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Unoccupied Orbital Energies Of 1,4-Benzenedithiol And The Homo–Lumo Gap, Adam M. Scheer, Gordon A. Gallup, Paul Burrow
Unoccupied Orbital Energies Of 1,4-Benzenedithiol And The Homo–Lumo Gap, Adam M. Scheer, Gordon A. Gallup, Paul Burrow
Paul Burrow Publications
The energies of the temporary anion states of 1,4-benzenedithiol (BDT) are determined by electron scattering and compared with those computed by density functional theory (DFT) and Hartree–Fock (HF) methods. Using semi-empirical scalings derived from the ionization energies and electron affinities of a series of phenyl–ethynyl compounds, we compute the HOMO–LUMO energy gap of BDT. We show that without such scalings the gap is substantially underestimated using DFT and overestimated using HF methods. Scaled gaps are also determined for several related compounds and compared with experimental measurements in the literature.
Are There Π* Shape Resonances In Electron Scattering From Phosphate Groups?, Paul Burrow, Gordon A. Gallup, Alberto Modelli
Are There Π* Shape Resonances In Electron Scattering From Phosphate Groups?, Paul Burrow, Gordon A. Gallup, Alberto Modelli
Paul Burrow Publications
The temporary anion states of trimethyl phosphate and several compounds bearing the P=O group were explored using electron transmission spectroscopy and ab initio calculations to determine if these states have the characteristics of the π* resonances usually associated with multiple bonds. No evidence was found for this in (CH3O)3PO and, by extension, we do not expect them to appear in the phosphate group of DNA. Cl3PO, however, does display such characteristics to some extent, and we show that they arise from the spatial properties of the π* (P-Cl) orbitals rather than from multiple PO …