Abstract In the present study, 3- p -methoxybenzyl/ m -chlorobenzyl/phenyl-4-(3-methyl-2-thienylmethyleneamino)-4,5-dihydro-1 H -1,2,4-triazol-5-ones were obtained from reaction between 3-methylthiophene-2-carbaldehyde and three different 4-amino-(3- -chlorobenzyl/phenyl)-4,5-dihydro-1 -1,2,4-triazole-5-ones. order to compare experimental theoretical values, geometric parameter, electronic, non...

Recently, we have proposed an approach for finding the valence anion ground state, based on the stabilization exerted by a polar solvent; the methodology used standard DFT methods and relatively inexpensive basis sets and yielded correct electron affinity (EA) values by gradually decreasing the dielectric constant of the medium. In order to address the overall performance of the new methodology...

Theoretical prediction of electronic spectra of uranium-containing complexes remains quite a challenge for quantum chemistry since it requires an accurate treatment of both correlation and relativistic effects at the same time. While reliable electronic excitation energies can be obtained from correlated wave function approaches that take relativistic effects into account, they are, however, li...

Flavonoids are polyphenolic plant secondary metabolites with biological properties including Alzheimer's disease (AD) inhibition activities. Numerous studies have been conducted on naturally occurring flavonoids modified to obtain effective drugs for the management of AD. In this study, DFT/B3PW91, TD-DFT/B3LYP methods target molecule hispidulin 4′,5,7-Trihydroxy-6-Methoxyflavone (THMF) and LAN...

Time-dependent density functional theory (TD-DFT) and single-excitation configuration interaction (CIS) calculations on the electronic excitations in pyrrole have been performed to examine the reliability of these first-principles electronic structure methods in predicting electronic excitation spectra of pyrrole-containing compounds. Both the TD-DFT and CIS calculations led to satisfactory res...

Time-dependent density functional theory (TD-DFT) is applied to the UV-vis absorption and circular dichroism (CD) spectra of a series of transition metals (M=Ru, Zn, Fe) complexed with an enantiopure hemicage ligand, (-)-(5R,5'R,5' 'R,7R,7'R,7' 'R,8S,8'S,8' 'S)-8,8',8' '-[(2,4,6-trimethyl-1,3,5-benzenetriyl)tris(methylene)]tris[5,6,7,8-tetrahydro-6,6-dimethyl-3-(2-pyridinyl)-5,7-methanoisoquino...

The electronic spectrum of alternant polycyclic aromatic hydrocarbons (PAHs) includes two singlet excited states that are often denoted (1)La and (1)Lb. Time-dependent density functional theory (TD-DFT) affords reasonable excitation energies for the (1)Lb state in such molecules, but often severely underestimates (1)La excitation energies and fails to reproduce observed trends in the (1)La exci...

We have investigated the dependence of the static first hyperpolarizability on the bond-length alternation (BLA) parameter. Our analysis indicates that the validity of the first hyperpolarizability/BLA parameter relationship is restricted to the no-field, vacuum, limit, while it successively breaks down along with increasing polarity of a surrounding medium, becoming invalid, for instance, in a...