scholarly journals Charge-transfer Character in the Intramolecular Hydrogen Bond: Electronic Structures and Spectra of Hydrogen Maleate Anion and Related Molecules

1977 ◽  
Vol 50 (3) ◽  
pp. 645-649 ◽  
Author(s):  
Hiroshi Morita ◽  
Kiyokazu Fuke ◽  
Saburo Nagakura
Keyword(s):  
Hydrogen Bond ◽  
Charge Transfer ◽  
Intramolecular Hydrogen Bond ◽  
Electronic Structures ◽  
Intramolecular Hydrogen

Intramolecular hydrogen bond – enhanced electroluminescence performance of hybridized local and charge transfer (HLCT) excited-state blue-emissive materials

2021 ◽  
Author(s):  
Wan Li ◽  
Pongsakorn Chasing ◽  
Wachara Benchaphanthawee ◽  
Phattananawee Nalaoh ◽  
Thanyarat Chawanpunyawat ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Excited State ◽  
Charge Transfer ◽  
Intramolecular Hydrogen Bond ◽  
Utilization Efficiency ◽  
High Brightness ◽  
Singlet Exciton ◽  
High Maximum ◽  
Intramolecular Hydrogen

OLED devices based on o-hydroxyphenyl phenanthroimidazole (HPI) emitters showed a high maximum external quantum effciency of 8.13% with high brightness of 18 100 cd m−2 and a maximum singlet exciton utilization efficiency of as high as 94%.

scholarly journals Reactivity Sites in Dopamine Depend on its Intramolecular Hydrogen Bond

2017 ◽  
Vol 61 (3) ◽  
Author(s):  
Erwin Garcı́a-Hernández ◽  
Jorge Garza
Keyword(s):  
Hydrogen Bond ◽  
Charge Transfer ◽  
Intramolecular Hydrogen Bond ◽  
Transfer Process ◽  
Basis Sets ◽  
Charge Transfer Process ◽  
Oh Groups ◽  
Intramolecular Hydrogen ◽  
Catechol Moiety ◽  
Oxygen Atoms

In this work, three conformers of dopamine were theoretically analyzed, two of them forming an intramolecular hydrogen bond between OH groups in the catechol moiety, the third one without this interaction. The used theoretical method was based on the Kohn-Sham method within the hybrid exchange-correlation functionals without empirical parameters, PBE0. The molecular geometry obtained by this method was contrasted with that obtained from the second-order many-body perturbation theory (MP2) method and the 6-31+G(d), 6-311+G(d) and 6-311++G(d,p) basis sets. Global reactivity descriptors were predicted by using only the PBE0/6-311++G(d,p) method. This method revealed that dopamine is not a good acceptor of electrons. Thus, in one charge transfer process, this compound prefers donating electrons, as observed experimentally. All global chemical predictors do not show important changes regardless of the presence of an intramolecular hydrogen bond. However, in the case of local reactivity predictors, oxygen atoms of the catechol moiety exhibit changes when this contact is present. This conclusion was confirmed when 8 catechol derivatives were analyzed with the same procedure applied over the dopamine. Additionally, the carbon atoms opposite to the carbon atoms linked to oxygen atoms, in the catechol moiety, present the biggest changes when these systems donate one electron. Consequently, the electron involved during the charge transfer process of these systems will be detached from the region defined between these two carbon atoms.

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
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