Synthesis and spectroscopic study of aminals derived from 8-aminoquinoline

1982 ◽  
Vol 60 (13) ◽  
pp. 1775-1779 ◽  
Author(s):  
Juana Bellanato ◽  
Enrique Galvez ◽  
Rosario Escobar ◽  
Jose Manuel Cano-Pavon
Keyword(s):  
Hydrogen Bonding ◽  
Schiff Base ◽  
Spectroscopic Study ◽  
Mass Spectra ◽  
Intramolecular Hydrogen Bonding ◽  
H Nmr ◽  
Intramolecular Hydrogen

Treating 8-aminoquinoline with di-2-pyridyl ketone, pyridine-2-carboxaldehyde, or 6-methylpyridine-2-carboxaldehyde leads to the formation of the corresponding aminal instead of the expected Schiff base. The ir, 1H nmr, and mass spectra of these compounds are described and discussed.Infrared and 1H nmr analyses indicate that these aminals enjoy intramolecular hydrogen bonding. This effect is considered to contribute significantly to their unusual stability.

scholarly journals Intra-molecular Interactions in Porous Covalent Organic Frameworks

2014 ◽  
Vol 70 (a1) ◽  
pp. C530-C530
Author(s):  
Rahul Banerjee
Keyword(s):  
Hydrogen Bonding ◽  
Schiff Base ◽  
Molecular Interactions ◽  
Chemical Stability ◽  
Intramolecular Hydrogen Bonding ◽  
Covalent Organic Frameworks ◽  
Covalent Organic Framework ◽  
New Strategy ◽  
The Stability ◽  
Intramolecular Hydrogen

A new strategy of intramolecular hydrogen bonding in 2D covalent organic framework as an extra stabilizing factor has been introduced, which helps to improve the crystallinity, porosity and chemical stability of the COF. Using this concept, highly stable porphyrin containing covalent organic frameworks have been synthesized using the Schiff base reaction. The stability of the COFs mainly arises due to the strong intramolecular O-H...N=C hydrogen bonding. Validation of this postulate was cross-checked by synthesizing methoxy (OCH3) substituted COF in which no hyrogen bonding exists. It was found that methoxy substituted COF have a low crystallinity, porosity and chemical stability as compared to hydrogen bonded COF.

scholarly journals Multicentered hydrogen bonding in 1-[(1-deoxy-β-D-fructopyranos-1-yl)azaniumyl]cyclopentanecarboxylate (`D-fructose-cycloleucine')

2019 ◽  
Vol 75 (8) ◽  
pp. 1096-1101 ◽  
Author(s):  
Valeri V. Mossine ◽  
Charles L. Barnes ◽  
Thomas P. Mawhinney
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Side Chain ◽  
Slow Rotation ◽  
H Nmr ◽  
Compound C ◽  
Nmr Data ◽  
Cyclopentane Ring ◽  
Intramolecular Hydrogen ◽  
Hydroxy Groups

The title compound, C12H21NO7, (I), is conformationally unstable; the predominant form present in its solution is the β-pyranose form (74.3%), followed by the β- and α-furanoses (12.1 and 10.2%, respectively), α-pyranose (3.4%), and traces of the acyclic carbohydrate tautomer. In the crystalline state, the carbohydrate part of (I) adopts the 2 C 5 β-pyranose conformation, and the amino acid portion exists as a zwitterion, with the side chain cyclopentane ring assuming the E 9 envelope conformation. All heteroatoms are involved in hydrogen bonding that forms a system of antiparallel infinite chains of fused R 3 3(6) and R 3 3(8) rings. The molecule features extensive intramolecular hydrogen bonding, which is uniquely multicentered and involves the carboxylate, ammonium and carbohydrate hydroxy groups. In contrast, the contribution of intermolecular O...H/H...O contacts to the Hirshfeld surface is relatively low (38.4%), as compared to structures of other D-fructose-amino acids. The 1H NMR data suggest a slow rotation around the C1—C2 bond in (I), indicating that the intramolecular heteroatom contacts survive in aqueous solution of the molecule as well.

