Conventional frontier molecular orbital theory is not able to satisfactorily explain the regioselectivity outcome of the nitrilimine-alkene cycloaddition. We considered that conceptual density functional theory (DFT) could be an effective theoretical framework to rationalize the regioselectivity of the title reaction. Several nitrilimine-alkene cycloadditions were analyzed, for which we could f...

The structural properties of the uranium-encapsulated nano-cage U@Au14 are predicted using density functional theory. The presence of the uranium atom makes the Au14 structure more stable than the empty Au14-cage, with a triplet ground electronic state for U@Au14. Analysis of the electronic structure shows that the two frontier single-occupied molecular orbital electrons of U@Au14 mainly origin...

Quantum chemical calculations using the density functional theory (DFT) at the B3LYP/6-31G(d,p) level were performed ontwo quinoxaline derivatives named: 1-ethyl-3-methylquinoxalin-2(1H)-one (Et-N-Q=O) and 1benzyl-3-methylquinoxalin-2(1H)-one (Bz-N-Q=O) in order to correlate the structural and electronic properties, such as HOMO, LUMO energy values, frontier orbital energy gap, molecular dipole...

We address the nature of the bond between water molecules and metal surfaces through a systematic density-functional theory (DFT) study of H(2)O monomer adsorption on a series of close-packed transition metal surfaces: Ru(0001), Rh(111), Pd(111), and Ag(111). Aiming to understand the origin behind energetic and structural trends along the 4d series we employ a range of analysis tools such as th...

In the present study 3-(2-Furyl) Propionicacid (C7H8O3) abbreviated as 32FPA which has biological applications had been investigated with Density functional theory calculations with Gaussian 03 software package. The FT-IR, FT-Raman, NMR spectra of the title compound was recorded and analyzed. The equilibrium geometry, bonding features and harmonic vibrational wave numbers were investigated with...

We have recently reported on a small organic molecule containing a bithiophene core with end-capping phthalimide units (PthTh2Pth) that exhibited a H-aggregation tendency in the solid state and high electron mobility in organic field effect transistors. In this contribution, we have studied both the physical and electrical properties of poly(3-hexylthiophene) (P3HT) and PthTh2Pth thin films by ...

Small cationic Au(n)Cu(m)+ (n + m < or = 6) clusters and their monocarbonyls Au(n)Cu(m)CO+ have been studied by first-principles calculations. The trend for small Au clusters to form planar structures is weaker when some Au atoms are substituted by Cu atoms. A significant odd-even oscillation of the electron affinity of the cationic clusters with the number of their Au or Cu atoms is observed. ...

The spectrum-detected smallest sulfide clusterfullerene Sc2S@C68 has not been characterized yet. Herein, we explored a series of Sc2S@C68 species to determine which could be the most promising isomer. The results suggest that a sulfide cluster encapsulated in the C2v(6073)-C68 cage which violates the isolated pentagon rule (IPR) with two opposite pentalenes has the lowest energy and an overwhel...

Quantum calculations of the physical properties (electronic and vibrational), based on density functional theory (DFT) method at B3LYP/6-31G** level of theory, were performed, by means of the Gaussian 09 set of programs, to investigate the effect of the addition of the radical CN on pyridazine molecules. The best geometry, the total energy, frontier molecular orbital energies (HOMO and HUMO), e...

The density functional theory (DFT) and time-dependent DFT (TD-DFT) methodologies have been applied to explore on a series of star-shaped π-conjugated organoboron systems for organic light-emitting diode (OLED) materials. The compounds under investigation consist of benzene as π-bridge and different core units and triarylboron end groups. Their geometry structures, frontier molecular orbital (F...