Such shields are known to be located around the combining sites of lectins and carbohydrate specific antibodies and are considered necessary to prevent the disruption of the intermolecular hydrogen bonds, which are of key importance for the stability of the complex. These features together with the exquisite stereoelectronic dispositions of the reacting molecules within the combining site offer a rationalization for the catalysis at ambient temperatures and near neutral pH. The syntheses involved the addition of alkyl Grignard reagents to methyl 6-aldehydo-α-D-glucopyranoside. The addition favoured formation of the S-epimers by over 90%. Useful amounts of the active R-isomers were obtained by epimerization of the chiral centers using conventional methods. Glycosylation of the resulting alcohols under conditions for bromide-ion catalysis, provided methyl (6aS)- and (6aR)-C-alkyl-hepta-O-benzyl-α-isomaltosides. Catalytic hydrogenolysis of the benzyl groups afforded the desired disaccharides. 1H NMR studies established the absolute configurations and provided evidence for conformational preferences.Key words: amyloglucosidase (AMG), exo-anomeric effect, 6-C-alkyl-α-D-glucopyranosides and isomaltosides, mechanism of enzyme catalysis.

Beziehungen zwischen Rotationsisomerie, Wasserstoffbrücken-Bindung und Substituenteneffekten der organischen Chemie / Relations between Rotational Isomerism, Hydrogen Bonding, and Substituent Effects in Organic Chemistry

1972 ◽  
Vol 27 (6) ◽  
pp. 663-674 ◽  
Author(s):  
Gotthard H. Krause ◽  
Herbert Hoyer
Keyword(s):  
Hydrogen Bonding ◽  
Substituent Effects ◽  
Intramolecular Hydrogen Bonding ◽  
Rotational Isomerism ◽  
Proton Acceptor ◽  
Single Bond ◽  
Free Enthalpy ◽  
Acceptor Group ◽  
Intramolecular Hydrogen ◽  
Derivatives Of

The change of free enthalpy involved in intramolecular hydrogen bonding is smaller if the proton acceptor group can rotate round a single bond, as compared to proton acceptor groups which are fixed in a position optimal for hydrogen bonding. Also, the free enthalpy change is altered when the rotation of the proton acceptor is sterically restricted. This is demonstrated by comparing the absorptions of carbonyl stretching vibrations in the infrared spectra of certain compounds showing rotational isomerism. In the present study derivatives of 5-hydroxy-2,2-dimethyl-6-carbomethoxychromanone- (4), 3-nitrosalicylaldehyde and 3-nitro-2-hydroxy-acetophenones substituted in the position 5 and 6 are examined.

scholarly journals The Effects of the Solvents on the Macrocyclic Structures: From Rigid Pillararene to Flexible Crown Ether

2021 ◽  
Author(s):  
Shuangshuang Wang ◽  
Yanzhen Yin ◽  
Jian Gao ◽  
Xingtang Liang ◽  
Haixin Shi
Keyword(s):  
Hydrogen Bonds ◽  
Structural Design ◽  
Structural Features ◽  
Intermolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
Effect Of Solvents ◽  
Dynamics Simulations ◽  
Intramolecular Hydrogen ◽  
Macrocyclic Molecules ◽  
Polarity Of Solvents

The differences in the macrocyclic structures lead to different flexibilities, and yet the effect of solvents on the conformations is not clear so far. In this work, the conformations of four representational macrocyclic molecules (pillar[5]arene, p-tert-butyl calix[6]arene, benzylic amide macrocycle and dibenzo-18-crown-6) in three solvents with distinct polarity have been studied by all-atom molecular dynamics simulations. The structural features of the macrocycles in the solvents indicate that the conformations are related to the polarity of the solvents and the formation of hydrogen bonds. For the pillar[5]arene, the benzylic amide macrocycle and the dibenzo-18-crown-6, that cannot form intramolecular hydrogen bonds, the polarity of solvents is the major contributing factor in the conformations. The formation of intramolecular hydrogen bonds, in contrast, determinates the conformations of the calix[6]arene. Furthermore, the slight fluctuations of the structures will result in tremendous change of the intramolecular hydrogen bonds of the macrocycles and the intermolecular hydrogen bonds between the macrocycles and the solvents. The current theoretical studies that serve as a basis for the macrocyclic chemistry are valuable for the efficient structural design of the macrocyclic molecules.

Sign in / Sign up

Export Citation Format

Share Document