Synthesis and intramolecular hydrogen bonding of syn-9-hydroxy-18-substituted [3.3]metacyclophanes

2012 ◽  
Vol 90 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Kazuya Tazoe ◽  
Xing Feng ◽  
Bigyan Sharma ◽  
Shinpei Miyamoto ◽  
Takehiko Yamato
Keyword(s):  
Hydrogen Bonding ◽  
Coupling Reaction ◽  
Sodium Hydride ◽  
Intramolecular Hydrogen Bonding ◽  
Aromatic Rings ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Low Field ◽  
Field Shift ◽  
Intramolecular Hydrogen

Various anti-9-methoxy[3.3]metacyclophane-2,11-diones are exclusively obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl)benzenes and 2,6-bis[2-isocyano-2-(tolylsulfonyl)ethyl]-4-tert-butylanisole in dimethylformamide (DMF) with an excess of sodium hydride, from which the corresponding syn-[3.3]metacyclophanes (MCPs) are synthesized via anti/syn-isomerization during the Wolff–Kishner reduction. Demethylation of syn-9-methoxy[3.3]MCPs with BBr3 afforded the corresponding syn-9-hydroxy[3.3]MCPs in good yields. The existence of the strong intramolecular hydrogen bonding between the 9-hydroxy group and the 18-substituents, such as F, OH, and OMe groups at the opposing aromatic rings, are observed in solution and in the solid state. A distinct low-field shift of the phenolic OH proton was observed in the 1H NMR spectrum compared with that of the 18-unsubstituted analog. Furthermore, O–H···F through-space coupling was observed.

Spectral properties and intramolecular hydrogen bonding in 1-methyl(phenyl)-4(5)-substituted 6-oxo-1H-pyridazin-4(5)-ols

1980 ◽  
Vol 45 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Štefan Kováč ◽  
Václav Konečný
Keyword(s):  
Hydrogen Bonding ◽  
Spectral Data ◽  
Spectral Properties ◽  
Intramolecular Hydrogen Bonding ◽  
H Nmr ◽  
Substituent Constants ◽  
Intramolecular Hydrogen ◽  
Hydrogen Bondings ◽  
Methyl Phenyl

Infrared, ultraviolet and 1H-NMR spectral data of 53 1-methyl(phenyl)-4(5)-substituted 6-oxo-1H-pyridazin-4(5)-ols are listed. Intramolecular hydrogen bondings are discussed; relatively strong hydrogen bondings OH...S were found, which are comparable in terms of strength with those of OH...O=C. Wavenumbers of ν(C=O) and ν(O-H) bands linearly correlated with substituent constants σ*, σR and σF.

Theoretical study of intramolecular hydrogen bonding and molecular geometry of 2-trifluoromethylphenol

10.1002/jcc.2 ◽  
1996 ◽  
Vol 17 (16) ◽  
pp. 1804-1819 ◽  
Author(s):  
Attila Kov�cs ◽  
Istv�n Kolossv�ry ◽  
G�bor I. Csonka ◽  
Istv�n Hargittai
Keyword(s):  
Hydrogen Bonding ◽  
Theoretical Study ◽  
Molecular Geometry ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

Intramolecular Hydrogen Bonding Facilitates Electrocatalytic Reduction of Nitrite in Aqueous Solutions

2019 ◽  
Vol 58 (14) ◽  
pp. 9443-9451 ◽  
Author(s):  
Song Xu ◽  
Hyuk-Yong Kwon ◽  
Daniel C. Ashley ◽  
Chun-Hsing Chen ◽  
Elena Jakubikova ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Aqueous Solutions ◽  
Intramolecular Hydrogen Bonding ◽  
Electrocatalytic Reduction ◽  
Intramolecular Hydrogen

Seven-Membered Intramolecular Hydrogen Bonding of Phenols: Database Analysis and Phloroglucinol Model Compounds

2012 ◽  
Vol 2012 (24) ◽  
pp. 4483-4492 ◽  
Author(s):  
Ronald K. Castellano ◽  
Yan Li ◽  
Edwin A. Homan ◽  
Andrew J. Lampkins ◽  
Iris V. Marín ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Intramolecular Hydrogen Bonding ◽  
Model Compounds ◽  
Database Analysis ◽  
Intramolecular Hydrogen
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