UNLABELLED Many chemical concepts hinge on the notion of an orbital called the lowest unoccupied molecular orbital, or LUMO. This hypothetical orbital and the much more concrete highest occupied molecular orbital (HOMO) constitute the two "frontier orbitals", which rationalize a great deal of chemistry. A viable LUMO candidate should have a sensible energy value, a realistic shape with amplitud...

A combined theoretical and experimental study was performed on diarylethenes and diarylethene-capped sexithiophenes aiming at an improved understanding of the electrochemical and photochemical ring-opening and ring-closing mechanisms. Theoretical calculations, based on DFT and TDDFT, suggested that the spatial distribution and the occupancy of the frontier orbitals determine and control the dia...

Open-shell fragments of graphene have attracted increased attention in recent years because oftheir unique spin carrier property. Through the experimental efforts, these neutral π-radicals could bestabilized by steric protection or delocalized π-conjugated system, such as the phenalenyl-basedmolecules. Here, we use zero sum rule to extend the molecular size and investigate their...

The frontier orbital sequence of individual dicyanovinyl-substituted oligothiophene molecules is studied by means of scanning tunneling microscopy. On NaCl/Cu(111), the molecules are neutral, and the two lowest unoccupied molecular states are observed in the expected order of increasing energy. On NaCl/Cu(311), where the molecules are negatively charged, the sequence of two observed molecular o...

The improvement of molecular electronic devices such as organic light-emitting diodes requires fundamental knowledge about the structural and electronic properties of the employed molecules as well as their interactions with neighboring molecules or interfaces. We show that highly resolved scanning tunneling microscopy (STM) and spectroscopy (STS) are powerful tools to correlate the electronic ...

The study examined surface adsorption of fullerene C60 with anticancer drug procarbazine in gas and solvent (water) phases using the DFT method. In doing so, the structure of the procarbazine, fullerene and their derivatives were first geometrically optimized in three different configurations with a base set of 6-31 g * and B3LYP hybrid functions. Then, IR calculations, frontier molecular orbit...

To accelerate reactive events in molecular dynamics simulations we introduce a general bias potential scheme which depends only on the electronic degrees of freedom of the reactive system. This electronic reaction coordinate, which is expressed in terms of a penalty function of the one-electron orbital energies, has been applied to study different reaction pathways of s-cis-butadiene. Three dif...

In the present study, structural properties of 2-[(1H-benzimidazol-2-ylmethyl)-amino]-benzoic acid methyl ester have been studied extensively by spectral methods and X-ray crystallography. Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, NMR and electronic transitions were carried out by DFT using B3LYP functional combined with 6-31G(d) basis set. Natural bond o...

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...

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...