All-electron density functional theory calculations of the zero-pressure properties of plutonium dioxide

2000 ◽  
Author(s):  
Jonathan C. Boettger
Keyword(s):  
Density Functional Theory ◽  
Electron Density ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Plutonium Dioxide ◽  
Functional Theory ◽  
Electron Density Functional Theory

Density functional theory study of bis(imino) N-heterocyclic carbene iron(II) complexes

2014 ◽  
Vol 92 (10) ◽  
pp. 925-931 ◽  
Author(s):  
Jameel Al Thagfi ◽  
Gino G. Lavoie
Keyword(s):  
Density Functional Theory ◽  
Electron Density ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Iron Complexes ◽  
Relative Energy ◽  
Iron Complex ◽  
Geometrical Parameters ◽  
Functional Theory ◽  
Imine Group

Density functional theory calculations at the B3LYP/DGDZVP and UB3LYP/TZVP levels were performed on 1,3-bis[1-(2,6-dimethylphenylimino)ethyl]imidazolium and on the corresponding imidazol-2-ylidene iron(II) dichloride complex, respectively. The resulting geometrical parameters of the optimized structures were in good agreement with previously reported X-ray structures. The ground state for the high-spin (quintet multiplicity) iron complex is 82.4 kJ/mol lower in energy compared to the low-spin (triplet) configuration, in agreement with magnetic susceptibility measurements. Further calculations were carried out on related benzimidazol-2-ylidene and pyrimidin-2-ylidene ligands and on the corresponding iron complexes to gain insight into their electronic properties and reactivities. The energy of the highest occupied and lowest unoccupied molecular orbitals of all three carbenes suggests that the pyrimidin-2-ylidene and the benzimidazol-2-ylidene are the best σ-donor and best π-acceptor, respectively. Using those results, the metal center in the pyrimidin-2-ylidene iron dichloride complex was predicted to bear the highest electron density. This was supported by the high relative energy of its highest occupied molecular orbital compared to that of the corresponding imidazole-2-ylidene and benzimidazol-2-ylidene iron complexes. The electrostatic potential maps of all three metal complexes furthermore indicated a marked decrease in electron density for the coordinated imine group, supporting a greater reactivity towards nucleophiles.

Sign in / Sign up

Export Citation Format

Share Document