Etude par spectroscopie infrarouge de l'ion diacétylacétylium. Rôle de AlCl3, AlBr3 et GaCl3 sur sa formation et sa structure. Mise en évidence d'une liaison hydrogène intramoléculaire dans le tétrachloroaluminate de diacétylacétylium

1977 ◽  
Vol 55 (17) ◽  
pp. 3096-3104 ◽  
Author(s):  
Alain Germain ◽  
Jean-Louis Pascal ◽  
Jacqueline Potier
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Lewis Acids ◽  
Intramolecular Hydrogen ◽  
Identical Behaviour

The study of the reaction of formation of the diacetoacetylium ion from CH3COX (X = Cl or Br) and the Lewis acids AlCl3, AlBr3, and GaCl3 shows that the counterion is always the tetrahalogenometallate. In the solid tetrachloroaluminate the cation is a monomer with a double minimum type of intramolecular hydrogen bond: v O—H—O = v O—D—O = 1400 cm−1; d O—O = 2.48 Å. An identical behaviour is observed with the tetrabromoaluminate, but the structure of the diacetoacetylium sstetrachlorogallate is more complicated.

Effect of the intramolecular hydrogen bond in the active metabolite analogs of leflunomide for blocking the Plasmodium falciparum dihydroorotate dehydrogenase enzyme: QTAIM, NBO, and docking study

2020 ◽  
Vol 16 ◽  
Author(s):  
Reihaneh Heidarian ◽  
Mansoureh Zahedi-Tabrizi
Keyword(s):  
Hydrogen Bond ◽  
Plasmodium Falciparum ◽  
Molecular Orbital ◽  
Intramolecular Hydrogen Bond ◽  
Active Metabolite ◽  
Chemical Hardness ◽  
Dihydroorotate Dehydrogenase ◽  
Molecular Orbital Analysis ◽  
Intramolecular Hydrogen ◽  
Orbital Analysis

: Leflunomide (LFM) and its active metabolite, teriflunomide (TFM), have drawn a lot of attention for their anticancer activities, treatment of rheumatoid arthritis and malaria due to their capability to inhibit dihydroorotate dehydrogenase (DHODH) and Plasmodium falciparum dihydroorotate dehydrogenase (PfDHODH) enzyme. In this investigation, the strength of intramolecular hydrogen bond (IHB) in five analogs of TFM (ATFM) has been analyzed employing density functional theory (DFT) using B3LYP/6-311++G (d, p) level and molecular orbital analysis in the gas phase and water solution. A detailed electronic structure study has been performed using the quantum theory of atoms in molecules (QTAIM) and the hydrogen bond energies (EHB) of stable conformer obtained in the range of 76-97 kJ/mol, as a medium hydrogen bond. The effect of substitution on the IHB nature has been studied by natural bond orbital analysis (NBO). 1H NMR calculations show an upward trend in the proton chemical shift of the enolic proton in the chelated ring (14.5 to 15.7ppm) by increasing the IHB strength. All the calculations confirmed the strongest IHB in 5-F-ATFM and the weakest IHB in 2-F-ATFM. Molecular orbital analysis, including the HOMO-LUMO gap and chemical hardness, was performed to compare the reactivity of inhibitors. Finally, molecular docking analysis was carried out to identify the potency of inhibition of these compounds against PfDHODH enzyme.

scholarly journals CP/MASS 13C NMR Spectra of Cellulose Solids: An Explanation by the Intramolecular Hydrogen Bond Concept

1985 ◽  
Vol 17 (5) ◽  
pp. 701-706 ◽  
Author(s):  
Kenji Kamide ◽  
Kunihiko Okajima ◽  
Keisuke Kowsaka ◽  
Toshihiko Matsui
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Intramolecular Hydrogen

(1′R,3S)-2-Oxo-1-(1′-phenylethyl)piperidine-3-carboxylic acid: a case of a very strong intramolecular hydrogen bond

2004 ◽  
Vol 60 (11) ◽  
pp. o2110-o2112
Author(s):  
Ana-María Lumbreras-García ◽  
Alberto Galindo-Guzmán ◽  
Dino Gnecco ◽  
Joel-Luis Terán ◽  
Sylvain Bernès
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Intramolecular Hydrogen Bond ◽  
Intramolecular Hydrogen ◽  
Strong Intramolecular Hydrogen Bond

A photochromic naphthopyran dye activated by the intramolecular hydrogen bond and its photodynamics in the ormosil matrix coating

2014 ◽  
Vol 73 (2) ◽  
pp. 293-298 ◽  
Author(s):  
Yongzeng Fang ◽  
Qinghua Meng ◽  
Zhen Wang ◽  
Guoqing Wang ◽  
Hong Jiang ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Intramolecular Hydrogen Bond ◽  
Intramolecular Hydrogen
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