Substituent effect in 1-X-decanes and 3-X-gonanes based on core-electron binding energies calculated with density-functional theory

2013 ◽  
Vol 1024 ◽  
pp. 9-14 ◽  
Author(s):  
Yuji Takahata
1996 ◽  
Vol 74 (6) ◽  
pp. 1005-1007 ◽  
Author(s):  
Delano P. Chong

Our recent procedure of computing accurate core-electron binding energies (CEBEs) with density-functional theory is applied to glycine conformers in this work. The procedure uses the unrestricted generalized transition-state model and a combined functional of Becke's 1988 exchange with Perdew's 1986 correlation. When a large basis set such as Dunning's correlation-consistent polarized valence quadruple zeta set is used, the average absolute deviation from experiment for the CEBEs of the most stable conformer of glycine is only 0.2 eV, compared with 18 eV for Koopmans' theorem. Key words: core-electron binding energies, density-functional theory, glycine.


2013 ◽  
Vol 91 (7) ◽  
pp. 637-641 ◽  
Author(s):  
Delano P. Chong

Allopurinol vapour is studied with density functional theory. Using the best method from past experience for each property, we predict the equilibrium geometry, vibrational spectrum, dipole moment, average dipole polarizability, UV absorption spectrum, vertical ionization energies of valence electrons, and core-electron binding energies.


2021 ◽  
Author(s):  
Ian Murphy ◽  
Peter Rice ◽  
Madison Monahan ◽  
Leo Zasada ◽  
Elisa Miller ◽  
...  

Covalent functionalization of Ni2P nanocrystals was demonstrated using aryl-diazonium salts. Spontaneous adsorption of aryl functional groups was observed, with surface coverages ranging from 20-96% depending on the native reactivity of the salt as determined by the aryl substitution pattern. Increased coverage was possible for low reactivity species using a sacrificial reductant. Functionalization was confirmed using thermogravimetric analysis, FTIR and X-ray photoelectron spectroscopy. The structure and energetics of this nanocrystal electrocatalyst system, as a function of ligand coverage, was explored with density functional theory calculations. The Hammett parameter of the surface functional group was found to linearly correlate with the change in Ni and P core-electron binding energies and the nanocrystal’s experimentally and computationally determined work-function. The electrocatalytic activity and stability of the functionalized nanocrystals for hydrogen evolution were also improved when compared to the unfunctionalized material, but a simple trend based on electrostatics was not evident. We used density functional theory to understand this discrepancy and found that H adsorption energies on the covalently functionalized Ni2P also do not follow the electrostatic trend and are predictive descriptors of the experimental results.


2013 ◽  
Vol 12 (01) ◽  
pp. 1250096 ◽  
Author(s):  
DELANO P. CHONG

The molecule 5-methyltetrazole (5MTZ) can exist in two taumeric forms. The vertical ionization energies (VIEs) of both valence and core electrons of both the tautomers are calculated with our established DFT procedures and compared with available experimental data. For the 2H-tautomer, the average absolute deviations (AADs) for the outer-valence VIEs and core-electron binding energies (CEBEs) from experiment are below 0.1 eV, while the AAD for the inner-valence VIEs is much larger at 0.4 eV. For the 1H-tautomer, no observed valence VIEs have been reported and the AAD for the calculated CEBEs is 0.2 eV. The assignment of the experimental core-electron ionization spectrum is confirmed, but our results suggest a slight modification of the assignment of the UV photoelectron spectrum of the 2H-tautomer.


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