Computational Study and Molecular Orbital Analysis of NMR Shielding, Spin–Spin Coupling, and Electric Field Gradients of Azido Platinum Complexes

2012 ◽  
Vol 134 (32) ◽  
pp. 13374-13385 ◽  
Author(s):  
Kiplangat Sutter ◽  
Jochen Autschbach
Keyword(s):  
Electric Field ◽  
Molecular Orbital ◽  
Computational Study ◽  
Platinum Complexes ◽  
Spin Coupling ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Molecular Orbital Analysis ◽  
Spin Spin Coupling ◽  
Orbital Analysis

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.

Effects of non-axial electric field gradients on the ferromagnetic state of amorphous rare-earth alloys

1980 ◽  
Vol 58 (5) ◽  
pp. 629-632 ◽  
Author(s):  
H. Hernandez ◽  
R. Ferrer ◽  
M. J. Zuckermann
Keyword(s):  
Rare Earth ◽  
Electric Field ◽  
Ferromagnetic State ◽  
Rare Earth Alloys ◽  
Electric Field Gradients ◽  
Axial Electric Field ◽  
Ferromagnetic Alloys ◽  
Field Gradients ◽  
Ordered State

We discuss the influence of non-axial electric field gradients on the ordered state of amorphous ferromagnetic alloys containing rare-earth atoms.

Sign in / Sign up

Export Citation Format

Share Document